3.6l & 5.7l - Dtcs p0151 to p0339 Jeep Grand Cherokee WK2

Scheme 118

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

THEORY OF OPERATION

The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1, 275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.

WHEN MONITORED

Engine running for less than 30 seconds and the O2 Sensor Heater Temperature is less than 251° C (484° F) with battery voltage greater 10.99 Volts.

SET CONDITION

The Powertrain Control Module (PCM) detects that the 2/1 Oxygen Sensor signal voltage is below the minimum acceptable value. The DTC will set as Pending after one trip and Active after two trips. Three good trips to turn off the MIL.

POSSIBLE CAUSES

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 119

Scheme 120

Scheme 121

Scheme 122

Scheme 123

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) Turn the ignition on. With the scan tool, read DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to idle for at least 60 seconds. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. With the scan tool, read the active DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. (K43) O2 2/1 SIGNAL CIRCUIT Turn the ignition off. Disconnect the 2/1 O2 Sensor harness connector. Ignition on, engine not running. With the scan tool, monitor the 2/1 O2 Sensor voltage. Is the O2 Sensor voltage between 4.1 and 5.0 Volts? Yes Go To 3 . No Go To 5 .
3. O2 SENSOR Measure the voltage on the (K902) O2 Return Upstream circuit in the O2 Sensor harness connector. Is the voltage at 2.5 Volts? Yes Verify that there is good pin to terminal contact in the 2/1 Oxygen Sensor and Powertrain Control Module connectors. If OK, replace the 2/1 O2 Sensor. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (K902) O2 RETURN UPSTREAM CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C1 PCM harness connector. Measure the resistance between ground and the (K902) O2 Return Upstream circuit in the O2 Sensor harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K902) O2 Return Upstream circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
5. (K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C1 and C2 PCM harness connectors. Measure the resistance between ground and the (K43) O2 2/1 Signal circuit in the O2 Sensor harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K43) O2 2/1 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 6 .
6. (K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO THE (K902) O2 RETURN UPSTREAM CIRCUIT Measure the resistance between the (K43) O2 2/1 Signal circuit and the (K902) O2 Return Upstream circuit in the O2 Sensor harness connector. Is the resistance below 100 Ohms? Yes Repair the short between the (K902) O2 Return Upstream circuit and the (K43) O2 2/1 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. (K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO THE (Z903) HEATER GROUND CIRCUIT Measure the resistance between the (K43) O2 2/1 Signal circuit and the (Z903) O2 Heater ground circuit in the O2 Sensor harness connector. Is the resistance below 100 Ohms? Yes Repair the short between the (Z903) O2 Heater ground circuit and the (K43) O2 2/1 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 2/1 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the 2/1 O2 Sensor and Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0152-O2 SENSOR 2/1 CIRCUIT HIGH

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1, 275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.

Continuously with the engine running, no O2 sensor heater DTCs present, 2/1 Oxygen Sensor heater temperature within a specific range and battery voltage greater than 10.4 Volts.

The Powertrain Control Module (PCM) detects that the 2/1 Oxygen Sensor voltage is greater than the maximum acceptable value for a specific amount of time, based on O2 sensor heater temperature. The DTC will set as Pending after one trip and Active after two trips. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 124

Scheme 125

Scheme 126

Scheme 127

Scheme 128

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) NOTE: If an O2 sensor signal circuit is shorted to voltage, all O2 sensor voltage readings displayed on the scan tool will be approximately 5.0 Volts. Diagnose the sensor that set the most current DTC. Start the engine and allow it to idle for at least 60 seconds. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. With the scan tool, read the active DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. (K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Disconnect the C1 and C2 PCM harness connectors. Disconnect the 2/1 O2 Sensor harness connector. Turn the ignition on. Measure the voltage on the (K43) O2 Sensor 2/1 Signal circuit in the 2/1 O2 Sensor harness connector. NOTE: Measure the voltage in reference to ground, not the (K902) O2 Return Upstream circuit. Is there any voltage present? Yes Repair the short to voltage in the (K43) O2 Sensor 2/1 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. (K902) O2 RETURN UPSTREAM CIRCUIT SHORTED TO VOLTAGE Measure the voltage on the (K902) O2 Return Upstream circuit in the 2/1 O2 Sensor harness connector. Is there any voltage present? Yes Repair the short to voltage in the (K902) O2 Return Upstream circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. O2 SENSOR Turn the ignition off. Connect the C1 and C2 PCM harness connectors. Ignition on, engine not running. With the scan tool, monitor the 2/1 O2 Sensor voltage. Connect a jumper wire between the (K43) O2 2/1 Signal circuit and the (K902) O2 Return Upstream circuit in the O2 Sensor harness connector. Is the voltage between 2.3 and 2.7 Volts with the jumper wire in place? Yes Verify that there is good pin to terminal contact in the 2/1 Oxygen Sensor and Powertrain Control Module connectors. If OK, replace the 2/1 O2 Sensor. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 . NOTE: Remove the jumper wire before continuing.
5. (K43) O2 2/1 SIGNAL CIRCUIT OPEN Turn the ignition off. Disconnect the C1 and C2 PCM harness connectors. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K43) O2 2/1 Signal circuit from the 2/1 O2 Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open in the (K43) O2 2/1 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. (K902) O2 RETURN UPSTREAM CIRCUIT OPEN Measure the resistance of the (K902) O2 Return Upstream circuit from the O2 Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 7 . No Repair the open in the (K902) O2 Return Upstream circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the 2/1 Oxygen Sensor and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the 2/1 O2 Sensor and Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0153-O2 SENSOR 2/1 SLOW RESPONSE

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

For an aged O2 sensor, the response rate to the air/fuel change is slower than when it was new. The O2 sensor tends to move less with the same air/fuel changes in a given time frame. Therefore by observing the activity of voltage readings from the upstream O2 sensor, the quality of the O2 sensor can be detected.

With the ECT above 70 °C (158 °F), engine RPM between 1400 and 2300, vehicle speed between 64 and 96 kph (40 and 60 mph) and engine run time greater than three minutes.

The Powertrain Control Module (PCM) detects that the oxygen sensor signal does not switch adequately during monitoring. Two Trip Fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

DIAGNOSTIC TEST

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) NOTE: Check for contaminants that may have damaged the O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant. NOTE: After the repairs have been made, verify proper O2 Sensor operation. If all the O2 Sensor voltage readings have not returned to normal, follow the diagnostic procedure for the remaining O2 Sensors. Start the engine. Allow the engine to reach normal operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. With the scan tool, read DTCs. NOTE: It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data. Is the DTC Active or Pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. CHECKING THE EXHAUST SYSTEM FOR LEAKS Turn the ignition off. Raise the vehicle in accordance with the Service Information. WARNING: The normal operating temperature of the exhaust system is very high. Never work around or attempt to service any part of the exhaust system until it has cooled. Special care should be taken when working near the catalytic converter. The temperature of the converter rises to a high level after a short period of engine operating time. Connect Exhaust Cone (special tool #8404-EC, Exhaust Cone) or (special tool #8404-EC, Exhaust Cone) to Air Pressure Regulator (with hose) W-18-MIL-1146AS. CAUTION: The air pressure must not exceed 27.6 kPa (4 psi), otherwise engine damage can occur. Attach shop air to the air pressure regulator. Adjust the Air Pressure Regulator to 27.6 kPa (4 psi). Insert the exhaust cone into the vehicle tail pipe. If the vehicle is equipped with dual exhaust. Use the (special tool #8404-ECT, Exhaust Cone, Truck) with equipped attached plug, plug one side of the dual exhaust pipe. Pressurize the other as described above. Apply Mopar® Air Leak Detector PN# 05191804AA (or an equivalent leak finder liquid) to the following areas: All welded joints from the exhaust manifold to 152.4 mm (6 inches) behind the downstream O2 sensor O2 sensor seal points O2 sensor boss welds Flange/joint connection(s) Exhaust manifold to cylinder head connection(s) EGR solenoid gasket base and tube seal points (if equipped) Watch for the liquid/soapy water to bubble. Use the following definitions to help determine if system or component repair/replacement is necessary: Type 1 Leak is defined as a leak where very small foam like bubbles 1 mm (0.04 of an inch) or less appear. Any Type 1 or greater leaks found in welded joints, O2 sensor seal points or O2 sensor boss welds must be repaired or the component must be replaced. Type 2 Leak is defined as a leak where larger bubbles pea size, 8 mm (0.3 of an inch) or greater appear. Any Type 2 or greater leaks found in flange or joint connections, exhaust manifold to cylinder head connections or EGR gasket and tube seal points must be repaired or the components must be replaced Leak Location Repair required if results at 27.6 kPa (4 psi) reveal bubble size: Welded joints Type 1, 1 mm (0.04 of an inch) or greater O2 Sensor seal points Type 1, 1 mm (0.04 of an inch) or greater O2 Sensor boss welds Type 1, 1 mm (0.04 of an inch) or greater Flange / joint connections Type 2, 8 mm (0.3 of an inch) or greater Exhaust Manifold to cylinder head connections Type 2, 8 mm (0.3 of an inch) or greater EGR gasket and tube seal points Type 2, 8 mm (0.3 of an inch) or greater If a leak is found that matches the above definition, repair or replace the component as necessary. Once the repair is complete, repeat the procedure to verify that all leaks have been repaired. Were any exhaust leaks found? Yes Repair or replace the leaking exhaust parts as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. (K43) O2 2/1 SIGNAL CIRCUIT Turn the ignition off Disconnect the O2 Sensor harness connector. Ignition on, engine not running. Measure the voltage on the (K43) O2 2/1 Signal circuit in the O2 Sensor harness connector. Is the voltage between 4.1 and 5.0 Volts? Yes Go To 4 . No Check the (K43) O2 2/1 Signal circuit for a short to ground, open or short to voltage. If OK, replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
4. (K902) O2 RETURN UPSTREAM CIRCUIT Measure the voltage on the (K902) O2 Return Upstream circuit in the O2 Sensor harness connector. Is the voltage at 2.5 Volts? Yes Go To 5 . No Check the (K902) O2 Return Upstream circuit for a short to ground, open or short to voltage. If OK, replace and program the Powertrain Control Module in accordance with the Service Information. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. OXYGEN SENSOR NOTE: Check for signs of contaminants that may have damaged the O2 Sensor, such as contaminated fuel, unapproved silicone, oil and coolant. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the 2/1 Oxygen Sensor and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the 2/1 O2 Sensor and Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the 2/1 Oxygen Sensor in accordance with the Service Information. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0155-O2 SENSOR 2/1 HEATER PERFORMANCE

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

This diagnostic provides a continuous check of the O2 heater circuit during operation. The heater circuit is momentarily disabled to allow a resistance measurement to be taken to infer heater temperature. The current delivery to the heater is duty cycled to maintain a specific target temperature. The error from the target temperature is continuously monitored to assess heater performance.

Engine running and heater duty cycle greater than 0%. Battery voltage greater than 11.0 Volts.

No sensor output is received when the Powertrain Control Module (PCM) powers up the sensor heater. Two trip fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 129

Scheme 130

1. O2 SENSOR HEATER OPERATION Turn the ignition off. NOTE: Wait a minimum of eight minutes to allow the O2 Sensor to cool down before continuing the test. Allow the O2 Sensor voltage to stabilize between 4.6 and 5.0 Volts. Ignition on, engine not running. With the scan tool, actuate the O2 Heater Test. Using the scan tool, monitor 2/1 O2 Sensor voltage for at least two minutes. Does the voltage stay above 4.5 Volts? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. O2 SENSOR HEATER ELEMENT Turn the ignition off. NOTE: Allow the O2 sensor to cool down to room temperature. Disconnect the 2/1 O2 Sensor harness connector. Measure the resistance of the O2 Heater Element across the O2 Sensor connector between the O2 Heater Control terminal and the O2 Heater ground terminal. NOTE: O2 Heater Element resistance values should be measured at 21.1° C (70° F). The resistance value will vary with different temperature values. Is the resistance of the O2 Sensor Heater Element between 2.0 and 30.0 Ohms? Yes Go To 3 . No Verify that there is good pin to terminal contact in the 2/1 Oxygen Sensor and Powertrain Control Module connectors. If OK, replace the 2/1 O2 Sensor. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
3. (K199) O2 2/1 HEATER CONTROL CIRCUIT OPEN Disconnect the C2 PCM harness connector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K199) O2 2/1 Heater Control circuit from the O2 harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 0.5 of an Ohm? Yes Go To 4 . No Repair the excessive resistance in the (K199) O2 2/1 Heater Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
4. (Z903) O2 SENSOR HEATER GROUND CIRCUIT OPEN Measure the resistance between ground and the (Z903) O2 Heater ground circuit in the O2 Sensor harness connector. Is the resistance below 0.5 of an Ohm? Yes Go To 5 . No Repair the excessive resistance in the (Z903) O2 Heater ground circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 2/1 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Oxygen Sensor and Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0157-O2 SENSOR 2/2 CIRCUIT LOW

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1, 275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.

Engine running for less than 30 seconds and the O2 Sensor Heater Temperature is less than 251° C (484° F) with battery voltage greater 10.99 Volts.

The Powertrain Control Module (PCM) detects that the 2/2 Oxygen Sensor signal voltage is below the minimum acceptable value. The DTC will set as Pending after one trip and Active after two trips. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) Turn the ignition on. With the scan tool, read DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to idle for at least 60 seconds. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. With the scan tool, read the active DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. (K243) O2 2/2 SIGNAL CIRCUIT Turn the ignition off. Disconnect the 2/2 O2 Sensor harness connector. Ignition on, engine not running. With the scan tool, monitor the 2/2 O2 Sensor voltage. Is the O2 Sensor voltage between 4.1 and 5.0 Volts? Yes Go To 3 . No Go To 5 .
3. O2 SENSOR Measure the voltage on the (K904) O2 Return Downstream circuit in the O2 Sensor harness connector. Is the voltage at 2.5 Volts? Yes Verify that there is good pin to terminal contact in the 2/2 Oxygen Sensor and Powertrain Control Module connectors. If OK, replace the 2/2 O2 Sensor. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (K904) O2 RETURN DOWNSTREAM CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C2 PCM harness connector. Measure the resistance between ground and the (K904) O2 Return Downstream circuit in the O2 Sensor harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K904) O2 Return Downstream circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
5. (K243) O2 2/2 SIGNAL CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C1 and C2 PCM harness connectors. Measure the resistance between ground and the (K243) O2 2/2 Signal circuit in the O2 Sensor harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K243) O2 2/2 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 6 .
6. (K243) O2 2/2 SIGNAL CIRCUIT SHORTED TO THE (K904) O2 RETURN DOWNSTREAM CIRCUIT Measure the resistance between the (K243) O2 2/2 Signal circuit and the (K904) O2 Return Downstream circuit in the O2 Sensor harness connector. Is the resistance below 100 Ohms? Yes Repair the short between the (K904) O2 Return Downstream circuit and the (K243) O2 2/2 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. (K243) O2 2/2 SIGNAL CIRCUIT SHORTED TO THE (Z903) O2 2/2 HEATER GROUND CIRCUIT Measure the resistance between the (K243) O2 2/2 Signal circuit and the (Z903) O2 2/2 Heater ground circuit in the O2 Sensor harness connector. Is the resistance below 100 Ohms? Yes Repair the short between the (Z903) O2 2/2 Heater ground circuit and the (K243) O2 2/2 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 2/2 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the 2/2 Oxygen Sensor and Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0158-O2 SENSOR 2/2 CIRCUIT HIGH

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1, 275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.

Continuously with the engine running, no O2 sensor heater DTCs present, 2/2 Oxygen Sensor heater temperature within a specific range and battery voltage greater than 10.4 Volts.

The Powertrain Control Module (PCM) detects that the 2/2 Oxygen Sensor voltage is greater than the maximum acceptable value for a specific amount of time, based on O2 sensor heater temperature. The DTC will set as Pending after one trip and Active after two trips. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 131

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) NOTE: If an O2 sensor signal circuit is shorted to voltage, all O2 sensor voltage readings displayed on the scan tool will be approximately 5.0 Volts. Diagnose the sensor that set the most current DTC. Start the engine and allow it to idle for at least 60 seconds. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. (K243) O2 2/2 SIGNAL CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Disconnect the C1 and C2 PCM harness connectors. Disconnect the 2/2 O2 Sensor harness connector. Turn the ignition on. Measure the voltage on the (K243) O2 Sensor 2/2 Signal circuit in the O2 Sensor harness connector. NOTE: Measure the voltage in reference to ground, not the (K904) O2 Return Downstream circuit. Is there any voltage present? Yes Repair the short to voltage in the (K243) O2 Sensor 2/2 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. (K904) O2 RETURN DOWNSTREAM CIRCUIT SHORTED TO VOLTAGE Measure the voltage on the (K904) O2 Return Downstream circuit in the 2/2 O2 Sensor harness connector. Is there any voltage present? Yes Repair the short to voltage in the (K904) O2 Return Downstream circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. O2 SENSOR Turn the ignition off. Connect the C1 and C2 PCM harness connectors. Ignition on, engine not running. With the scan tool, monitor the 2/2 O2 Sensor voltage. Connect a jumper wire between the (K243) O2 2/2 Signal circuit and the (K904) O2 Return Downstream circuit in the 2/2 O2 Sensor harness connector. Is the voltage between 2.3 and 2.7 Volts with the jumper wire installed? Yes Verify that there is good pin to terminal contact in the 2/2 Oxygen Sensor and Powertrain Control Module connectors. If OK, replace the 2/2 O2 Sensor. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 . NOTE: Remove the jumper wire before continuing.
5. (K243) O2 2/2 SIGNAL CIRCUIT OPEN Turn the ignition off. Disconnect the C1 and C2 PCM harness connectors. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K243) O2 2/2 Signal circuit from the O2 Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open in the (K243) O2 2/2 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. (K904) O2 RETURN DOWNSTREAM CIRCUIT OPEN Measure the resistance of the (K904) O2 Return Downstream circuit from the O2 Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 7 . No Repair the open in the (K904) O2 Return Downstream circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 2/2 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Oxygen Sensor and Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0159-O2 SENSOR 2/2 SLOW RESPONSE

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The downstream O2 Sensor is located in the exhaust path behind the catalytic converter, is monitored for proper response to assure optimum catalytic converter efficiency. The downstream O2 response monitor is intended to diagnose a downstream O2 sensor that is not moving or stuck in a voltage window and to insure accurate information for catalyst monitor diagnosis.

With the engine running, vehicle speed above 96 kph (60 mph), throttle open for a minimum of 120 seconds, ECT greater than 70° C (158° F), catalytic converter temperature greater than 600° C (1112° F), and downstream oxygen sensor in a rich state. During a decel fuel shutoff event, the downstream oxygen sensor should switch from rich to lean within a specific time.

The Powertrain Control Module (PCM) monitors the downstream O2 sensor. If the PCM does not detect a rich to lean switch within a specific time during a decel fuel shutoff event, the monitor will fail. One trip fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) NOTE: Check for contaminants that may have damaged the O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant. NOTE: After the repairs have been made, verify proper O2 Sensor operation. If all the O2 Sensor voltage readings have not returned to normal, follow the diagnostic procedure for the remaining O2 Sensors. Start the engine. Allow the engine to reach normal operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. With a scan tool, read DTCs. NOTE: It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data. Is the DTC Active or Pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. CHECKING THE EXHAUST SYSTEM FOR LEAKS Turn the ignition off. Raise the vehicle in accordance with the Service Information. WARNING: The normal operating temperature of the exhaust system is very high. Never work around or attempt to service any part of the exhaust system until it has cooled. Special care should be taken when working near the catalytic converter. The temperature of the converter rises to a high level after a short period of engine operating time. Connect Exhaust Cone (special tool #8404-EC, Exhaust Cone) or (special tool #8404-EC, Exhaust Cone) to Air Pressure Regulator (with hose) W-18-MIL-1146AS. CAUTION: The air pressure must not exceed 27.6 kPa (4 psi), otherwise engine damage can occur. Attach shop air to the air pressure regulator. Adjust the Air Pressure Regulator to 27.6 kPa (4 psi). Insert the exhaust cone into the vehicle tail pipe. If the vehicle is equipped with dual exhaust. Use the (special tool #8404-ECT, Exhaust Cone, Truck) with equipped attached plug, plug one side of the dual exhaust pipe. Pressurize the other as described above. Apply Mopar® Air Leak Detector PN# 05191804AA (or an equivalent leak finder liquid) to the following areas: All welded joints from the exhaust manifold to 152.4 mm (6 inches) behind the downstream O2 sensor O2 sensor seal points O2 sensor boss welds Flange/joint connection(s) Exhaust manifold to cylinder head connection(s) EGR solenoid gasket base and tube seal points (if equipped) Watch for the liquid/soapy water to bubble. Use the following definitions to help determine if system or component repair/replacement is necessary: Type 1 Leak is defined as a leak where very small foam like bubbles 1 mm (0.04 of an inch) or less appear. Any Type 1 or greater leaks found in welded joints, O2 sensor seal points or O2 sensor boss welds must be repaired or the component must be replaced. Type 2 Leak is defined as a leak where larger bubbles pea size, 8 mm (0.3 of an inch) or greater appear. Any Type 2 or greater leaks found in flange or joint connections, exhaust manifold to cylinder head connections, or EGR gasket and tube seal points must be repaired or the components must be replaced Leak Location Repair required if results at 27.6 kPa (4 psi) reveal bubble size: Welded joints Type 1, 1 mm (0.04 of an inch) or greater O2 Sensor seal points Type 1, 1 mm (0.04 of an inch) or greater O2 Sensor boss welds Type 1, 1 mm (0.04 of an inch) or greater Flange / joint connections Type 2, 8 mm (0.3 of an inch) or greater Exhaust Manifold to cylinder head connections Type 2, 8 mm (0.3 of an inch) or greater EGR gasket and tube seal points Type 2, 8 mm (0.3 of an inch) or greater If a leak is found that matches the above definition, repair or replace the component as necessary. Once the repair is complete, repeat the procedure to verify that all leaks have been repaired. Were any exhaust leaks found? Yes Repair or replace the leaking exhaust parts as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. (K243) O2 2/2 SIGNAL CIRCUIT Turn the ignition off Disconnect the 2/2 O2 Sensor harness connector. Ignition on, engine not running. Measure the voltage on the (K243) O2 2/2 Signal circuit in the O2 Sensor harness connector. Is the voltage between 4.1 and 5.0 Volts? Yes Go To 4 . No Check the (K243) O2 2/2 Signal circuit for a short to ground, open, or short to voltage. If OK, replace and program the Powertrain Control Module in accordance with the service information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
4. (K904) O2 RETURN DOWNSTREAM CIRCUIT Measure the voltage on the (K904) O2 Return Downstream circuit in the 2/2 O2 Sensor harness connector. Is the voltage at 2.5 Volts? Yes Go To 5 . No Check the (K904) O2 Return Downstream circuit for a short to ground, open, or short to voltage. If OK, replace and program the Powertrain Control Module in accordance with the service information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. O2 SENSOR NOTE: Check for signs of contaminants that may have damaged the O2 Sensor, such as contaminated fuel, unapproved silicone, oil and coolant. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the 2/2 Oxygen Sensor and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched, or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the 2/2 O2 Sensor and Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the 2/2 Oxygen Sensor in accordance with the Service Information. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0160-O2 SENSOR 2/2 NO ACTIVITY DETECTED

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The downstream O2 Sensor is located in the exhaust path behind the catalytic converter, is monitored for proper response to assure optimum catalytic converter efficiency. The downstream O2 response monitor is intended to diagnose a downstream O2 sensor that is not moving or stuck in a voltage window and to insure accurate information for catalyst monitor diagnosis.

Vehicle is started and driven between 32 and 88.5 km/h (20 and 55 mph) with the Throttle open for a minimum of 120 seconds. Coolant greater than 70° C (158° F). Catalytic Converter Temp greater than 600° C (1112° F) and EVAP Purge is active.

The oxygen sensor signal voltage switches less than 16 times from lean to rich within 20 seconds during monitoring. Two Trip Fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC NOTE: After the repairs have been made, verify proper O2 Sensor operation. If all the O2 Sensor voltage readings have not returned to normal, follow the diagnostic procedure for the remaining O2 Sensors. NOTE: Check for contaminants that may have damaged the O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant. Start the engine. Allow the engine to reach normal operating temperature. With the scan tool, select View DTCs. NOTE: It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data. Is the DTC Active or Pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. CHECKING THE EXHAUST SYSTEM FOR LEAKS Turn the ignition off. Raise the vehicle in accordance with the Service Information. WARNING: The normal operating temperature of the exhaust system is very high. Never work around or attempt to service any part of the exhaust system until it has cooled. Special care should be taken when working near the catalytic converter. The temperature of the converter rises to a high level after a short period of engine operating time. Connect Exhaust Cone (special tool #8404-EC, Exhaust Cone) or (special tool #8404-EC, Exhaust Cone) to Air Pressure Regulator (with hose) W-18-MIL-1146AS. CAUTION: The air pressure must not exceed 27.6 kPa (4 psi), otherwise engine damage can occur. Attach shop air to the air pressure regulator. Adjust the Air Pressure Regulator to 27.6 kPa (4 psi). Insert the exhaust cone into the vehicle tail pipe. If the vehicle is equipped with dual exhaust. Use the (special tool #8404-ECT, Exhaust Cone, Truck) with equipped attached plug, plug one side of the dual exhaust pipe. Pressurize the other as described above. Apply Mopar® Air Leak Detector PN# 05191804AA (or an equivalent leak finder liquid) to the following areas: All welded joints from the exhaust manifold to 152.4 mm (6 inches) behind the downstream O2 sensor O2 sensor seal points O2 sensor boss welds Flange/joint connection(s) Exhaust manifold to cylinder head connection(s) EGR solenoid gasket base and tube seal points (if equipped) Watch for the liquid/soapy water to bubble. Use the following definitions to help determine if system or component repair/replacement is necessary: Type 1 Leak is defined as a leak where very small foam like bubbles 1 mm (0.04 of an inch) or less appear. Any Type 1 or greater leaks found in welded joints, O2 sensor seal points or O2 sensor boss welds must be repaired or the component must be replaced. Type 2 Leak is defined as a leak where larger bubbles pea size, 8 mm (0.3 of an inch) or greater appear. Any Type 2 or greater leaks found in flange or joint connections, exhaust manifold to cylinder head connections or EGR gasket and tube seal points must be repaired or the components must be replaced. Leak Location Repair required if results at 27.6 kPa (4 psi) reveal bubble size: Welded joints Type 1, 1 mm (0.04 of an inch) or greater O2 Sensor seal points Type 1, 1 mm (0.04 of an inch) or greater O2 Sensor boss welds Type 1, 1 mm (0.04 of an inch) or greater Flange / joint connections Type 2, 8 mm (0.3 of an inch) or greater Exhaust Manifold to cylinder head connections Type 2, 8 mm (0.3 of an inch) or greater EGR gasket and tube seal points Type 2, 8 mm (0.3 of an inch) or greater If a leak is found that matches the above definition, repair or replace the component as necessary. Once the repair is complete, repeat the procedure to verify that all leaks have been repaired. Were any exhaust leaks found? Yes Repair or replace the leaking exhaust parts as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. (K243) O2 2/2 SIGNAL CIRCUIT Turn the ignition off Disconnect the 2/2 O2 Sensor harness connector. Ignition on, engine not running. Measure the voltage on the (K243) O2 2/2 Signal circuit in the O2 Sensor harness connector. Is the voltage between 4.1 and 5.0 Volts? Yes Go To 4 . No Check the (K243) O2 2/2 Signal circuit for a short to ground, open or short to voltage. If OK, replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
4. (K904) O2 RETURN DOWNSTREAM CIRCUIT Measure the voltage on the (K904) O2 Return Downstream circuit in the O2 Sensor harness connector. Is the voltage at 2.5 Volts? Yes Go To 5 . No Check the (K904) O2 Return Downstream circuit for a short to ground, open or short to voltage. If OK, replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. OXYGEN SENSOR NOTE: Check for signs of contaminants that may have damaged the O2 Sensor, such as contaminated fuel, unapproved silicone, oil and coolant. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the 2/2 Oxygen Sensor and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Were any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the 2/2 Oxygen Sensor in accordance with the Service Information. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0161-O2 SENSOR 2/2 HEATER PERFORMANCE

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

This diagnostic provides a continuous check of the O2 heater circuit during operation. The heater circuit is momentarily disabled to allow a resistance measurement to be taken to infer heater temperature. The current delivery to the heater is duty cycled to maintain a specific target temperature. The error from the target temperature is continuously monitored to assess heater performance.

Engine running and heater duty cycle greater than 0%. Battery voltage greater than 11.0 Volts.

No sensor output is received when the PCM powers up the sensor heater. Two trip fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 132

1. O2 SENSOR HEATER OPERATION Turn the ignition off. NOTE: Wait a minimum of eight minutes to allow the O2 Sensor to cool down before continuing the test. Allow the O2 Sensor voltage to stabilize between 4.6 and 5.0 Volts. Ignition on, engine not running. With the scan tool, actuate the O2 Heater Test. With the scan tool, monitor 2/2 O2 Sensor voltage for at least two minutes. Does the voltage stay above 4.5 Volts? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. O2 SENSOR HEATER ELEMENT Turn the ignition off. NOTE: Allow the O2 sensor to cool down to room temperature. Disconnect the O2 Sensor harness connector. Measure the resistance of the 2/2 O2 Heater Element, between the O2 Heater Control terminal and the O2 Heater ground terminal in the O2 Sensor connector. NOTE: O2 Heater Element resistance values should be measured at 21.1° C (70° F). The resistance value will vary with different temperature values. Is the resistance of the O2 Sensor Heater Element between 2.0 and 30.0 Ohms? Yes Go To 3 . No Verify that there is good pin to terminal contact in the 2/2 Oxygen Sensor and Powertrain Control Module connectors. If OK, replace the 2/2 O2 Sensor. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
3. (K399) O2 2/2 HEATER CONTROL CIRCUIT OPEN Disconnect the C3 PCM harness connector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K399) O2 2/2 Heater Control circuit from the O2 harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 0.5 of an Ohm? Yes Go To 4 . No Repair the excessive resistance in the (K399) O2 2/2 Heater Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
4. (Z903) O2 2/2 HEATER GROUND CIRCUIT OPEN Measure the resistance between ground and the (Z903) O2 2/2 Heater ground circuit in the O2 Sensor harness connector. Is the resistance below 0.5 of an Ohm? Yes Go To 5 . No Repair the excessive resistance in the (Z903) O2 2/2 Heater ground circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 2/2 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Oxygen Sensor and Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

Scheme 133

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fuel feedback system will maintain a stoichiometric fuel/air mixture, 14.7:1, by modifying the injector pulse width according to the oxygen content of the exhaust gas. The Powertrain Control Module (PCM) makes short term and long term fuel corrections to maintain stoichiometric fuel/air ratio for best catalytic converter efficiency. Short term fuel correction is based on upstream O2 sensor output and is designed for quick engine response. The long term fuel correction compensated for variations in the engine specifications, sensor tolerances and component aging and is designed to correct rich and lean conditions over a longer period of time.

With the engine running in closed loop mode, the ambient/battery temperature above -6.7°C (20°F) and altitude below 2590.8 m (8500 ft).

If the Powertrain Control Module (PCM) multiplies short term compensation by long term adaptive and a certain percentage is exceeded for two trips, a freeze frame is stored, the MIL illuminates and a trouble code is stored. Two Trip Fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) Diagnose all other DTCs before continuing. NOTE: Check for contaminants that may have damaged an O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant. Start the engine. Allow the engine to reach normal operating temperature. With the scan tool, read DTCs. NOTE: It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data. Is the DTC Active or Pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. CHECKING FUEL PRESSURE WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) to the fuel rail. Ignition on, engine not running. With the scan tool, actuate the Fuel System test and observe the fuel pressure gauge. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Turn the ignition off. Choose a conclusion that best matches your fuel pressure reading. Within Specification Go To 3 . Above Specification Replace the fuel filter/pressure regulator. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . Below Specification Go To 13 . CAUTION: Before Proceeding Stop All Actuations.
3. CHECKING THE EXHAUST SYSTEM FOR LEAKS Turn the ignition off. Raise the vehicle in accordance with the Service Information. WARNING: The normal operating temperature of the exhaust system is very high. Never work around or attempt to service any part of the exhaust system until it has cooled. Special care should be taken when working near the catalytic converter. The temperature of the converter rises to a high level after a short period of engine operating time. Connect Exhaust Cone (special tool #8404-EC, Exhaust Cone) or (special tool #8404-EC, Exhaust Cone) to Air Pressure Regulator (with hose) W-18-MIL-1146AS. CAUTION: Adjust the Air Pressure Regulator to 27.6 kPa (4 psi). Attach shop air to the air pressure regulator. Adjust the Air Pressure Regulator to 27.6 kPa (4 psi). Insert the exhaust cone into the vehicle tail pipe. If the vehicle is equipped with dual exhaust. Use the (special tool #8404-ECT, Exhaust Cone, Truck) with equipped attached plug, plug one side of the dual exhaust pipe. Pressurize the other as described above. Apply Mopar® Air Leak Detector PN# 05191804AA (or an equivalent leak finder liquid) to the following areas: All welded joints from the exhaust manifold to 152.4 mm (6 inches) behind the downstream O2 sensor O2 sensor seal points O2 sensor boss welds Flange/joint connection(s) Exhaust manifold to cylinder head connection(s) EGR solenoid gasket base and tube seal points (if equipped) Watch for the liquid/soapy water to bubble. Use the following definitions to help determine if system or component repair/replacement is necessary: Type 1 Leak is defined as a leak where very small foam like bubbles 1 mm (0.04 of an inch) or less appear. Any Type 1 or greater leaks found in welded joints, O2 sensor seal points or O2 sensor boss welds must be repaired or the component must be replaced. Type 2 Leak is defined as a leak where larger bubbles pea size, 8 mm (0.3 of an inch) or greater appear. Any Type 2 or greater leaks found in flange or joint connections, exhaust manifold to cylinder head connections or EGR gasket and tube seal points must be repaired or the components must be replaced Leak Location Repair required if results at 27.6 kPa (4 psi) reveal bubble size: Welded joints Type 1, 1 mm (0.04 of an inch) or greater O2 Sensor seal points Type 1, 1 mm (0.04 of an inch) or greater O2 Sensor boss welds Type 1, 1 mm (0.04 of an inch) or greater Flange / joint connections Type 2, 8 mm (0.3 of an inch) or greater Exhaust Manifold to cylinder head connections Type 2, 8 mm (0.3 of an inch) or greater EGR gasket and tube seal points Type 2, 8 mm (0.3 of an inch) or greater If a leak is found that matches the above definition, repair or replace the component as necessary. Once the repair is complete, repeat the procedure to verify that all leaks have been repaired. Were any exhaust leaks found? Yes Repair or replace the leaking exhaust parts as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. O2 SENSOR OPERATION Start the engine. Allow the engine to reach normal operating temperature. NOTE: If one of the O2 Sensor's Signal or Return circuit is shorted to ground the scan tool will display all O2 Sensor voltage readings low. The O2 Sensor that is shorted to ground will display a voltage reading near or at 0 Volts. NOTE: If one of the O2 Sensor Signal or Return circuits are shorted to voltage, the scan tool will display all O2 Sensor voltage readings high. NOTE: After the repairs have been made, verify proper O2 Sensor operation. If all the O2 Sensor voltage readings have not returned to normal, follow the diagnostic procedure for the remaining O2 Sensors. With the scan tool, monitor all of the O2 Sensor voltage readings. Is the voltage switching between 2.5 and 3.4 Volts for all the O2 Sensors? Yes Go To 5 . No Go To 9 .
5. 1/1 O2 SENSOR HEATER OPERATION Turn the ignition off. NOTE: Wait a minimum of 10 minutes to allow the O2 Sensor to cool down before continuing the test. Allow the O2 Sensor voltage to stabilize at 5.0 Volts. Ignition on, engine not running. With the scan tool, actuate the 1/1 O2 Heater Test. Using the scan tool, monitor 1/1 O2 Sensor voltage for at least two minutes. Does the voltage stay above 4.5 Volts? Yes Verify that there is good pin to terminal contact in the O2 Sensor and Powertrain Control Module connectors. Replace the 1/1 O2 Sensor if no problems were found with the connectors. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 6 .
6. MAP SENSOR OPERATION Ignition on, engine not running. With the scan tool, read the Barometric Pressure. NOTE: The Barometric Pressure should be approximately equal to the actual barometric pressure. If necessary, compare the value to the value of a known good vehicle of a similar make and model. Turn the ignition off. Connect a Vacuum Gauge to a Manifold Vacuum source. Start the engine. Allow the engine to idle. NOTE: If engine will not idle, maintain a constant RPM above idle. Using the scan tool, read the MAP Sensor vacuum value. Is the scan tool reading within 1" of Hg on the Vacuum Gauge reading and the barometric pressure comparable to a know good vehicle? Yes Go To 7 . No Verify that there is good pin to terminal contact in the MAP Sensor and Powertrain Control Module connectors. Replace the MAP Sensor if no problems were found with the connectors. Refer to «SENSOR, MANIFOLD AIR PRESSURE (MAP), REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. ECT SENSOR OPERATION NOTE: For this test to be valid, the thermostat must be operating correctly. NOTE: This test works best if performed on a cold engine (cold soak) Ignition on, engine not running. With the scan tool, read the Engine Coolant Temperature (ECT) Sensor value. If the engine was allowed to sit overnight (cold soak), the temperature value should be a sensible value that is somewhere close to the ambient temperature. NOTE: If engine coolant temperature is above 82° C (180° F), allow the engine to cool until 65° C (150° F) is reached. Start the Engine. During engine warm-up, monitor the ECT Sensor value. The temperature value change should be a smooth transition from start up to normal operating temperature 82° C (180° F). The value should reach at least 82° C (180° F). Did the ECT value increase smoothly and did it reach at least 82° C (180° F)? Yes Go To 8 . No Verify that there is good pin to terminal contact in the ECT Sensor and Powertrain Control Module connectors. Replace the ECT Sensor if no problems were found with the connectors. Refer to «SENSOR, COOLANT TEMPERATURE, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/accessory-drive-belts/#engine-cooling-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
8. ENGINE MECHANICAL Turn the ignition off. Check for any of the following conditions/mechanical problems: AIR INDUCTION SYSTEM - must be free from leaks. ENGINE VACUUM - must be at least 13 inches in neutral ENGINE VALVE TIMING - must be within specifications ENGINE COMPRESSION - must be within specifications ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks. ENGINE PCV SYSTEM - must flow freely TORQUE CONVERTER STALL SPEED - must be within specifications POWER BRAKE BOOSTER - no internal vacuum leaks FUEL - must be free of contamination FUEL INJECTOR - plugged or restricted injector; control wire not connected to correct injector Are there any engine mechanical problems? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 12 .
9. 1/1 O2 SENSOR Ignition on, engine not running. Disconnect the 1/1 O2 Sensor harness connector. With the scan tool, monitor the 1/1 O2 Sensor voltage. O2 Sensor voltage should read between 4.1 and 5.0 Volts on the scan tool with the connector disconnected. Connect a jumper wire between the (K41) Signal circuit and the (K902) O2 Return Upstream circuit in the O2 Sensor harness connector. NOTE: The voltage should drop from between 4.1 and 5.0 Volts to 2.5 Volts with the jumper wire in place. Did the O2 Sensor voltage change from between 4.1 and 5.0 Volts to 2.5 Volts with the jumper wire installed? Yes Verify that there is good pin to terminal contact in the O2 Sensor and Powertrain Control Module connectors. Replace the 1/1 O2 Sensor if no problems were found with the connectors. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 10 . NOTE: Remove the jumper wire before continuing.
10. (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT With the scan tool, monitor the 1/1 O2 Sensor voltage reading with the jumper wire removed. NOTE: The scan tool will display all O2 Sensor voltage readings approximately 5.0 Volts when only one O2 Sensor's Signal circuit is shorted to voltage. NOTE: The scan tool will display one O2 Sensor voltage close to zero and the others will read lower than normal when one O2 Sensor Signal circuit contains excessive resistance. Is the voltage between 4.1 and 5.0 Volts? Yes Go To 11 . No Check the (K41) O2 Sensor 1/1 Signal circuit for a short to ground, open or short to voltage. Inspect the O2 Sensor connector and the PCM harness connector. If OK, replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
11. (K902) O2 RETURN UPSTREAM CIRCUIT Measure the voltage on the (K902) O2 Return Upstream circuit in the O2 Sensor harness connector. Is the voltage at 2.5 Volts? Yes Go To 12 . No Check the O2 Return circuit for a short to ground, open or short to voltage. Inspect the O2 Sensor connector and the PCM harness connector. If OK, replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
12. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Sensors and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the 1/1 O2 Sensor and Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
13. RESTRICTED FUEL SUPPLY LINE WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Raise vehicle on hoist and disconnect the fuel pressure line at the fuel pump module. Install Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) between the fuel supply line and the fuel pump module. Ignition on, engine not running. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Is the fuel pressure within specification? Yes Repair or replace fuel supply line as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 14 . CAUTION: Stop All Actuations.
14. FUEL PUMP INLET STRAINER WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Turn the ignition off. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer. Is the Fuel Inlet Strainer plugged? Yes Replace the Fuel Pump Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
15. FUEL PUMP MODULE Repair Verify that there is good pin to terminal contact in the Fuel Pump Module and Powertrain Control Module connectors. Replace the Fuel Pump Module if no problems were found with the connectors. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0172-FUEL SYSTEM 1/1 RICH

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fuel feedback system will maintain a stoiciometric fuel/air mixture, 14.7:1, by modifying the injector pulsewidth according to the oxygen content of the exhaust gas. The Powertrain Control Module (PCM) makes short term and long term fuel corrections to maintain stoiciometric fuel/air ratio for best catalytic converter efficiency. Short term fuel correction is based on upstream O2 sensor output and is designed for quick engine response. The long term fuel correction compensated for variations in the engine specifications, sensor tolerances and component aging and is designed to correct rich and lean conditions over a longer period of time.

With the engine running in closed loop mode, the ambient/battery temperature above -6.7°C (20°F) and altitude below 2590.8 m (8500 ft).

If the Powertrain Control Module (PCM) multiplies short term compensation by long term adaptive and a purge fuel multiplier and the result is below a certain value for 30 seconds over two trips, a freeze frame is stored, the MIL illuminates and a trouble code is stored. Two Trip Fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) NOTE: Check for contaminates that may have damaged an O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant. Start the engine. Allow the engine to reach normal operating temperature. With the scan tool, read DTCs. NOTE: It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data. Is the DTC Active or Pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. CHECKING FUEL PRESSURE WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) to the fuel rail. Ignition on, engine not running. Using the scan tool, actuate the Fuel System test and observe the fuel pressure gauge. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Turn the ignition off. Choose a conclusion that best matches your fuel pressure reading. Within Specification Go To 3 . Above Specification Replace the fuel filter/pressure regulator. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . CAUTION: Before Proceeding Stop All Actuations.
3. O2 SENSOR OPERATION Start the engine. Allow the engine to reach normal operating temperature. NOTE: If one of the O2 Sensors Signal or Return circuit is shorted to ground or voltage, all the other O2 Sensor voltage readings will be affected. NOTE: After the repairs have been made, verify proper O2 Sensor operation. If all the O2 Sensor voltage readings have not returned to normal, follow the diagnostic procedure for the remaining O2 Sensors. Using the scan tool, monitor the 1/1 O2 Sensor voltage reading. Is the voltage switching between 2.5 and 3.4 Volts? Yes Go To 4 . No Go To 9 .
4. 1/1 O2 SENSOR HEATER OPERATION Turn the ignition off. NOTE: Wait a minimum of 10 minutes to allow the O2 Sensor to cool down before continuing the test. Allow the O2 Sensor voltage to stabilize at 5.0 Volts. Ignition on, engine not running. Using the scan tool, perform the 1/1 O2 Heater Test. Using the scan tool, monitor the O2 Sensor voltage while performing the Heater test for at least two minutes. Does the voltage stay above 4.5 Volts during the Heater test? Yes Verify that there is good pin to terminal contact in the O2 Sensor and Powertrain Control Module connectors. Replace the 1/1 O2 Sensor if no problems were found with the connectors. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 .
5. MAP SENSOR OPERATION Ignition on, engine not running. With the scan tool, read the Barometric Pressure. NOTE: The Barometric Pressure should be approximately equal to the actual barometric pressure. If necessary, compare the Barometric Pressure value of this vehicle to the value of a known good vehicle of a similar make and model. Turn the ignition off. Connect a Vacuum Gauge to a Manifold Vacuum source. Start the engine. Allow the engine to idle. NOTE: If engine will not idle, maintain a constant RPM above idle. With the scan tool, read the MAP Sensor vacuum value. Is the scan tool reading for MAP Vacuum within 1 inch of the Vacuum Gauge reading and is the Barometric Pressure reading of the vehicle the approximately the same as actual Barometric Pressure? Yes Go To 6 . No Verify that there is good pin to terminal contact in the MAP Sensor and Powertrain Control Module connectors. Replace the MAP Sensor if no problems were found with the connectors. Refer to «SENSOR, MANIFOLD AIR PRESSURE (MAP), REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . NOTE: Remove the vacuum gauge before continuing.
6. ECT SENSOR OPERATION NOTE: For this test to be valid, the thermostat must be operating correctly. NOTE: This test works best if performed on a cold engine (cold soak) Ignition on, engine not running. With the scan tool, read the Engine Coolant Temperature Sensor value. If the engine was allowed to sit overnight (cold soak), the temperature value should be a sensible value that is somewhere close to the ambient temperature. NOTE: If engine coolant temperature is above 82° C (180° F), allow the engine to cool until 65° C (150° F) is reached. Start the Engine. During engine warm-up, monitor the Engine Coolant Temperature value. The temp value change should be a smooth transition from start up to normal operating temp 82° C (180° F). The value should reach at least 82° C (180° F). Did the ECT value increase smoothly and reach at least 82° C (180° F)? Yes Go To 7 . No Verify that there is good pin to terminal contact in the ECT Sensor and Powertrain Control Module connectors. Replace the Engine Coolant Temperature Sensor if no problems were found with the connectors. Refer to «SENSOR, COOLANT TEMPERATURE, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/accessory-drive-belts/#engine-cooling-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. EVAP PURGE SOLENOID OPERATION Turn the ignition off. Disconnect the hoses at the EVAP Purge Solenoid. Using a hand vacuum pump, apply 10 inches of vacuum to the EVAP Purge Solenoid vacuum source port on the component side. Did the EVAP Purge Solenoid hold vacuum? Yes Go To 8 . No Verify that there is good pin to terminal contact in the Solenoid and Powertrain Control Module connectors. Replace the EVAP Purge Solenoid if no problems were found with the connectors. Refer to «SOLENOID, EVAPORATIVE EMISSIONS PURGE, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#emissions-control) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . NOTE: Connect the vacuum hoses before continuing.
8. ENGINE MECHANICAL Check for any of the following conditions/mechanical problems. AIR INDUCTION SYSTEM - must be free from leaks. ENGINE VACUUM - must be at least 13 inches in neutral ENGINE VALVE TIMING - must be within specifications ENGINE COMPRESSION - must be within specifications ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks. ENGINE PCV SYSTEM - must flow freely TORQUE CONVERTER STALL SPEED - must be within specifications POWER BRAKE BOOSTER - no internal vacuum leaks FUEL - must be free of contamination FUEL INJECTOR - plugged or restricted injector; control wire not connected to correct injector Are there any engine mechanical problems? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 12 .
9. 1/1 O2 SENSOR NOTE: Perform the following test on the O2 Sensors whose voltage was not switching properly in the previous step. Ignition on, engine not running. Disconnect the 1/1 O2 Sensor harness connector. With the scan tool, monitor the 1/1 O2 Sensor voltage. O2 Sensor voltage should read between 4.1 and 5.0 Volts on the scan tool with the connector disconnected. Connect a jumper wire between the (K41) O2 Sensor 1/1 Signal circuit and the (K902) O2 Return Upstream circuit in the O2 Sensor harness connector. NOTE: The voltage should drop from between 4.1 and 5.0 Volts down to 2.5 Volts with the jumper wire connected. Did the O2 Sensor voltage drop from between 4.1 and 5.0 Volts to 2.5 Volts when the jumper wire was installed? Yes Verify that there is good pin to terminal contact in the O2 Sensor and Powertrain Control Module connectors. Replace the 1/1 O2 Sensor if no problems were found with the connectors. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 10 . NOTE: Remove the jumper wire before continuing.
10. (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT Measure the voltage on the (K41) O2 Sensor 1/1 Signal circuit in the O2 Sensor harness connector. Is the voltage between 4.1 and 5.0 Volts? Yes Go To 11 . No Check the (K41) O2 Sensor 1/1 Signal circuit for damage, short to ground, open or short to voltage. Inspect the O2 Sensor connector and the PCM harness connector. If OK, replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
11. (K902) O2 SENSOR RETURN UPSTREAM CIRCUIT Measure the voltage on the (K902) O2 Return Upstream circuit in the 1/1 O2 Sensor harness connector. Is the voltage at 2.5 Volts? Yes Go To 12 . No Check the (K902) O2 Return Upstream circuit for damage, short to ground, open or short to voltage. Inspect the O2 Sensor connector and the PCM harness connector. If OK, replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . NOTE: Turn the ignition off before continuing.
12. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Sensors and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the 1/1 O2 Sensor and Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0174-FUEL SYSTEM 2/1 LEAN

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fuel feedback system will maintain a stoichiometric fuel/air mixture, 14.7:1, by modifying the injector pulse width according to the oxygen content of the exhaust gas. The Powertrain Control Module (PCM) makes short term and long term fuel corrections to maintain stoichiometric fuel/air ratio for best catalytic converter efficiency. Short term fuel correction is based on upstream O2 sensor output and is designed for quick engine response. The long term fuel correction compensated for variations in the engine specifications, sensor tolerances and component aging and is designed to correct rich and lean conditions over a longer period of time.

With the engine running in closed loop mode, the ambient/battery temperature above -6.7°C (20°F) and altitude below 2590.8 m (8500 ft).

If the Powertrain Control Module (PCM) multiplies short term compensation by long term adaptive and a certain percentage is exceeded for two trips, a freeze frame is stored, the MIL illuminates and a trouble code is stored. Two Trip Fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) NOTE: Check for contaminants that may have damaged an O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant. Diagnose all other DTCs before continuing. Start the engine. Allow the engine to reach normal operating temperature. With the scan tool, read DTCs. NOTE: It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data. Is the DTC Active or Pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. CHECKING FUEL PRESSURE WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) to the fuel rail. Ignition on, engine not running. Using the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Turn the ignition off. Choose a conclusion that best matches your fuel pressure reading. Within Specification Go To 3 . Above Specification Replace the fuel filter/pressure regulator. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . Below Specification Go To 13 . CAUTION: Before Proceeding Stop All Actuations.
3. CHECKING THE EXHAUST SYSTEM FOR LEAKS Turn the ignition off. Raise the vehicle in accordance with the Service Information. WARNING: The normal operating temperature of the exhaust system is very high. Never work around or attempt to service any part of the exhaust system until it has cooled. Special care should be taken when working near the catalytic converter. The temperature of the converter rises to a high level after a short period of engine operating time. Connect Exhaust Cone (special tool #8404-EC, Exhaust Cone) or (special tool #8404-EC, Exhaust Cone) to Air Pressure Regulator (with hose) W-18-MIL-1146AS. CAUTION: The air pressure must not exceed 27.6 kPa (4 psi), otherwise engine damage can occur. Attach shop air to the air pressure regulator. Adjust the Air Pressure Regulator to 27.6 kPa (4 psi). Insert the exhaust cone into the vehicle tail pipe. If the vehicle is equipped with dual exhaust. Use the (special tool #8404-ECT, Exhaust Cone, Truck) with equipped attached plug, plug one side of the dual exhaust pipe. Pressurize the other as described above. Apply Mopar® Air Leak Detector PN# 05191804AA (or an equivalent leak finder liquid) to the following areas: All welded joints from the exhaust manifold to 152.4 mm (6 inches) behind the downstream O2 sensor O2 sensor seal points O2 sensor boss welds Flange/joint connection(s) Exhaust manifold to cylinder head connection(s) EGR solenoid gasket base and tube seal points (if equipped) Watch for the liquid/soapy water to bubble. Use the following definitions to help determine if system or component repair/replacement is necessary: Type 1 Leak is defined as a leak where very small foam like bubbles 1 mm (0.04 of an inch) or less appear. Any Type 1 or greater leaks found in welded joints, O2 sensor seal points or O2 sensor boss welds must be repaired or the component must be replaced. Type 2 Leak is defined as a leak where larger bubbles pea size, 8 mm (0.3 of an inch) or greater appear. Any Type 2 or greater leaks found in flange or joint connections, exhaust manifold to cylinder head connections or EGR gasket and tube seal points must be repaired or the components must be replaced Leak Location Repair required if results at 27.6 kPa (4 psi) reveal bubble size: Welded joints Type 1, 1 mm (0.04 of an inch) or greater O2 Sensor seal points Type 1, 1 mm (0.04 of an inch) or greater O2 Sensor boss welds Type 1, 1 mm (0.04 of an inch) or greater Flange / joint connections Type 2, 8 mm (0.3 of an inch) or greater Exhaust Manifold to cylinder head connections Type 2, 8 mm (0.3 of an inch) or greater EGR gasket and tube seal points Type 2, 8 mm (0.3 of an inch) or greater If a leak is found that matches the above definition, repair or replace the component as necessary. Once the repair is complete, repeat the procedure to verify that all leaks have been repaired. Were any exhaust leaks found? Yes Repair or replace the leaking exhaust parts as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. O2 SENSOR OPERATION Start the engine. Allow the engine to reach normal operating temperature. NOTE: If one of the O2 Sensor's Signal or Return circuit is shorted to ground the scan tool will display all O2 Sensor voltage readings low. The O2 Sensor that is shorted to ground will display a voltage reading near or at 0 Volts. NOTE: If one of the O2 Sensor Signal or Return circuits are shorted to voltage, the scan tool will display all O2 Sensor voltage readings high. NOTE: After the repairs have been made, verify proper O2 Sensor operation. If all the O2 Sensor voltage readings have not returned to normal, follow the diagnostic procedure for the remaining O2 Sensors. Using the scan tool, monitor the 2/1 O2 Sensor voltage reading. Is the voltage switching between 2.5 and 3.4 Volts? Yes Go To 5 . No Go To 9 .
5. 2/1 O2 SENSOR HEATER OPERATION Turn the ignition off. NOTE: Wait a minimum of 10 minutes to allow the O2 Sensor to cool down before continuing the test. Allow the O2 Sensor voltage to stabilize at 5.0 Volts. NOTE: Perform the following test on all O2 Sensors. Ignition on, engine not running. With the scan tool, actuate the 2/1 O2 Heater Test. Using the scan tool, monitor 2/1 O2 Sensor voltage for at least two minutes. Does the voltage stay above 4.5 Volts? Yes Verify that there is good pin to terminal contact in the O2 Sensor and Powertrain Control Module connectors. Replace the 2/1 O2 Sensor if no problems were found with the connectors. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 6 .
6. MAP SENSOR OPERATION Ignition on, engine not running. With the scan tool, read the Barometric Pressure. NOTE: The Barometric Pressure should be approximately equal to the actual barometric pressure. If necessary, compare the value to the value of a known good vehicle of a similar make and model. Turn the ignition off. Connect a Vacuum Gauge to a Manifold Vacuum source. Start the engine. Allow the engine to idle. NOTE: If engine will not idle, maintain a constant RPM above idle. Using the scan tool, read the MAP Sensor vacuum value. Is the scan tool reading for MAP Vacuum within 1" of Hg on the Vacuum Gauge reading and is the Barometric Pressure reading of the vehicle the approximately the same as actual Barometric Pressure? Yes Go To 7 . No Verify that there is good pin to terminal contact in the MAP Sensor and Powertrain Control Module connectors. Replace the MAP Sensor if no problems were found with the connectors. Refer to «SENSOR, MANIFOLD AIR PRESSURE (MAP), REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. ECT SENSOR OPERATION NOTE: For this test to be valid, the thermostat must be operating correctly. NOTE: This test works best if performed on a cold engine (cold soak). Ignition on, engine not running. Using the scan tool, read the Engine Coolant Temperature (ECT) Sensor value. If the engine was allowed to sit overnight (cold soak), the temperature value should be a sensible value that is somewhere close to the ambient temperature. NOTE: If engine coolant temperature is above 82° C (180° F), allow the engine to cool until 65° C (150° F) is reached. Start the Engine. During engine warm-up, monitor the ECT Sensor value. The temperature value change should be a smooth transition from start up to normal operating temperature 82° C (180° F). The value should reach at least 82° C (180° F). Did the ECT value increase smoothly and did it reach at least 82° C (180° F)? Yes Go To 8 . No Verify that there is good pin to terminal contact in the ECT Sensor and Powertrain Control Module connectors. Replace the Engine Coolant Temperature Sensor if no problems were found with the connectors. Refer to «SENSOR, COOLANT TEMPERATURE, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/accessory-drive-belts/#engine-cooling-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
8. ENGINE MECHANICAL Turn the ignition off. Check for any of the following conditions/mechanical problems. AIR INDUCTION SYSTEM - must be free from leaks. ENGINE VACUUM - must be at least 13 inches in neutral ENGINE VALVE TIMING - must be within specifications ENGINE COMPRESSION - must be within specifications ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks. ENGINE PCV SYSTEM - must flow freely TORQUE CONVERTER STALL SPEED - must be within specifications POWER BRAKE BOOSTER - no internal vacuum leaks FUEL - must be free of contamination FUEL INJECTOR - plugged or restricted injector; control wire not connected to correct injector Are there any engine mechanical problems? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 12 .
9. O2 SENSOR Ignition on, engine not running. Disconnect the 2/1 O2 Sensor harness connector. Using the scan tool, monitor the 2/1 O2 Sensor voltage. O2 Sensor voltage should read between 4.1 and 5.0 Volts on the scan tool with the connector disconnected. Connect a jumper wire between the (K43) O2 Sensor 2/1 Signal circuit and the (K902) O2 Return Upstream circuit in the O2 Sensor harness connector. NOTE: The voltage should drop from between 4.1 and 5.0 Volts to 2.5 Volts with the jumper wire in place. Did the O2 Sensor voltage change from between 4.1 and 5.0 Volts to 2.5 Volts when the jumper wire was installed? Yes Verify that there is good pin to terminal contact in the O2 Sensor and Powertrain Control Module connectors. Replace the 2/1 O2 Sensor if no problems were found with the connectors. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 10 . NOTE: Remove the jumper wire before continuing.
10. O2 SENSOR SIGNAL CIRCUIT Using the scan tool, monitor all the O2 Sensor voltage reading with the jumper wire removed. NOTE: The scan tool will display all O2 Sensor voltage readings approximately 5.0 Volts when only one O2 Sensor's Signal circuit is shorted to voltage. NOTE: The scan tool will display one O2 Sensor voltage close to zero and the others will read lower than normal when one O2 Sensor Signal circuit contains excessive resistance. Is the voltage between 4.1 and 5.0 Volts? Yes Go To 11 . No Check all the O2 Signal circuits for an open, short to ground or short to voltage. Inspect the O2 Sensor connector and the PCM harness connector. If OK, replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
11. (K902) O2 RETURN UPSTREAM CIRCUIT Measure the voltage on the (K902) O2 Return Upstream circuit in the O2 Sensor harness connector. Is the voltage at 2.5 Volts? Yes Go To 12 . No Check the (K902) O2 Return Upstream circuit for a short to ground, open or short to voltage. Inspect the O2 Sensor connector and the PCM harness connector. If OK, replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
12. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Sensors and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the 1/1 O2 Sensor and Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
13. RESTRICTED FUEL SUPPLY LINE WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Raise vehicle on hoist and disconnect the fuel pressure line at the fuel pump module. Install Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) between the fuel supply line and the fuel pump module. Ignition on, engine not running. Using the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Is the fuel pressure within specification? Yes Repair or replace fuel supply line as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 14 . CAUTION: Stop All Actuations.
14. FUEL PUMP INLET STRAINER WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Turn the ignition off. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Is the Fuel Inlet Strainer plugged? Yes Replace the Fuel Pump Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
15. FUEL PUMP MODULE Repair Verify that there is good pin to terminal contact in the Fuel Pump Module and Powertrain Control Module connectors. Replace the Fuel Pump Module if no problems were found with the connectors. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0175-FUEL SYSTEM 2/1 RICH

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fuel feedback system will maintain a stoiciometric fuel/air mixture, 14.7:1, by modifying the injector pulsewidth according to the oxygen content of the exhaust gas. The PCM makes short term and long term fuel corrections to maintain stoiciometric fuel/air ratio for best catalytic converter efficiency. Short term fuel correction is based on upstream O2 sensor output and is designed for quick engine response. The long term fuel correction compensated for variations in the engine specifications, sensor tolerances and component aging and is designed to correct rich and lean conditions over a longer period of time.

With the engine running in closed loop mode, the ambient/battery temperature above -6.7°C (20°F) and altitude below 2590.8 m (8500 ft).

If the Powertrain Control Module (PCM) multiplies short term compensation by long term adaptive and a purge fuel multiplier and the result is below a certain value for 30 seconds over two trips, a freeze frame is stored, the MIL illuminates and a trouble code is stored. Two Trip Fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) NOTE: Check for contaminates that may have damaged an O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant. Start the engine. Allow the engine to reach normal operating temperature. With the scan tool, read DTCs. NOTE: It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data. Is the DTC Active or Pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. CHECKING FUEL PRESSURE WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) to the fuel rail. Ignition on, engine not running. Using the scan tool, actuate the Fuel System test and observe the fuel pressure gauge. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Turn the ignition off. Choose a conclusion that best matches your fuel pressure reading. Within Specification Go To 3 . Above Specification Replace the fuel filter/pressure regulator. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . CAUTION: Before Proceeding Stop All Actuations.
3. O2 SENSOR OPERATION Start the engine. Allow the engine to reach normal operating temperature. NOTE: If one of the O2 Sensors Signal or Return circuit is shorted to ground or voltage, all the other O2 Sensor voltage readings will be affected. NOTE: After the repairs have been made, verify proper O2 Sensor operation. If all the O2 Sensor voltage readings have not returned to normal, follow the diagnostic procedure for the remaining O2 Sensors. Using the scan tool, monitor the 2/1 O2 Sensor voltage reading. Is the voltage switching between 2.5 and 3.4 Volts? Yes Go To 4 . No Go To 9 .
4. 2/1 O2 SENSOR HEATER OPERATION Turn the ignition off. NOTE: Wait a minimum of 10 minutes to allow the O2 Sensor to cool down before continuing the test. Allow the O2 Sensor voltage to stabilize at 5.0 Volts. Ignition on, engine not running. Using the scan tool, perform the 2/1 O2 Heater Test for each O2 Sensor. Using the scan tool, monitor the 2/1 O2 Sensor voltage while performing the Heater test for at least two minutes. Does the voltage stay above 4.5 Volts for each Sensor? Yes Verify that there is good pin to terminal contact in the O2 Sensor and Powertrain Control Module connectors. Replace the 2/1 O2 Sensor if no problems were found with the connectors. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 .
5. MAP SENSOR OPERATION Ignition on, engine not running. With the scan tool, read the Barometric Pressure. NOTE: The Barometric Pressure should be approximately equal to the actual barometric pressure. If necessary, compare the Barometric Pressure value of this vehicle to the value of a known good vehicle of a similar make and model. Turn the ignition off. Connect a Vacuum Gauge to a Manifold Vacuum source. Start the engine. Allow the engine to idle. NOTE: If engine will not idle, maintain a constant RPM above idle. Using the scan tool, read the MAP Sensor vacuum value. Is the scan tool reading for MAP Vacuum within 1" of Hg on the Vacuum Gauge reading and is the Barometric Pressure reading of the vehicle the approximately the same as actual Barometric Pressure? Yes Go To 6 . No Verify that there is good pin to terminal contact in the MAP Sensor and Powertrain Control Module connectors. Replace the MAP Sensor if no problems were found with the connectors. Refer to «SENSOR, MANIFOLD AIR PRESSURE (MAP), REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . NOTE: Remove the vacuum gauge before continuing.
6. ECT SENSOR OPERATION NOTE: For this test to be valid, the thermostat must be operating correctly. NOTE: This test works best if performed on a cold engine (cold soak). Ignition on, engine not running. Using the scan tool, read the Engine Coolant Temperature Sensor value. If the engine was allowed to sit overnight (cold soak), the temperature value should be a sensible value that is somewhere close to the ambient temperature. NOTE: If engine coolant temperature is above 82° C (180° F), allow the engine to cool until 65° C (150° F) is reached. Start the Engine. During engine warm-up, monitor the Engine Coolant Temperature value. The temp value change should be a smooth transition from start up to normal operating temp 82° C (180° F). The value should reach at least 82° C (180° F). Did the ECT value increase smoothly and reach at least 82° C (180° F)? Yes Go To 7 . No Verify that there is good pin to terminal contact in the ECT Sensor and Powertrain Control Module connectors. Replace the Engine Coolant Temperature Sensor if no problems were found with the connectors. Refer to «SENSOR, COOLANT TEMPERATURE, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/accessory-drive-belts/#engine-cooling-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. EVAP PURGE SOLENOID OPERATION Turn the ignition off. Disconnect the hoses at the EVAP Purge Solenoid. Using a hand vacuum pump, apply 10 inches of vacuum to the EVAP Purge Solenoid vacuum source port on the component side. Did the EVAP Purge Solenoid hold vacuum? Yes Go To 8 . No Verify that there is good pin to terminal contact in the EVAP Purge Solenoid and Powertrain Control Module connectors. Replace the EVAP Purge Solenoid if no problems were found with the connectors. Refer to «SOLENOID, EVAPORATIVE EMISSIONS PURGE, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#emissions-control) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . NOTE: Connect the vacuum hoses before continuing.
8. ENGINE MECHANICAL Turn the ignition off. Check for any of the following conditions/mechanical problems: AIR INDUCTION SYSTEM - must be free from leaks. ENGINE VACUUM - must be at least 13 inches in neutral ENGINE VALVE TIMING - must be within specifications ENGINE COMPRESSION - must be within specifications ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks. ENGINE PCV SYSTEM - must flow freely TORQUE CONVERTER STALL SPEED - must be within specifications POWER BRAKE BOOSTER - no internal vacuum leaks FUEL - must be free of contamination FUEL INJECTOR - plugged or restricted injector; control wire not connected to correct injector Are there any engine mechanical problems? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 12 .
9. 2/1 O2 SENSOR Ignition on, engine not running. Disconnect the 2/1 O2 Sensor harness connector. Using the scan tool, monitor the 2/1 O2 Sensor voltage. O2 Sensor voltage should read between 4.1 and 5.0 Volts on the scan tool with the connector disconnected. Connect a jumper wire between the (K43) O2 Sensor 2/1 Signal circuit and the (K902) O2 Return Upstream circuit in the O2 Sensor harness connector. NOTE: The voltage should drop from between 4.1 and 5.0 Volts down to 2.5 Volts with the jumper wire connected. Did the O2 Sensor voltage drop from between 4.1 and 5.0 Volts to 2.5 Volts when the jumper wire was installed? Yes Verify that there is good pin to terminal contact in the O2 Sensor and Powertrain Control Module connectors. Replace the 2/1 O2 Sensor if no problems were found with the connectors. Refer to «SENSOR, OXYGEN, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 10 . NOTE: Remove the jumper wire before continuing.
10. O2 SENSOR SIGNAL CIRCUIT Measure the voltage on the (K43) O2 Sensor 2/1 Signal circuit in the O2 Sensor harness connector. Is the voltage between 4.1 and 5.0 Volts? Yes Go To 11 . No Check the (K43) O2 Sensor 2/1 Signal circuit for damage, short to ground, open or short to voltage. Inspect the O2 Sensor connector and the PCM harness connector. If OK, replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
11. (K902) O2 SENSOR RETURN UPSTREAM CIRCUIT Measure the voltage on the (K902) O2 Return Upstream circuit in the O2 Sensor harness connector. Is the voltage at 2.5 Volts? Yes Go To 12 . No Check the (K902) O2 Return Upstream circuit for damage, short to ground, open or short to voltage. Inspect the O2 Sensor connector and the PCM harness connector. If OK, replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . NOTE: Turn the ignition off before continuing.
12. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Sensors and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the 1/1 O2 Sensor and Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

Scheme 134

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The Engine Oil Temperature (EOT) sensor is a variable resistor that measures the temperature of the engine oil. The Powertrain Control Module (PCM) supplies a 5 Volt reference and a ground to the sensors low reference signal circuit. When the oil temperature is low, the sensor resistance is high. When the oil temperature is high, the sensor resistance is low.

With engine off time greater than 480 minutes and ambient temperature greater than -7° C (19.4° F).

After a calibrated amount of cool down time, the Powertrain Control Module (PCM) compares the AAT, ECT and IAT Sensor values. If the general temperature rationality passes, the PCM compares the Oil Temperature Sensor value to a threshold based on the other temp sensor values. If the difference is greater than a calibrated value, the diagnostic fails.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 135

Scheme 136

Scheme 137

1. ACTIVE DTC Turn the ignition off. If possible, allow the vehicle to sit with the ignition off for more than 480 minutes in an environment where the temperature is consistent and above -7° C (19.4° F). Test drive the vehicle. The vehicle must exceed 48 km/h (30 mph) during the test drive. Do not cycle the ignition off when the test drive is completed. With the scan tool, select View DTCs. Is the status Active or Pending for this DTC? Yes Go To 3 . No Go To 2 .
2. ENGINE OIL TEMPERATURE Turn the ignition off. Allow the vehicle to sit with the ignition off in an environment where the temperature is consistent and above -7° C (19.4° F) until the engine coolant temperature is equal to ambient temperature. Turn the ignition on. With the scan tool, compare the EOT sensor value to the AAT, ECT and IAT sensor values. Is the Engine Oil Temperature Sensor value within 10° C (18° F) of the other sensor values? Yes Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. ENGINE OIL TEMPERATURE SENSOR VOLTAGE Turn the ignition off. Disconnect the Engine Oil Temperature Sensor harness connector. Turn the ignition on. With the scan tool, read the Engine Oil Temperature Sensor voltage. NOTE: The sensor voltage should be approximately 5.0 Volts (plus or minus.1 of a Volt) with the connector disconnected. Does the scan tool display the voltage as described above? Yes Go To 4 . No Go To 5 .
4. ENGINE OIL TEMPERATURE SENSOR Turn the ignition on. With the scan tool, read the Engine Oil Temperature Sensor voltage. Connect a jumper wire between the (G24) EOT Signal circuit and the (K900) Sensor Ground circuit in the Engine Oil Temperature Sensor harness connector. NOTE: The sensor voltage should be approximately 0.0 Volts (plus or minus.1 of a Volt) with the jumper wire in place. Does the scan tool display the voltage as described above? Yes Verify that there is good pin to terminal contact in the Engine Oil Temperature Sensor and Powertrain Control Module connectors. Replace the Engine Oil Temperature Sensor if no problems were found with the connectors. Refer to «SENSOR, OIL TEMPERATURE, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/mechanical/#36l-engine-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 . NOTE: Remove the jumper wire before continuing.
5. (G24) ENGINE OIL TEMP SIGNAL CIRCUIT OPEN Turn the ignition off. Disconnect the C2 and C3 PCM harness connectors. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (G24) Engine Oil Temp Signal circuit from the Engine Oil Temp Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open or excessive resistance in the (G24) Engine Oil Temp Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. (K900) SENSOR GROUND CIRCUIT OPEN CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) along with the Adapter (special tool #8815-1, PCM Pinout Box Adapter) to perform the diagnosis. Measure the resistance of the (K900) Sensor ground circuit from the Engine Oil Temp Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 7 . No Repair the open or excessive resistance in the (G24) Engine Oil Temp Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Engine Oil Temperature Sensor and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the EOT Sensor and Control Module connectors. Perform any Technical Service Bulletins (TSBs) that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0197-ENGINE OIL TEMPERATURE SENSOR CIRCUIT LOW

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

Thoery of operation

The oil temperature sensor is a variable resistor that measures the temperature of the engine oil. The Powertrain Control Module (PCM) supplies a 5 Volt reference and a ground to the sensors low reference signal circuit. When the oil temperature is low, the sensor resistance is high. When the oil temperature is high, the sensor resistance is low.

With the ignition on. Battery voltage greater than 10.4 Volts.

The Engine Oil Temperature sensor circuit voltage at the Powertrain Control Module (PCM) is less than the calibrated amount. One Trip Fault. Three good trips to clear the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 138

Scheme 139

1. ACTIVE DTC Start the engine and allow it to reach normal operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Diagnose and repair any system voltage DTCs before continuing with this test. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. ENGINE OIL TEMPERATURE SENSOR Turn the ignition off. Disconnect the Engine Oil Temp Sensor harness connector. Ignition on, engine not running. With the scan tool, read Engine Oil Temp voltage. NOTE: The sensor voltage should be approximately 5.0 Volts (plus or minus.1 of a Volt) with the connector disconnected. Does the scan tool display the voltage as described above? Yes Verify that there is good pin to terminal contact in the Engine Oil Temperature Sensor and Powertrain Control Module connectors. Replace the Engine Oil Temperature Sensor if no problems were found with the connectors. Refer to «SENSOR, OIL TEMPERATURE, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/mechanical/#36l-engine-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. (G24) ENGINE OIL TEMP SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT Turn the ignition off. Disconnect PCM C3 and C2 harness connectors. Measure the resistance between the (K900) Sensor ground circuit and the (G24) Engine Oil Temp Signal circuit in the Engine Oil Temp Sensor harness connector. Is the resistance below 5.0 Ohms? Yes Repair the short to between the (K900) Sensor ground circuit and the (G24) Engine Oil Temp Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (G24) ENGINE OIL TEMP SIGNAL CIRCUIT SHORTED GROUND Measure the resistance between ground and the (G24) Engine Oil Temp Signal circuit in the Engine Oil Temp Sensor harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (G24) Engine Oil Temp Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 .
5. (G24) ENGINE OIL TEMPERATURE SIGNAL CIRCUIT OPEN CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (G24) Engine Oil Temperature Signal circuit between the Engine Oil Temperature Sensor harness connector and the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open or excessive resistance in the (G24) EOT Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Engine Oil Temperature Sensor and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Sensor and Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0198-ENGINE OIL TEMPERATURE SENSOR CIRCUIT HIGH

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The oil temperature sensor is a variable resistor that measures the temperature of the engine oil. The Powertrain Control Module (PCM) supplies a 5 Volt reference and a ground to the sensors low reference signal circuit. When the oil temperature is low, the sensor resistance is high. When the oil temperature is high, the sensor resistance is low.

With the ignition on. Battery voltage greater than 10.4 Volts.

The Engine Oil Temperature Sensor circuit voltage at the Powertrain Control Module (PCM) is greater than the calibrated amount. One Trip Fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 140

1. ACTIVE DTC Start the engine and allow it to reach normal operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Diagnose and repair any system voltage DTCs before continuing with this test. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. ENGINE OIL TEMP SENSOR With the scan tool, clear the DTC. Turn the ignition off. Disconnect the Engine Oil Temp Sensor harness connector. Connect a jumper wire between the (G24) Engine Oil Temp Signal circuit and the (K900) Sensor ground circuit in the Engine Oil Temp Sensor harness connector. Ignition on, engine not running. NOTE: The sensor voltage should be approximately 0.0 Volts (plus or minus.1 of a Volt) with the jumper wire in place. Does the scan tool display the voltage as described above? Yes Verify that there is good pin to terminal contact in the EOT Sensor and Control Module connectors. Replace the Engine Oil Temperature Sensor if no problems were found with the connectors. Refer to «SENSOR, OIL TEMPERATURE, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/mechanical/#36l-engine-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 . NOTE: Remove the jumper wire before continuing.
3. (G24) ENGINE OIL TEMP SIGNAL CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Disconnect the C2 and C3 PCM harness connectors. Ignition on, engine not running. Measure the voltage on the (G24) Engine Oil Temp Signal circuit in the Engine Oil Temp Sensor harness connector. Is there any voltage present? Yes Repair the short to voltage in the (G24) Engine Oil Temp Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (G24) ENGINE OIL TEMP SIGNAL CIRCUIT OPEN Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (G24) Engine Oil Temp Signal circuit from the Engine Oil Temp Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 5 . No Repair the open or excessive resistance in the (G24) Engine Oil Temp Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K900) SENSOR GROUND CIRCUIT OPEN CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K900) Sensor ground circuit from the Engine Oil Temp Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open or excessive resistance in the (K900) Sensor ground circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Engine Oil Temperature Sensor and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Sensor and Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

Scheme 141

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fueling strategy for the Powertrain control Module (PCM) requires potentially three fuel pulses per cylinder per cycle. The first pulse is delivered starting at a programmed angle soon after the intake valve closes, for specified time duration. This is for two reasons, one to prevent any fuel from this pulse being delivered in the previous cycle and second to allow fueling to begin as early as possible in the current cycle. The second pulse is delivered for a specified time and is set to end at a programmed angle. The pulse must not extend past the end angle. There can be a separate value for each cylinder under the same operating conditions. This is done for two reasons, one to prevent any fuel from this pulse being delivered during the intake/exhaust valve overlap period, which tends to cause elevated emission levels. Also, allowing fuel to enter each cylinder at a slightly different angle tends to reduce any fuel pressure standing waves in the fuel rail. If the desired total fuel pulse-width increases, a third fuel pulse must be delivered. The third pulse, if necessary, is delivered for a specified time and must end at a programmed angle before the valve closes again. The third pulse in the cycle is controlled by its ending angle. This is also for two reasons, one to prevent any fuel from this pulse being delivered in the next cycle and second to allow fueling to end as late as possible in the current cycle. At high engine speeds, one or more of the pulses may be dropped from the fueling strategy.

With battery voltage greater than 10 Volts. Auto Shutdown Relay energized. Engine speed less than 3000 RPM.

The Powertrain Control Module (PCM) monitors the continuity of the injector circuits as well as the voltage spike created by the collapse of the magnetic field in the injector coil. Any condition that reduces the maximum current flow or the magnitude of the voltage spike can cause this DTC to set.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 142

Scheme 143

Scheme 144

Scheme 145

1. DTC IS ACTIVE Turn the ignition on. With the scan tool, select View DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to reach operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. FUEL INJECTOR 1 CIRCUIT RESISTANCE Turn the ignition off. Disconnect the C2 PCM harness connector. Remove the ASD Relay. NOTE: The resistance of the circuit will vary according to the temperature of the injector coil. Use the table below to determine the resistance range of the injector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the Fuel Injector 1 circuit from the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) and the ASD Relay. Fuel Injector Coil Resistance Based on Engine Temperature Temperature Resistance -20° C (-4° F) 10 Ohms (+/-.6 of an Ohm) 20° C (68° F) 12 Ohms (+/-.6 of an Ohm) 60° C (140° F) 14 Ohms (+/-.6 of an Ohm) 100° C (212° F) 16 Ohms (+/-.6 of an Ohm) Is the resistance of the injector within the specified range? Yes Go To 7 . No Go To 3 .
3. FUEL INJECTOR 1 WIRING AND CONNECTOR INSPECTION Turn the ignition off. Verify that the Fuel Injector 1 is properly connected to the injector. Disconnect the Fuel Injector 1 connector and Inspect the terminals for any condition that would result in a poor connection. Using the wiring diagram/schematic as a guide, inspect the Fuel Injector 1 wiring and connector. Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (F342) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE Install the ASD Relay. Connect the C2 PCM harness connector. Turn the ignition on. With the scan tool, actuate the Auto Shutdown (ASD) Relay Control State. Using a 12-volt test light connected to ground, check the (F342) ASD Relay Output circuit in the Fuel Injector 1 harness connector. NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery. Is the test light illuminated and bright? Yes Go To 5 . No Repair the excessive resistance or short to ground in the (F342) ASD Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K11) INJECTOR 1 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K11) Injector 1 Control circuit between the Fuel Injector 1 harness connector and the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the excessive resistance or open in the (K11) Injector 1 Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL INJECTOR 1 Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 1 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the Fuel Injector 1 in accordance with the Service Information. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K11) INJECTOR 1 CONTROL CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C2 PCM harness connector. Measure the resistance between ground and the (K11) Injector 1 Control circuit in the Fuel Injector 1 harness connector. Is the resistance above 100 Ohms? Yes Go To 8 . No Repair the (K11) Injector 1 Control circuit for a short to ground. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 1 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

Scheme 146

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fueling strategy for the Powertrain Control Module (PCM) requires potentially three fuel pulses per cylinder per cycle. The first pulse is delivered starting at a programmed angle soon after the intake valve closes, for specified time duration. This is for two reasons, one to prevent any fuel from this pulse being delivered in the previous cycle and second to allow fueling to begin as early as possible in the current cycle. The second pulse is delivered for a specified time and is set to end at a programmed angle. The pulse must not extend past the end angle. There can be a separate value for each cylinder under the same operating conditions. This is done for two reasons, one to prevent any fuel from this pulse being delivered during the intake/exhaust valve overlap period, which tends to cause elevated emission levels. Also, allowing fuel to enter each cylinder at a slightly different angle tends to reduce any fuel pressure standing waves in the fuel rail. If the desired total fuel pulse-width increases, a third fuel pulse must be delivered. The third pulse, if necessary, is delivered for a specified time and must end at a programmed angle before the valve closes again. The third pulse in the cycle is controlled by its ending angle. This is also for two reasons, one to prevent any fuel from this pulse being delivered in the next cycle and second to allow fueling to end as late as possible in the current cycle. At high engine speeds, one or more of the pulses may be dropped from the fueling strategy.

With battery voltage greater than 10 Volts. Auto Shutdown Relay energized. Engine speed less than 3000 RPM.

The Powertrain Control Module (PCM) monitors the continuity of the injector circuits as well as the voltage spike created by the collapse of the magnetic field in the injector coil. Any condition that reduces the maximum current flow or the magnitude of the voltage spike can cause this DTC to set.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. DTC IS ACTIVE Turn the ignition on. With the scan tool, select View DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to reach operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. FUEL INJECTOR 1 CIRCUIT RESISTANCE Turn the ignition off. Disconnect the C2 PCM harness connector. Remove the ASD Relay. NOTE: The resistance of the circuit will vary according to the temperature of the injector coil. Use the table below to determine the resistance range of the injector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the Fuel Injector 1 circuit from the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) and the ASD Relay. Fuel Injector Coil Resistance Based on Engine Temperature Temperature Resistance -20° C (-4° F) 10 Ohms (+/-.6 of an Ohm) 20° C (68° F) 12 Ohms (+/-.6 of an Ohm) 60° C (140° F) 14 Ohms (+/-.6 of an Ohm) 100° C (212° F) 16 Ohms (+/-.6 of an Ohm) Is the resistance of the injector within the specified range? Yes Go To 7 . No Go To 3 .
3. FUEL INJECTOR 1 WIRING AND CONNECTOR INSPECTION Turn the ignition off. Verify that the Fuel Injector 1 is properly connected to the injector. Disconnect the Fuel Injector 1 connector and Inspect the terminals for any condition that would result in a poor connection. Using the wiring diagram/schematic as a guide, inspect the Fuel Injector 1 wiring and connector. Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (F342) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE Install the ASD Relay. Turn the ignition on. With the scan tool, actuate the Auto Shutdown (ASD) Relay Control State. Using a 12-volt test light connected to ground, check the (F342) ASD Relay Output circuit in the Fuel Injector 1 harness connector. NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery. Is the test light illuminated and bright? Yes Go To 5 . No Repair the excessive resistance or short to ground in the (F342) ASD Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K11) INJECTOR 1 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K11) Injector 1 Control circuit between the Fuel Injector 1 harness connector and the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the excessive resistance in the (K11) Injector 1 Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL INJECTOR 1 Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 1 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the Fuel Injector 1 in accordance with the Service Information. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K11) INJECTOR 1 CONTROL CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C2 PCM harness connector. Measure the resistance between ground and the (K11) Injector 1 Control circuit in the Fuel Injector 1 harness connector. Is the resistance above 100 Ohms? Yes Go To 8 . No Repair the (K11) Injector 1 Control circuit for a short to ground. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 1 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0202-FUEL INJECTOR 2 CIRCUIT - 3.6L

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fueling strategy for the Powertrain Control Module (PCM) requires potentially three fuel pulses per cylinder per cycle. The first pulse is delivered starting at a programmed angle soon after the intake valve closes, for specified time duration. This is for two reasons, one to prevent any fuel from this pulse being delivered in the previous cycle and second to allow fueling to begin as early as possible in the current cycle. The second pulse is delivered for a specified time and is set to end at a programmed angle. The pulse must not extend past the end angle. There can be a separate value for each cylinder under the same operating conditions. This is done for two reasons, one to prevent any fuel from this pulse being delivered during the intake/exhaust valve overlap period, which tends to cause elevated emission levels. Also, allowing fuel to enter each cylinder at a slightly different angle tends to reduce any fuel pressure standing waves in the fuel rail. If the desired total fuel pulse-width increases, a third fuel pulse must be delivered. The third pulse, if necessary, is delivered for a specified time and must end at a programmed angle before the valve closes again. The third pulse in the cycle is controlled by its ending angle. This is also for two reasons, one to prevent any fuel from this pulse being delivered in the next cycle and second to allow fueling to end as late as possible in the current cycle. At high engine speeds, one or more of the pulses may be dropped from the fueling strategy.

With battery voltage greater than 10 Volts. Auto Shutdown Relay energized. Engine speed less than 3000 RPM.

The Powertrain Control Module (PCM) monitors the continuity of the injector circuits as well as the voltage spike created by the collapse of the magnetic field in the injector coil. Any condition that reduces the maximum current flow or the magnitude of the voltage spike can cause this DTC to set.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 147

Scheme 148

Scheme 149

Scheme 150

1. ACTIVE DTC Turn the ignition on. With the scan tool, select View DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to reach operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. FUEL INJECTOR 2 CIRCUIT RESISTANCE Turn the ignition off. Disconnect the C2 PCM harness connector. Remove the ASD Relay. NOTE: The resistance of the circuit will vary according to the temperature of the injector coil. Use the table below to determine the resistance range of the injector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the Fuel Injector 2 circuit from the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) and the ASD Relay connector. Fuel Injector Coil Resistance Based on Engine Temperature Temperature Resistance -20° C (-4° F) 10 Ohms (+/-.6 of an Ohm) 20° C (68° F) 12 Ohms (+/-.6 of an Ohm) 60° C (140° F) 14 Ohms (+/-.6 of an Ohm) 100° C (212° F) 16 Ohms (+/-.6 of an Ohm) Is the resistance of the injector within the specified range? Yes Go To 7 . No Go To 3 .
3. FUEL INJECTOR 2 WIRING AND CONNECTOR INSPECTION Turn the ignition off. Verify that the Fuel Injector 2 is properly connected to the injector. Disconnect the Fuel Injector 2 connector and Inspect the terminals for any condition that would result in a poor connection. Using the wiring diagram/schematic as a guide, inspect the Fuel Injector 2 wiring and connector. Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (F342) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE Turn the ignition on. With the scan tool, actuate the Auto Shutdown (ASD) Relay Control State. Using a 12-volt test light connected to ground, check the (F342) ASD Relay Output circuit in the Fuel Injector 2 harness connector. NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery. Is the test light illuminated and bright? Yes. Go To 5 . No. Repair the excessive resistance or short to ground in the (F342) ASD Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K12) IINJECTOR 2 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K12) Injector Control No. 2 circuit from the Fuel Injector harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open in the (K12) Injector Control No. 2 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL INJECTOR 2 Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 2 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the Fuel Injector 2 in accordance with the Service Information. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K12) INJECTOR CONTROL NO. 2 CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C2 PCM harness connector. Measure the resistance between ground and the (K12) Injector Control No. 2 circuit in the Injector harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K12) Injector Control No. 2 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 2 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0202-FUEL INJECTOR 2 CIRCUIT - 5.7L

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fueling strategy for the Powertrain Control Module (PCM) requires potentially three fuel pulses per cylinder per cycle. The first pulse is delivered starting at a programmed angle soon after the intake valve closes, for specified time duration. This is for two reasons, one to prevent any fuel from this pulse being delivered in the previous cycle and second to allow fueling to begin as early as possible in the current cycle. The second pulse is delivered for a specified time and is set to end at a programmed angle. The pulse must not extend past the end angle. There can be a separate value for each cylinder under the same operating conditions. This is done for two reasons, one to prevent any fuel from this pulse being delivered during the intake/exhaust valve overlap period, which tends to cause elevated emission levels. Also, allowing fuel to enter each cylinder at a slightly different angle tends to reduce any fuel pressure standing waves in the fuel rail. If the desired total fuel pulse-width increases, a third fuel pulse must be delivered. The third pulse, if necessary, is delivered for a specified time and must end at a programmed angle before the valve closes again. The third pulse in the cycle is controlled by its ending angle. This is also for two reasons, one to prevent any fuel from this pulse being delivered in the next cycle and second to allow fueling to end as late as possible in the current cycle. At high engine speeds, one or more of the pulses may be dropped from the fueling strategy.

With battery voltage greater than 10 Volts. Auto Shutdown Relay energized. Engine speed less than 3000 RPM.

The Powertrain Control Module (PCM) monitors the continuity of the injector circuits as well as the voltage spike created by the collapse of the magnetic field in the injector coil. Any condition that reduces the maximum current flow or the magnitude of the voltage spike can cause this DTC to set.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC Turn the ignition on. With the scan tool, select View DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to reach operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. FUEL INJECTOR 2 CIRCUIT RESISTANCE Turn the ignition off. Disconnect the C2 PCM harness connector. Remove the ASD Relay. NOTE: The resistance of the circuit will vary according to the temperature of the injector coil. Use the table below to determine the resistance range of the injector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the Fuel Injector 2 circuit from the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) and the ASD Relay connector. Fuel Injector Coil Resistance Based on Engine Temperature Temperature Resistance -20° C (-4° F) 10 Ohms (+/-.6 of an Ohm) 20° C (68° F) 12 Ohms (+/-.6 of an Ohm) 60° C (140° F) 14 Ohms (+/-.6 of an Ohm) 100° C (212° F) 16 Ohms (+/-.6 of an Ohm) Is the resistance of the injector within the specified range? Yes Go To 7 . No Go To 3 .
3. FUEL INJECTOR 2 WIRING AND CONNECTOR INSPECTION Turn the ignition off. Verify that the Fuel Injector 2 is properly connected to the injector. Disconnect the Fuel Injector 2 connector and Inspect the terminals for any condition that would result in a poor connection. Using the wiring diagram/schematic as a guide, inspect the Fuel Injector 2 wiring and connector. Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (F342) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE Turn the ignition on. With the scan tool, actuate the Auto Shutdown (ASD) Relay Control State. Using a 12-volt test light connected to ground, check the (F342) ASD Relay Output circuit in the Fuel Injector 2 harness connector. NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery. Is the test light illuminated and bright? Yes. Go To 5 . No. Repair the excessive resistance or short to ground in the (F342) ASD Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K12) IINJECTOR 2 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K12) Injector Control No. 2 circuit from the Fuel Injector harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open in the (K12) Injector Control No. 2 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL INJECTOR 2 Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 2 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the Fuel Injector 2 in accordance with the Service Information. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K12) INJECTOR CONTROL NO. 2 CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C2 PCM harness connector. Measure the resistance between ground and the (K12) Injector Control No. 2 circuit in the Injector harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K12) Injector Control No. 2 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 2 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0203-FUEL INJECTOR 3 CIRCUIT - 3.6L

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fueling strategy for the Powertrain Control Module (PCM) requires potentially three fuel pulses per cylinder per cycle. The first pulse is delivered starting at a programmed angle soon after the intake valve closes, for specified time duration. This is for two reasons, one to prevent any fuel from this pulse being delivered in the previous cycle and second to allow fueling to begin as early as possible in the current cycle. The second pulse is delivered for a specified time and is set to end at a programmed angle. The pulse must not extend past the end angle. There can be a separate value for each cylinder under the same operating conditions. This is done for two reasons, one to prevent any fuel from this pulse being delivered during the intake/exhaust valve overlap period, which tends to cause elevated emission levels. Also, allowing fuel to enter each cylinder at a slightly different angle tends to reduce any fuel pressure standing waves in the fuel rail. If the desired total fuel pulse-width increases, a third fuel pulse must be delivered. The third pulse, if necessary, is delivered for a specified time and must end at a programmed angle before the valve closes again. The third pulse in the cycle is controlled by its ending angle. This is also for two reasons, one to prevent any fuel from this pulse being delivered in the next cycle and second to allow fueling to end as late as possible in the current cycle. At high engine speeds, one or more of the pulses may be dropped from the fueling strategy.

With battery voltage greater than 10 Volts. Auto Shutdown Relay energized. Engine speed less than 3000 RPM.

The Powertrain Control Module (PCM) monitors the continuity of the injector circuits as well as the voltage spike created by the collapse of the magnetic field in the injector coil. Any condition that reduces the maximum current flow or the magnitude of the voltage spike can cause this DTC to set.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 151

Scheme 152

Scheme 153

Scheme 154

1. ACTIVE DTC Turn the ignition on. With the scan tool, select View DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to reach operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. FUEL INJECTOR 3 CIRCUIT RESISTANCE Turn the ignition off. Disconnect the C2 PCM harness connector. Remove the ASD Relay. NOTE: The resistance of the circuit will vary according to the temperature of the injector coil. Use the table below to determine the resistance range of the injector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the Fuel Injector 3 circuit from the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) and the ASD Relay connector. Fuel Injector Coil Resistance Based on Engine Temperature Temperature Resistance -20° C (-4° F) 10 Ohms (+/-.6 of an Ohm) 20° C (68° F) 12 Ohms (+/-.6 of an Ohm) 60° C (140° F) 14 Ohms (+/-.6 of an Ohm) 100° C (212° F) 16 Ohms (+/-.6 of an Ohm) Is the resistance of the injector within the specified range? Yes Go To 7 . No Go To 3 .
3. FUEL INJECTOR 3 WIRING AND CONNECTOR INSPECTION Turn the ignition off. Verify that the Fuel Injector 3 is properly connected to the injector. Disconnect the Fuel Injector 3 connector and Inspect the terminals for any condition that would result in a poor connection. Using the wiring diagram/schematic as a guide, inspect the Fuel Injector 3 wiring and connector. Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (F342) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE Install the ASD Relay. Turn the ignition on. With the scan tool, actuate the Auto Shutdown (ASD) Relay Control State. Using a 12-volt test light connected to ground, check the (F342) ASD Relay Output circuit in the Fuel Injector 3 harness connector. NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery. Is the test light illuminated and bright? Yes. Go To 5 . No. Repair the excessive resistance or short to ground in the (F342) ASD Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K13) INJECTOR 3 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K13) Injector Control No. 3 circuit from the Fuel Injector harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open in the (K13) Injector Control No. 3 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL INJECTOR 3 Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 3 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the Fuel Injector 3 in accordance with the Service Information. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K13) INJECTOR CONTROL NO. 3 CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C2 PCM harness connector. Measure the resistance between ground and the (K13) Injector Control No. 3 circuit in the Injector harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K13) Injector Control No. 3 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 3 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0203-FUEL INJECTOR 3 CIRCUIT - 5.7L

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fueling strategy for the Powertrain Control Module (PCM) requires potentially three fuel pulses per cylinder per cycle. The first pulse is delivered starting at a programmed angle soon after the intake valve closes, for specified time duration. This is for two reasons, one to prevent any fuel from this pulse being delivered in the previous cycle and second to allow fueling to begin as early as possible in the current cycle. The second pulse is delivered for a specified time and is set to end at a programmed angle. The pulse must not extend past the end angle. There can be a separate value for each cylinder under the same operating conditions. This is done for two reasons, one to prevent any fuel from this pulse being delivered during the intake/exhaust valve overlap period, which tends to cause elevated emission levels. Also, allowing fuel to enter each cylinder at a slightly different angle tends to reduce any fuel pressure standing waves in the fuel rail. If the desired total fuel pulse-width increases, a third fuel pulse must be delivered. The third pulse, if necessary, is delivered for a specified time and must end at a programmed angle before the valve closes again. The third pulse in the cycle is controlled by its ending angle. This is also for two reasons, one to prevent any fuel from this pulse being delivered in the next cycle and second to allow fueling to end as late as possible in the current cycle. At high engine speeds, one or more of the pulses may be dropped from the fueling strategy.

With battery voltage greater than 10 Volts. Auto Shutdown Relay energized. Engine speed less than 3000 RPM.

The Powertrain Control Module (PCM) monitors the continuity of the injector circuits as well as the voltage spike created by the collapse of the magnetic field in the injector coil. Any condition that reduces the maximum current flow or the magnitude of the voltage spike can cause this DTC to set.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC Turn the ignition on. With the scan tool, select View DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to reach operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. FUEL INJECTOR 3 CIRCUIT RESISTANCE Turn the ignition off. Disconnect the C2 PCM harness connector. Remove the ASD Relay. NOTE: The resistance of the circuit will vary according to the temperature of the injector coil. Use the table below to determine the resistance range of the injector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the Fuel Injector 3 circuit from the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) and the ASD Relay connector. Fuel Injector Coil Resistance Based on Engine Temperature Temperature Resistance -20° C (-4° F) 10 Ohms (+/-.6 of an Ohm) 20° C (68° F) 12 Ohms (+/-.6 of an Ohm) 60° C (140° F) 14 Ohms (+/-.6 of an Ohm) 100° C (212° F) 16 Ohms (+/-.6 of an Ohm) Is the resistance of the injector within the specified range? Yes Go To 7 . No Go To 3 .
3. FUEL INJECTOR 3 WIRING AND CONNECTOR INSPECTION Turn the ignition off. Verify that the Fuel Injector 3 is properly connected to the injector. Disconnect the Fuel Injector 3 connector and Inspect the terminals for any condition that would result in a poor connection. Using the wiring diagram/schematic as a guide, inspect the Fuel Injector 3 wiring and connector. Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (F342) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE Install the ASD Relay. Turn the ignition on. With the scan tool, actuate the Auto Shutdown (ASD) Relay Control State. Using a 12-volt test light connected to ground, check the (F342) ASD Relay Output circuit in the Fuel Injector 3 harness connector. NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery. Is the test light illuminated and bright? Yes. Go To 5 . No. Repair the excessive resistance or short to ground in the (F342) ASD Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K13) INJECTOR 3 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K13) Injector Control No. 3 circuit from the Fuel Injector harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open in the (K13) Injector Control No. 3 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL INJECTOR 3 Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 3 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the Fuel Injector 3 in accordance with the Service Information. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K13) INJECTOR CONTROL NO. 3 CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C2 PCM harness connector. Measure the resistance between ground and the (K13) Injector Control No. 3 circuit in the Injector harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K13) Injector Control No. 3 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 3 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0204-FUEL INJECTOR 4 CIRCUIT - 3.6L

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fueling strategy for Powertrain Control Module (PCM) requires potentially three fuel pulses per cylinder per cycle. The first pulse is delivered starting at a programmed angle soon after the intake valve closes, for specified time duration. This is for two reasons, one to prevent any fuel from this pulse being delivered in the previous cycle and second to allow fueling to begin as early as possible in the current cycle. The second pulse is delivered for a specified time and is set to end at a programmed angle. The pulse must not extend past the end angle. There can be a separate value for each cylinder under the same operating conditions. This is done for two reasons, one to prevent any fuel from this pulse being delivered during the intake/exhaust valve overlap period, which tends to cause elevated emission levels. Also, allowing fuel to enter each cylinder at a slightly different angle tends to reduce any fuel pressure standing waves in the fuel rail. If the desired total fuel pulse-width increases, a third fuel pulse must be delivered. The third pulse, if necessary, is delivered for a specified time and must end at a programmed angle before the valve closes again. The third pulse in the cycle is controlled by its ending angle. This is also for two reasons, one to prevent any fuel from this pulse being delivered in the next cycle and second to allow fueling to end as late as possible in the current cycle. At high engine speeds, one or more of the pulses may be dropped from the fueling strategy.

With battery voltage greater than 10 Volts. Auto Shutdown Relay energized. Engine speed less than 3000 RPM.

The Powertrain Control Module (PCM) monitors the continuity of the injector circuits as well as the voltage spike created by the collapse of the magnetic field in the injector coil. Any condition that reduces the maximum current flow or the magnitude of the voltage spike can cause this DTC to set.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 155

Scheme 156

Scheme 157

Scheme 158

1. ACTIVE DTC Turn the ignition on. With the scan tool, select View DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to reach operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. FUEL INJECTOR 4 CIRCUIT RESISTANCE Turn the ignition off. Disconnect the C2 PCM harness connector. Remove the ASD Relay. NOTE: The resistance of the circuit will vary according to the temperature of the injector coil. Use the table below to determine the resistance range of the injector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the Fuel Injector 4 circuit from the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) and the ASD Relay connector. Fuel Injector Coil Resistance Based on Engine Temperature Temperature Resistance -20° C (-4° F) 10 Ohms (+/-.6 of an Ohm) 20° C (68° F) 12 Ohms (+/-.6 of an Ohm) 60° C (140° F) 14 Ohms (+/-.6 of an Ohm) 100° C (212° F) 16 Ohms (+/-.6 of an Ohm) Is the resistance of the injector within the specified range? Yes Go To 7 . No Go To 3 .
3. FUEL INJECTOR 4 WIRING AND CONNECTOR INSPECTION Turn the ignition off. Verify that the Fuel Injector 4 is properly connected to the injector. Disconnect the Fuel Injector 4 connector and Inspect the terminals for any condition that would result in a poor connection. Using the wiring diagram/schematic as a guide, inspect the Fuel Injector 4 wiring and connector. Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (F342) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE Install the ASD Relay. Turn the ignition on. With the scan tool, actuate the Auto Shutdown (ASD) Relay Control State. Using a 12-volt test light connected to ground, check the (F342) ASD Relay Output circuit in the Fuel Injector 4 harness connector. NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery. Is the test light illuminated and bright? Yes. Go To 5 . No. Repair the excessive resistance or short to ground in the (F342) ASD Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K14) INJECTOR 4 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K14) Injector Control No. 4 circuit from the Fuel Injector harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open in the (K14) Injector Control No. 4 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL INJECTOR 4 Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 4 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the Fuel Injector 4 in accordance with the Service Information. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K14) INJECTOR CONTROL NO. 4 CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C2 PCM harness connector. Measure the resistance between ground and the (K14) Injector Control No. 4 circuit in the Injector harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K14) Injector Control No. 4 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 4 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0204-FUEL INJECTOR 4 CIRCUIT - 5.7L

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fueling strategy for the Powertrain Control Module (PCM) requires potentially three fuel pulses per cylinder per cycle. The first pulse is delivered starting at a programmed angle soon after the intake valve closes, for specified time duration. This is for two reasons, one to prevent any fuel from this pulse being delivered in the previous cycle and second to allow fueling to begin as early as possible in the current cycle. The second pulse is delivered for a specified time and is set to end at a programmed angle. The pulse must not extend past the end angle. There can be a separate value for each cylinder under the same operating conditions. This is done for two reasons, one to prevent any fuel from this pulse being delivered during the intake/exhaust valve overlap period, which tends to cause elevated emission levels. Also, allowing fuel to enter each cylinder at a slightly different angle tends to reduce any fuel pressure standing waves in the fuel rail. If the desired total fuel pulse-width increases, a third fuel pulse must be delivered. The third pulse, if necessary, is delivered for a specified time and must end at a programmed angle before the valve closes again. The third pulse in the cycle is controlled by its ending angle. This is also for two reasons, one to prevent any fuel from this pulse being delivered in the next cycle and second to allow fueling to end as late as possible in the current cycle. At high engine speeds, one or more of the pulses may be dropped from the fueling strategy.

With battery voltage greater than 10 Volts. Auto Shutdown Relay energized. Engine speed less than 3000 RPM.

The Powertrain Control Module (PCM) monitors the continuity of the injector circuits as well as the voltage spike created by the collapse of the magnetic field in the injector coil. Any condition that reduces the maximum current flow or the magnitude of the voltage spike can cause this DTC to set.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC Turn the ignition on. With the scan tool, select View DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to reach operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. FUEL INJECTOR 4 CIRCUIT RESISTANCE Turn the ignition off. Disconnect the C2 PCM harness connector. Remove the ASD Relay. NOTE: The resistance of the circuit will vary according to the temperature of the injector coil. Use the table below to determine the resistance range of the injector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the Fuel Injector 4 circuit from the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) and the ASD Relay connector. Fuel Injector Coil Resistance Based on Engine Temperature Temperature Resistance -20° C (-4° F) 10 Ohms (+/-.6 of an Ohm) 20° C (68° F) 12 Ohms (+/-.6 of an Ohm) 60° C (140° F) 14 Ohms (+/-.6 of an Ohm) 100° C (212° F) 16 Ohms (+/-.6 of an Ohm) Is the resistance of the injector within the specified range? Yes Go To 7 . No Go To 3 .
3. FUEL INJECTOR 4 WIRING AND CONNECTOR INSPECTION Turn the ignition off. Verify that the Fuel Injector 4 is properly connected to the injector. Disconnect the Fuel Injector 4 connector and Inspect the terminals for any condition that would result in a poor connection. Using the wiring diagram/schematic as a guide, inspect the Fuel Injector 4 wiring and connector. Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (F342) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE Install the ASD Relay. Turn the ignition on. With the scan tool, actuate the Auto Shutdown (ASD) Relay Control State. Using a 12-volt test light connected to ground, check the (F342) ASD Relay Output circuit in the Fuel Injector 4 harness connector. NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery. Is the test light illuminated and bright? Yes. Go To 5 . No. Repair the excessive resistance or short to ground in the (F342) ASD Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K14) INJECTOR 4 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K14) Injector Control No. 4 circuit from the Fuel Injector harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open in the (K14) Injector Control No. 4 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL INJECTOR 4 Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 4 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the Fuel Injector 4 in accordance with the Service Information. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K14) INJECTOR CONTROL NO. 4 CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C2 PCM harness connector. Measure the resistance between ground and the (K14) Injector Control No. 4 circuit in the Injector harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K14) Injector Control No. 4 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 4 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0205-FUEL INJECTOR 5 CIRCUIT - 3.6L

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fueling strategy for the Powertrain Control Module (PCM) requires potentially three fuel pulses per cylinder per cycle. The first pulse is delivered starting at a programmed angle soon after the intake valve closes, for specified time duration. This is for two reasons, one to prevent any fuel from this pulse being delivered in the previous cycle and second to allow fueling to begin as early as possible in the current cycle. The second pulse is delivered for a specified time and is set to end at a programmed angle. The pulse must not extend past the end angle. There can be a separate value for each cylinder under the same operating conditions. This is done for two reasons, one to prevent any fuel from this pulse being delivered during the intake/exhaust valve overlap period, which tends to cause elevated emission levels. Also, allowing fuel to enter each cylinder at a slightly different angle tends to reduce any fuel pressure standing waves in the fuel rail. If the desired total fuel pulse-width increases, a third fuel pulse must be delivered. The third pulse, if necessary, is delivered for a specified time and must end at a programmed angle before the valve closes again. The third pulse in the cycle is controlled by its ending angle. This is also for two reasons, one to prevent any fuel from this pulse being delivered in the next cycle and second to allow fueling to end as late as possible in the current cycle. At high engine speeds, one or more of the pulses may be dropped from the fueling strategy.

With battery voltage greater than 10 Volts. Auto Shutdown Relay energized. Engine speed less than 3000 RPM.

The Powertrain Control Module (PCM) monitors the continuity of the injector circuits as well as the voltage spike created by the collapse of the magnetic field in the injector coil. Any condition that reduces the maximum current flow or the magnitude of the voltage spike can cause this DTC to set.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 159

Scheme 160

Scheme 161

Scheme 162

1. ACTIVE DTC Turn the ignition on. With the scan tool, select View DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to reach operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. FUEL INJECTOR 5 CIRCUIT RESISTANCE Turn the ignition off. Disconnect the C2 PCM harness connector. Remove the ASD Relay. NOTE: The resistance of the circuit will vary according to the temperature of the injector coil. Use the table below to determine the resistance range of the injector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the Fuel Injector 5 circuit from the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) and the ASD Relay connector. Fuel Injector Coil Resistance Based on Engine Temperature Temperature Resistance -20° C (-4° F) 10 Ohms (+/-.6 of an Ohm) 20° C (68° F) 12 Ohms (+/-.6 of an Ohm) 60° C (140° F) 14 Ohms (+/-.6 of an Ohm) 100° C (212° F) 16 Ohms (+/-.6 of an Ohm) Is the resistance of the injector within the specified range? Yes Go To 7 . No Go To 3 .
3. FUEL INJECTOR 5 WIRING AND CONNECTOR INSPECTION Verify that the Fuel Injector 5 is properly connected to the injector. Disconnect the Fuel Injector 5 connector and Inspect the terminals for any condition that would result in a poor connection. Using the wiring diagram/schematic as a guide, inspect the Fuel Injector 5 wiring and connector. Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (F342) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE Install the ASD Relay. Connect the C2 PCM harness connector. Turn the ignition on. With the scan tool, actuate the Auto Shutdown (ASD) Relay Control State. Using a 12-volt test light connected to ground, check the (F342) ASD Relay Output circuit in the Fuel Injector 5 harness connector. NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery. Is the test light illuminated and bright? Yes. Go To 5 . No. Repair the excessive resistance or short to ground in the (F342) ASD Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K38) INJECTOR 5 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K38) Injector Control No. 5 circuit from the Fuel Injector harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open in the (K38) Injector Control No. 5 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL INJECTOR 5 Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 5 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the Fuel Injector 5 in accordance with the Service Information. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K38) INJECTOR 5 CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C2 PCM harness connector. Measure the resistance between ground and the (K38) Injector Control No. 5 circuit in the Injector harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K38) Injector Control No. 5 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 5 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0205-FUEL INJECTOR 5 CIRCUIT - 5.7L

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fueling strategy for the Powertrain Control Module (PCM) requires potentially three fuel pulses per cylinder per cycle. The first pulse is delivered starting at a programmed angle soon after the intake valve closes, for specified time duration. This is for two reasons, one to prevent any fuel from this pulse being delivered in the previous cycle and second to allow fueling to begin as early as possible in the current cycle. The second pulse is delivered for a specified time and is set to end at a programmed angle. The pulse must not extend past the end angle. There can be a separate value for each cylinder under the same operating conditions. This is done for two reasons, one to prevent any fuel from this pulse being delivered during the intake/exhaust valve overlap period, which tends to cause elevated emission levels. Also, allowing fuel to enter each cylinder at a slightly different angle tends to reduce any fuel pressure standing waves in the fuel rail. If the desired total fuel pulse-width increases, a third fuel pulse must be delivered. The third pulse, if necessary, is delivered for a specified time and must end at a programmed angle before the valve closes again. The third pulse in the cycle is controlled by its ending angle. This is also for two reasons, one to prevent any fuel from this pulse being delivered in the next cycle and second to allow fueling to end as late as possible in the current cycle. At high engine speeds, one or more of the pulses may be dropped from the fueling strategy.

With battery voltage greater than 10 Volts. Auto Shutdown Relay energized. Engine speed less than 3000 RPM.

The Powertrain Control Module (PCM) monitors the continuity of the injector circuits as well as the voltage spike created by the collapse of the magnetic field in the injector coil. Any condition that reduces the maximum current flow or the magnitude of the voltage spike can cause this DTC to set.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC Turn the ignition on. With the scan tool, select View DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to reach operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. FUEL INJECTOR 5 CIRCUIT RESISTANCE Turn the ignition off. Disconnect the C2 PCM harness connector. Remove the ASD Relay. NOTE: The resistance of the circuit will vary according to the temperature of the injector coil. Use the table below to determine the resistance range of the injector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the Fuel Injector 5 circuit from the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) and the ASD Relay connector. Fuel Injector Coil Resistance Based on Engine Temperature Temperature Resistance -20° C (-4° F) 10 Ohms (+/-.6 of an Ohm) 20° C (68° F) 12 Ohms (+/-.6 of an Ohm) 60° C (140° F) 14 Ohms (+/-.6 of an Ohm) 100° C (212° F) 16 Ohms (+/-.6 of an Ohm) Is the resistance of the injector within the specified range? Yes Go To 7 . No Go To 3 .
3. FUEL INJECTOR 5 WIRING AND CONNECTOR INSPECTION Verify that the Fuel Injector 5 is properly connected to the injector. Disconnect the Fuel Injector 5 connector and Inspect the terminals for any condition that would result in a poor connection. Using the wiring diagram/schematic as a guide, inspect the Fuel Injector 5 wiring and connector. Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (F342) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE Install the ASD Relay. Connect the C2 PCM harness connector. Turn the ignition on. With the scan tool, actuate the Auto Shutdown (ASD) Relay Control State. Using a 12-volt test light connected to ground, check the (F342) ASD Relay Output circuit in the Fuel Injector 5 harness connector. NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery. Is the test light illuminated and bright? Yes. Go To 5 . No. Repair the excessive resistance or short to ground in the (F342) ASD Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K38) INJECTOR 5 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K38) Injector Control No. 5 circuit from the Fuel Injector harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open in the (K38) Injector Control No. 5 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL INJECTOR 5 Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 5 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the Fuel Injector 5 in accordance with the Service Information. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K38) INJECTOR 5 CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C2 PCM harness connector. Measure the resistance between ground and the (K38) Injector Control No. 5 circuit in the Injector harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K38) Injector Control No. 5 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 5 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0206-FUEL INJECTOR 6 CIRCUIT - 3.6L

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fueling strategy for the Powertrain Control Module (PCM) requires potentially three fuel pulses per cylinder per cycle. The first pulse is delivered starting at a programmed angle soon after the intake valve closes, for specified time duration. This is for two reasons, one to prevent any fuel from this pulse being delivered in the previous cycle and second to allow fueling to begin as early as possible in the current cycle. The second pulse is delivered for a specified time and is set to end at a programmed angle. The pulse must not extend past the end angle. There can be a separate value for each cylinder under the same operating conditions. This is done for two reasons, one to prevent any fuel from this pulse being delivered during the intake/exhaust valve overlap period, which tends to cause elevated emission levels. Also, allowing fuel to enter each cylinder at a slightly different angle tends to reduce any fuel pressure standing waves in the fuel rail. If the desired total fuel pulse-width increases, a third fuel pulse must be delivered. The third pulse, if necessary, is delivered for a specified time and must end at a programmed angle before the valve closes again. The third pulse in the cycle is controlled by its ending angle. This is also for two reasons, one to prevent any fuel from this pulse being delivered in the next cycle and second to allow fueling to end as late as possible in the current cycle. At high engine speeds, one or more of the pulses may be dropped from the fueling strategy.

With battery voltage greater than 10 Volts. Auto Shutdown Relay energized. Engine speed less than 3000 RPM.

The Powertrain Control Module (PCM) monitors the continuity of the injector circuits as well as the voltage spike created by the collapse of the magnetic field in the injector coil. Any condition that reduces the maximum current flow or the magnitude of the voltage spike can cause this DTC to set.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 163

Scheme 164

Scheme 165

Scheme 166

1. ACTIVE DTC Turn the ignition on. With the scan tool, select View DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to reach operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. FUEL INJECTOR 6 CIRCUIT RESISTANCE Turn the ignition off. Disconnect the C2 PCM harness connector. Remove the ASD Relay. NOTE: The resistance of the circuit will vary according to the temperature of the injector coil. Use the table below to determine the resistance range of the injector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the Fuel Injector 6 circuit from the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) and the ASD Relay connector. Fuel Injector Coil Resistance Based on Engine Temperature Temperature Resistance -20° C (-4° F) 10 Ohms (+/-.6 of an Ohm) 20° C (68° F) 12 Ohms (+/-.6 of an Ohm) 60° C (140° F) 14 Ohms (+/-.6 of an Ohm) 100° C (212° F) 16 Ohms (+/-.6 of an Ohm) Is the resistance of the injector within the specified range? Yes Go To 7 . No Go To 3 .
3. FUEL INJECTOR 6 WIRING AND CONNECTOR INSPECTION Turn the ignition off. Verify that the Fuel Injector 6 is properly connected to the injector. Disconnect the Fuel Injector 6 connector and Inspect the terminals for any condition that would result in a poor connection. Using the wiring diagram/schematic as a guide, inspect the Fuel Injector 6 wiring and connector. Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (F342) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE Install the ASD Relay. Connect the C2 PCM harness connector. Turn the ignition on. With the scan tool, actuate the Auto Shutdown (ASD) Relay Control State. Using a 12-volt test light connected to ground, check the (F342) ASD Relay Output circuit in the Fuel Injector 6 harness connector. NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery. Is the test light illuminated and bright? Yes. Go To 5 . No. Repair the excessive resistance or short to ground in the (F342) ASD Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K58) INJECTOR 6 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K58) Injector Control No. 6 circuit from the Fuel Injector harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 6.0 Ohms? Yes Go To 6 . No Repair the excessive resistance or open in the (K58) Injector Control No. 6 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL INJECTOR 6 Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 6 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the Fuel Injector 6 in accordance with the Service Information. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K58) INJECTOR 6 CONTROL CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C2 PCM harness connector. Measure the resistance between ground and the (K58) Injector Control No. 6 circuit in the Injector harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K58) Injector Control No. 6 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 6 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0206-FUEL INJECTOR 6 CIRCUIT - 5.7L

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fueling strategy for the Powertrain Control Module (PCM) requires potentially three fuel pulses per cylinder per cycle. The first pulse is delivered starting at a programmed angle soon after the intake valve closes, for specified time duration. This is for two reasons, one to prevent any fuel from this pulse being delivered in the previous cycle and second to allow fueling to begin as early as possible in the current cycle. The second pulse is delivered for a specified time and is set to end at a programmed angle. The pulse must not extend past the end angle. There can be a separate value for each cylinder under the same operating conditions. This is done for two reasons, one to prevent any fuel from this pulse being delivered during the intake/exhaust valve overlap period, which tends to cause elevated emission levels. Also, allowing fuel to enter each cylinder at a slightly different angle tends to reduce any fuel pressure standing waves in the fuel rail. If the desired total fuel pulse-width increases, a third fuel pulse must be delivered. The third pulse, if necessary, is delivered for a specified time and must end at a programmed angle before the valve closes again. The third pulse in the cycle is controlled by its ending angle. This is also for two reasons, one to prevent any fuel from this pulse being delivered in the next cycle and second to allow fueling to end as late as possible in the current cycle. At high engine speeds, one or more of the pulses may be dropped from the fueling strategy.

With battery voltage greater than 10 Volts. Auto Shutdown Relay energized. Engine speed less than 3000 RPM.

The Powertrain Control Module (PCM) monitors the continuity of the injector circuits as well as the voltage spike created by the collapse of the magnetic field in the injector coil. Any condition that reduces the maximum current flow or the magnitude of the voltage spike can cause this DTC to set.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC Turn the ignition on. With the scan tool, select View DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to reach operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. FUEL INJECTOR 6 CIRCUIT RESISTANCE Turn the ignition off. Disconnect the C2 PCM harness connector. Remove the ASD Relay. NOTE: The resistance of the circuit will vary according to the temperature of the injector coil. Use the table below to determine the resistance range of the injector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the Fuel Injector 6 circuit from the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) and the ASD Relay connector. Fuel Injector Coil Resistance Based on Engine Temperature Temperature Resistance -20° C (-4° F) 10 Ohms (+/-.6 of an Ohm) 20° C (68° F) 12 Ohms (+/-.6 of an Ohm) 60° C (140° F) 14 Ohms (+/-.6 of an Ohm) 100° C (212° F) 16 Ohms (+/-.6 of an Ohm) Is the resistance of the injector within the specified range? Yes Go To 7 . No Go To 3 .
3. FUEL INJECTOR 6 WIRING AND CONNECTOR INSPECTION Turn the ignition off. Verify that the Fuel Injector 6 is properly connected to the injector. Disconnect the Fuel Injector 6 connector and Inspect the terminals for any condition that would result in a poor connection. Using the wiring diagram/schematic as a guide, inspect the Fuel Injector 6 wiring and connector. Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (F342) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE Install the ASD Relay. Connect the C2 PCM harness connector. Turn the ignition on. With the scan tool, actuate the Auto Shutdown (ASD) Relay Control State. Using a 12-volt test light connected to ground, check the (F342) ASD Relay Output circuit in the Fuel Injector 6 harness connector. NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery. Is the test light illuminated and bright? Yes. Go To 5 . No. Repair the excessive resistance or short to ground in the (F342) ASD Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K58) INJECTOR 6 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K58) Injector Control No. 6 circuit from the Fuel Injector harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 6.0 Ohms? Yes Go To 6 . No Repair the excessive resistance or open in the (K58) Injector Control No. 6 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL INJECTOR 6 Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 6 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the Fuel Injector 6 in accordance with the Service Information. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K58) INJECTOR 6 CONTROL CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C2 PCM harness connector. Measure the resistance between ground and the (K58) Injector Control No. 6 circuit in the Injector harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K58) Injector Control No. 6 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 6 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0207-FUEL INJECTOR 7 CIRCUIT

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fueling strategy for the Powertrain Control Module (PCM) requires potentially three fuel pulses per cylinder per cycle. The first pulse is delivered starting at a programmed angle soon after the intake valve closes, for specified time duration. This is for two reasons, one to prevent any fuel from this pulse being delivered in the previous cycle and second to allow fueling to begin as early as possible in the current cycle. The second pulse is delivered for a specified time and is set to end at a programmed angle. The pulse must not extend past the end angle. There can be a separate value for each cylinder under the same operating conditions. This is done for two reasons, one to prevent any fuel from this pulse being delivered during the intake/exhaust valve overlap period, which tends to cause elevated emission levels. Also, allowing fuel to enter each cylinder at a slightly different angle tends to reduce any fuel pressure standing waves in the fuel rail. If the desired total fuel pulse-width increases, a third fuel pulse must be delivered. The third pulse, if necessary, is delivered for a specified time and must end at a programmed angle before the valve closes again. The third pulse in the cycle is controlled by its ending angle. This is also for two reasons, one to prevent any fuel from this pulse being delivered in the next cycle and second to allow fueling to end as late as possible in the current cycle. At high engine speeds, one or more of the pulses may be dropped from the fueling strategy.

With battery voltage greater than 10 Volts. Auto Shutdown Relay energized. Engine speed less than 3000 RPM.

The Powertrain Control Module (PCM) monitors the continuity of the injector circuits as well as the voltage spike created by the collapse of the magnetic field in the injector coil. Any condition that reduces the maximum current flow or the magnitude of the voltage spike can cause this DTC to set.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 167

Scheme 168

Scheme 169

Scheme 170

1. ACTIVE DTC Turn the ignition on. With the scan tool, select View DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to reach operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. FUEL INJECTOR 7 CIRCUIT RESISTANCE Turn the ignition off. Disconnect the C1 PCM harness connector. Remove the ASD Relay. NOTE: The resistance of the circuit will vary according to the temperature of the injector coil. Use the table below to determine the resistance range of the injector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the Fuel Injector 7 circuit from the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) and the ASD Relay connector. Fuel Injector Coil Resistance Based on Engine Temperature Temperature Resistance -20° C (-4° F) 10 Ohms (+/-.6 of an Ohm) 20° C (68° F) 12 Ohms (+/-.6 of an Ohm) 60° C (140° F) 14 Ohms (+/-.6 of an Ohm) 100° C (212° F) 16 Ohms (+/-.6 of an Ohm) Is the resistance of the injector within the specified range? Yes Go To 7 . No Go To 3 .
3. FUEL INJECTOR 7 WIRING AND CONNECTOR INSPECTION Turn the ignition off. Verify that the Fuel Injector 7 is properly connected to the injector. Disconnect the Fuel Injector 7 connector and Inspect the terminals for any condition that would result in a poor connection. Using the wiring diagram/schematic as a guide, inspect the Fuel Injector 7 wiring and connector. Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (F342) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE Install the ASD Relay. Connect the C2 PCM harness connector. Turn the ignition on. With the scan tool, actuate the Auto Shutdown (ASD) Relay Control State. Using a 12-volt test light connected to ground, check the (F342) ASD Relay Output circuit in the Fuel Injector 7 harness connector. NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery. Is the test light illuminated and bright? Yes. Go To 5 . No. Repair the excessive resistance or short to ground in the (F342) ASD Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K26) INJECTOR 7 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K26) Injector Control No. 7 circuit from the Fuel Injector harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the excessive resistance or open in the (K26) Injector Control No. 7 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL INJECTOR 7 Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 7 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the Fuel Injector 7 in accordance with the Service Information. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K26) INJECTOR 7 CONTROL CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C1 PCM harness connector. Measure the resistance between ground and the (K26) Injector Control No. 7 circuit in the Injector harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K26) Injector Control No. 7 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 7 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0208-FUEL INJECTOR 8 CIRCUIT

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The fueling strategy for the Powertrain Control Module (PCM) requires potentially three fuel pulses per cylinder per cycle. The first pulse is delivered starting at a programmed angle soon after the intake valve closes, for specified time duration. This is for two reasons, one to prevent any fuel from this pulse being delivered in the previous cycle and second to allow fueling to begin as early as possible in the current cycle. The second pulse is delivered for a specified time and is set to end at a programmed angle. The pulse must not extend past the end angle. There can be a separate value for each cylinder under the same operating conditions. This is done for two reasons, one to prevent any fuel from this pulse being delivered during the intake/exhaust valve overlap period, which tends to cause elevated emission levels. Also, allowing fuel to enter each cylinder at a slightly different angle tends to reduce any fuel pressure standing waves in the fuel rail. If the desired total fuel pulse-width increases, a third fuel pulse must be delivered. The third pulse, if necessary, is delivered for a specified time and must end at a programmed angle before the valve closes again. The third pulse in the cycle is controlled by its ending angle. This is also for two reasons, one to prevent any fuel from this pulse being delivered in the next cycle and second to allow fueling to end as late as possible in the current cycle. At high engine speeds, one or more of the pulses may be dropped from the fueling strategy.

With battery voltage greater than 10 Volts. Auto Shutdown Relay energized. Engine speed less than 3000 rpm.

The Powertrain Control Module (PCM) monitors the continuity of the injector circuits as well as the voltage spike created by the collapse of the magnetic field in the injector coil. Any condition that reduces the maximum current flow or the magnitude of the voltage spike can cause this DTC to set.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 171

Scheme 172

Scheme 173

Scheme 174

1. ACTIVE DTC Turn the ignition on. With the scan tool, select View DTCs. Record DTC and Freeze Frame information. Start the engine and allow it to reach operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. FUEL INJECTOR 8 CIRCUIT RESISTANCE Turn the ignition off. Disconnect the C1 PCM harness connector. Remove the ASD Relay. NOTE: The resistance of the circuit will vary according to the temperature of the injector coil. Use the table below to determine the resistance range of the injector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the Fuel Injector 8 circuit from the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) and the ASD Relay connector. Fuel Injector Coil Resistance Based on Engine Temperature Temperature Resistance -20° C (-4° F) 10 Ohms (+/-.6 of an Ohm) 20° C (68° F) 12 Ohms (+/-.6 of an Ohm) 60° C (140° F) 14 Ohms (+/-.6 of an Ohm) 100° C (212° F) 16 Ohms (+/-.6 of an Ohm) Is the resistance of the injector within the specified range? Yes Go To 7 . No Go To 3 .
3. FUEL INJECTOR 8 WIRING AND CONNECTOR INSPECTION Turn the ignition off. Verify that the Fuel Injector 8 is properly connected to the injector. Disconnect the Fuel Injector 8 connector and Inspect the terminals for any condition that would result in a poor connection. Using the wiring diagram/schematic as a guide, inspect the Fuel Injector 8 wiring and connector. Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (F342) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE Install the ASD Relay. Connect the C2 PCM harness connector. Turn the ignition on. With the scan tool, actuate the Auto Shutdown (ASD) Relay Control State. Using a 12-volt test light connected to ground, check the (F342) ASD Relay Output circuit in the Fuel Injector 8 harness connector. NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery. Is the test light illuminated and bright? Yes. Go To 5 . No. Repair the excessive resistance or open in the (F342) ASD Relay Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K28) INJECTOR 8 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K28) Injector Control No. 8 circuit from the Fuel Injector harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open or excessive resistance in the (K28) Injector Control 8 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL INJECTOR 8 Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 8 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the Fuel Injector 8 in accordance with the Service Information. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K28) INJECTOR 8 CONTROL CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C1 PCM harness connector. Measure the resistance between ground and the (K28) Injector Control No. 8 circuit in the Injector harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K28) Injector Control No. 8 circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 8 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Verify that there is good pin to terminal contact in the Injector and Powertrain Control Module connectors. Were there any issues? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

Scheme 175

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The Electronic Throttle Control (ETC) system uses two Throttle Position Sensors (TPS) to monitor the throttle blade position. The TPS sensors 1 and 2 are located within the throttle body assembly. Each sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. Processors are also used to monitor the ETC system data. The processors are located within the Powertrain Control Module (PCM). Each signal circuit provides the processors with a signal voltage proportional to throttle blade movement. The processors share and monitor data to verify that the indicated TPS calculation is correct.

Ignition on and No MAP Sensor DTCs set.

TP Sensor signals do not correlate to the MAP Sensor signal. Two Trip Fault. ETC light will illuminate. P2135 should set with this code also.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 176

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) NOTE: When this DTC is Active the engine speed, torque, and vehicle speed are limited to a Limp in mode. NOTE: Diagnose any other TP Sensor DTCs before continuing. NOTE: The throttle plate and linkage should be free from binding and carbon build up. NOTE: Make sure the throttle plate is at the idle position. NOTE: Inspect the engine for vacuum leaks. Ignition on, engine not running. With a scan tool, read the active DTCs. Is the DTC Active at this time? Yes Go To 2 . No Go To 9 .
2. EXCESSIVE RESISTANCE IN THE (K122) TP SENSOR NO. 2 SIGNAL CIRCUIT Turn the ignition off. Disconnect the C2 PCM harness connector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) along with the Adapter (special tool #8815-1, PCM Pinout Box Adapter) to perform the diagnosis. Using a Voltmeter perform a voltage drop test. Backprobe the (K122) TP Sensor No. 2 Signal circuit at the Throttle Body harness connector and probe the appropriate terminal of the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Make sure the Voltmeter leads are connected so a positive polarity is displayed on the Voltmeter. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Start the engine and allow it to reach normal operating temperature. Monitor the Voltmeter. Is the voltage below 0.5 of a Volt? Yes Go To 3 . No Repair the excessive resistance in the (K122) TP Sensor No. 2 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
3. EXCESSIVE RESISTANCE IN THE (K22) TP SENSOR NO. 1 SIGNAL CIRCUIT Turn the ignition off. Move the Voltmeter leads to backprobe the (K22) TP Sensor No. 1 Signal circuit at the Throttle Body harness connector and to probe the appropriate terminal of the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Make sure the Voltmeter leads are connected so a positive polarity is displayed on the Voltmeter. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Start the engine and allow it to reach normal operating temperature. Monitor the Voltmeter. Is the voltage below 0.5 of a Volt? Yes Go To 4 . No Repair the excessive resistance in the (K22) TP Sensor No. 1 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
4. EXCESSIVE RESISTANCE IN THE (F855) 5-VOLT SUPPLY CIRCUIT Turn the ignition off. Move the Voltmeter leads to backprobe the (F855) 5-Volt Supply circuit at the Throttle Body harness connector and to probe the appropriate terminal of the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Make sure the Voltmeter leads are connected so a positive polarity is displayed on the Voltmeter. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Start the engine and allow it to reach normal operating temperature. Monitor the Voltmeter. Is the voltage below 0.5 of a Volt? Yes Go To 5 . No Repair the excessive resistance in the (F855) 5-Volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. EXCESSIVE RESISTANCE IN THE (K922) TP SENSOR RETURN CIRCUIT Turn the ignition off. Move the Voltmeter leads to backprobe the (K922) TP Sensor Return circuit at the Throttle Body harness connector and to probe the appropriate terminal of the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Make sure the Voltmeter leads are connected so a positive polarity is displayed on the Voltmeter. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Start the engine and allow it to reach normal operating temperature. Monitor the Voltmeter. Is the voltage below 0.5 of a Volt? Yes Go To 6 . No Repair the excessive resistance in the (K922) TP Sensor Return circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. (K22) TP SENSOR NO. 1 SIGNAL CIRCUIT SHORTED TO THE (K122) TP SENSOR NO. 2 SIGNAL CIRCUIT Measure the resistance between the (K22) TP Sensor No. 1 Signal circuit and the (K122) TP Sensor No. 2 Signal circuit at the Throttle Body harness connector. Is the resistance below 5.0 Ohms? Yes Repair the short between the (K122) TP Sensor No. 2 Signal circuit and the (K22) TP Sensor No. 1 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. THROTTLE POSITION SENSOR Turn the ignition off. Connect the C2 PCM harness connector. Ignition on, engine not running. Using the scan tool, monitor the TP Sensor No. 1 and No. 2 voltage. Connect a jumper wire between the (K922) TP Sensor Return circuit and the (K22) TP Sensor No. 1 Signal circuit. NOTE: TP Sensor No. 1 voltage should change from approximately 4.7 Volts to 0.3 of a Volt. For TP Sensor No. 2, connect a jumper wire between (F855) 5-Volt supply circuit and the (K122) TP Sensor No. 2 Signal circuit. NOTE: TP Sensor No. 2 voltage should change from approximately 0 Volts to 5.0 Volts. Is the voltage reading within the listed specification with the jumper wire installed? Yes Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. If OK, disconnect the Battery when replacing the Throttle Body Assembly. Replace the Throttle Body Assembly. After installation is complete, using a scan tool, select the ETC RELEARN function. Refer to «THROTTLE BODY, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 . NOTE: Remove the jumper wire before continuing.
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Throttle Body and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched, or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the service information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
9. THROTTLE FOLLOWER TEST Ignition on, engine not running. Using the scan tool, perform the ETC Throttle Follower Test and monitor the TP Sensor No. 1 or No. 2 voltage. Slowly press the throttle pedal down. The voltage for TP Sensor No. 1 should start at approximately 0.7 of a Volt and increase to approximately 4.3 Volts. The voltage for TP Sensor No. 2 should start at approximately 4.3 Volts and decrease to approximately 0.7 of a Volt. Is the voltage within the range of the listed specification for the appropriate Sensor? Yes Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. If OK, disconnect the Battery when replacing the Throttle Body Assembly. Replace the Throttle Body Assembly. After installation is complete, using a scan tool select the ETC RELEARN function. Refer to «THROTTLE BODY, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0222-THROTTLE POSITION SENSOR 2 CIRCUIT LOW

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The Electronic Throttle Control (ETC) system uses two Throttle Position Sensors (TPS) to monitor the throttle blade position. The TPS sensors 1 and 2 are located within the throttle body assembly. Each sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. Processors are also used to monitor the ETC system data. The processors are located within the Powertrain Control Module (PCM). Each signal circuit provides the processors with a signal voltage proportional to throttle blade movement. The processors share and monitor data to verify that the indicated TPS calculation is correct.

With the ignition on. Battery voltage greater than 10 Volts.

Throttle Position Sensor voltage at the Powertrain Control Module (PCM) is less than 0.16 of a Volt for 0.7 of a second. One Trip Fault. Three good trips to turn off the MIL. ETC light will illuminate.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 177

Scheme 178

Scheme 179

Scheme 180

Scheme 181

Scheme 182

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) NOTE: When this DTC is Active the engine speed, torque and vehicle speed are limited to a Limp in mode. NOTE: If a 5 Volt supply DTC has also set, diagnose the 5 Volt DTC before continuing. NOTE: Make sure the throttle moves freely and does not hang up at Wide Open Throttle, by performing the Throttle Follower Test NOTE: If P2101 is also set, then make sure that the blade moves freely and does not hang up near Wide Open Throttle before trying to repair P0222. Ignition on, engine not running. Using the scan tool, read the active DTCs. Is the DTC Active at this time? Yes Go To 2 . No Go To 11 .
2. P0122 ALSO SET Was the P0122-TP SENSOR NO. 1 VOLTAGE LOW DTC set along with the P0222? Yes Go To 3 . No Go To 4 .
3. (K855) 5 VOLT SUPPLY CIRCUIT Turn the ignition off. Disconnect the Throttle Body harness connector. Ignition on, engine not running. Measure the voltage on the (K855) 5 Volt Supply circuit in the Throttle Body harness connector. Is the voltage between 4.5 to 5.2 Volts? Yes Go To 4 . No Go To 8 .
4. THROTTLE POSITION SENSOR Connect a jumper wire between the (K855) 5 Volt Supply circuit and the (K122) TP Sensor No. 2 Signal circuit in the Throttle Body harness connector. Using the scan tool, monitor the TP Sensor No. 2 voltage. Is the voltage between 4.8 and 5.2 Volts with the jumper wire installed? Yes Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. If OK, disconnect the Battery when replacing the Throttle Body Assembly. Replace the Throttle Body Assembly. After installation is complete, with a scan tool select the ETC RELEARN function. Refer to «THROTTLE BODY, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 . NOTE: Remove the jumper wire before continuing.
5. (K122) TP SENSOR NO. 2 SIGNAL CIRCUIT OPEN Turn the ignition off. Disconnect the C2 PCM harness connector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K122) TP Sensor No. 2 Signal circuit from the Throttle Body harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open in the (K122) TP Sensor No. 2 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. (K122) TP SENSOR NO. 2 SIGNAL CIRCUIT SHORTED TO GROUND Measure the resistance between ground and the (K122) TP Sensor No. 2 Signal circuit at the Throttle Body harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K122) TP Sensor No. 2 Signal. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. (K122) TP SENSOR NO. 2 SIGNAL CIRCUIT SHORTED TO THE (K922) TP SENSOR RETURN CIRCUIT Measure the resistance between the (K122) TP Sensor No. 2 Signal circuit and the (K922) TP Sensor Return circuit at the Throttle Body harness connector. Is the resistance below 100 Ohms? Yes Repair the short between the (K922) TP Sensor Return circuit and the (K122) TP Sensor No. 2 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 10 .
8. (K855) 5 VOLT SUPPLY CIRCUIT OPEN Turn the ignition off. Disconnect the C2 PCM harness connector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K855) 5 Volt Supply circuit from the Throttle Body harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 9 . No Repair the open in the (K855) 5 Volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
9. (K855) 5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND Measure the resistance between ground and the (K855) 5 Volt Supply circuit at the Throttle Body harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K855) 5 Volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 10 .
10. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Throttle Body and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
11. THROTTLE FOLLOWER TEST Ignition on, engine not running. Using the scan tool, perform the ETC Throttle Follower Test. Monitor the TP Sensor No. 2 voltage while slowly pressing the Throttle pedal down. Is there a smooth voltage change from approximately 4.3 Volts and decrease to approximately 0.7 of a Volt? Yes Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. If OK, disconnect the Battery when replacing the Throttle Body Assembly. Replace the Throttle Body Assembly. After installation is complete, with a scan tool select the ETC RELEARN function. Refer to «THROTTLE BODY, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0223-THROTTLE POSITION SENSOR 2 CIRCUIT HIGH

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The Electronic Throttle Control (ETC) system uses two Throttle Position Sensors (TPS) to monitor the throttle blade position. The TPS sensors 1 and 2 are located within the throttle body assembly. Each sensor has a 5 Volt reference circuit, a low reference circuit and a signal circuit. Processors are also used to monitor the ETC system data. The processors are located within the Powertrain Control Module (PCM). Each signal circuit provides the processors with a signal voltage proportional to throttle blade movement. The processors share and monitor data to verify that the indicated TPS calculation is correct.

With the ignition on.

Throttle Position Sensor No. 2 Signal circuit voltage is greater than 4.9 Volts for 25 ms. One Trip Fault. ETC light will illuminate.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 183

Scheme 184

Scheme 185

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) NOTE: When this DTC is Active the engine speed, torque and vehicle speed are limited to a Limp in mode. NOTE: If a 5 Volt supply DTC has also set, diagnose the 5 Volt DTC before continuing. Ignition on, engine not running. With the scan tool, read the active DTCs. Is the DTC Active at this time? Yes Go To 2 . No Go To 7 .
2. THROTTLE POSITION SENSOR Turn the ignition off. Disconnect the Throttle Body Assembly harness connector. Ignition on, engine not running. With the scan tool monitor the TP Sensor No. 2 voltage. Is the voltage below 0.5 of a Volt? Yes Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. If OK, disconnect the Battery when replacing the Throttle Body Assembly. Replace the Throttle Body Assembly. After installation is complete, using a scan tool select the ETC RELEARN function. Refer to «THROTTLE BODY, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. (K122) TP SENSOR NO. 2 SIGNAL CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Disconnect the C2 PCM harness connector. Ignition on, engine not running. Measure the voltage on the (K122) TP Sensor No. 2 Signal circuit at the Throttle Body harness connector. Is there any voltage present? Yes Repair the short to voltage in the (K122) TP Sensor No. 2 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (K122) TP SENSOR NO. 2 SIGNAL CIRCUIT SHORTED TO THE (F855) 5 VOLT SUPPLY CIRCUIT Measure the resistance between the (K122) TP Sensor No. 2 Signal circuit and the (F855) 5 Volt Supply circuit at the Throttle Body harness connector. Is the resistance below 100 Ohms? Yes Repair the short between the (K122) TP Sensor No. 2 Signal circuit and the (F855) 5 Volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 .
5. (K922) TP SENSOR RETURN CIRCUIT OPEN CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K922) TP Sensor Return circuit from the Throttle Body harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open in the (K922) TP Sensor Return circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Throttle Body and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. THROTTLE FOLLOWER TEST Using the scan tool, perform the ETC Throttle Follower Test. Monitor the TP Sensor No. 2 voltage while slowly pressing the Throttle pedal down. Is there a smooth voltage change from approximately 4.3 Volts and decrease to approximately 0.7 of a Volt? Yes Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. If OK, disconnect the Battery when replacing the Throttle Body Assembly. Replace the Throttle Body Assembly. After installation is complete, using a scan tool select the ETC RELEARN function. Refer to «THROTTLE BODY, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0298-ENGINE OIL TEMPERATURE TOO HIGH

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The Engine Oil Temperature (EOT) sensor is a variable resistor that measures the temperature of the engine oil. The Powertrain Control Module (PCM) supplies a 5 Volt reference and a ground to the sensors low reference signal circuit. When the oil temperature is low, the sensor resistance is high. When the oil temperature is high, the sensor resistance is low.

The engine oil temperature has dropped below a calibrated value. Engine start up.

The Engine Oil temperature rises faster than a calibrated modeled temperature. When the actual oil temperature exceeds the high boundary of the calibrated modeled temperature for three minutes the fault is set. Two trip fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. DTC IS ACTIVE NOTE: Diagnose any other Oil Temperature sensor or system voltage DTCs before continuing. Turn the ignition off. If possible, allow the vehicle to sit with the ignition off for more than 60 minutes in an environment where the temperature will allow the oil temperature to cool down. Start the engine and allow it to reach normal operating conditions. With the scan tool, select View DTCs. Is the status Active or Pending for this DTC? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. ENGINE OIL/ENGINE MECHANICAL NOTE: The following items should be considered before determining the cause of this DTC. Failure to do so may lead to misdiagnosis. ENGINE MECHANICAL TOLERANCES OUT OF SPECIFICATION ENGINE OIL PRESSURE OUT OF SPECIFICATION LOW ENGINE OIL DETERIORATED OR DIRTY OIL ENGINE OIL CONTAMINATED (i.e., coolant and/or fuel) If any of the above conditions are found, repair as necessary. Were any of the above conditions present? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. ENGINE OIL TEMPERATURE SENSOR VOLTAGE Turn the ignition off. Disconnect the Engine Oil Temperature Sensor harness connector. Turn the ignition on. With the scan tool, read the Engine Oil Temperature Sensor voltage. NOTE: The sensor voltage should be approximately 5.0 Volts (plus or minus.1 of a Volt) with the connector disconnected. Does the scan tool display the voltage as described above? Yes Go To 4 . No Go To 5 .
4. ENGINE OIL TEMPERATURE SENSOR Turn the ignition off. Connect a jumper wire between the (G24) EOT Signal circuit and the (K900) Sensor Ground circuit in the Engine Oil Temperature Sensor harness connector. Turn the ignition on. With the scan tool, read the Engine Oil Temperature Sensor voltage. NOTE: The sensor voltage should be approximately 0.0 Volts (plus or minus.1 of a Volt) with the jumper wire in place. Does the scan tool display the voltage as described above? Yes Verify that there is good pin to terminal contact in the EOT Sensor and Control Module connectors. Replace the Engine Oil Temperature Sensor if no problems were found with the connectors. Refer to «SENSOR, OIL TEMPERATURE, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/mechanical/#36l-engine-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 .
5. (G24) EOT SIGNAL CIRCUIT HIGH RESISTANCE Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (G24) Engine Oil Temp Signal circuit from the Engine Oil Temp Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Start the engine. Is the resistance below 5.0 Ohms? Yes Go To 6 . No Repair the open or excessive resistance in the (G24) Engine Oil Temp Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. (K900) SENSOR GROUND CIRCUIT HIGH RESISTANCE CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K900) Sensor ground circuit from the Engine Oil Temp Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 7 . No Repair the (K900) Sensor Ground circuit for high resistance. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Engine Oil Temperature Sensor and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors. Look for the data to change or for the DTC to reset during the wiggle test. Perform any Technical Service Bulletins that may apply. Were any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0300-MULTIPLE CYLINDER MISFIRE

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The misfire detection monitor, software strategy in the Powertrain Control Module (PCM), is designed to detect an engine misfire. The PCM uses the Crankshaft (CKP) and Camshaft (CMP) sensors to determine when an engine misfire event is occurring and determine individual misfire events by monitoring the crankshaft rotational speed. A misfire is nothing more than a lack of combustion, which can be caused by poor fuel quality or metering, low compression, lack of spark or unmetered air entering the engine. Other possible causes such as uncommanded Exhaust Gas Recirculating (EGR) flow can also cause a misfire. In the case of multiple cylinders misfiring or the PCM not determining the specific cylinder misfiring, P0300 Multiple Cylinder Misfire will set.

Any time the engine is running and the adaptive numerator has been successfully updated.

The threshold to set the fault is application specific; it is tied to the level of misfire that will cause emissions to increase to 1.5 times the standard or in some cases 1%. It is always a two trip fault above the calibrated RPM. It takes one fail to set a Pending Fault and two trips to set the MIL. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC Diagnose and repair any other active component or circuit DTCs before continuing with this procedure. Turn the ignition on. With the scan tool, select View DTCs. Copy DTC and Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, view the Misfire Monitor to see which cylinders are effected. NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to set or to show misfires on a particular cylinder. Are there excessive misfires shown or is the DTC pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. VISUAL INSPECTION NOTE: Anything that affects the speed of the crankshaft can cause a misfire DTC. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. NOTE: Misfires detected during a deceleration are indicators of mechanical concerns Visually inspect the engine for any of the following conditions: Worn serpentine belt. Refer to «BELT, SERPENTINE, DIAGNOSIS AND TESTING»(/jeep/grand-cherokee/wk2-2010-2013/remont/accessory-drive-belts/#engine-cooling-system) . Binding Engine-Driven accessories: A/C Compressor, P/S Pump, Water pump. Misalignment of the Water pump, P/S Pump and A/C Compressor pulleys. Corroded PCM power and ground circuits. Improper CKP, CMP, MAP and TP sensor mounting. Poor connector/terminal to component connection for CKP sensor, CMP sensor, MAP sensor, TP sensor, fuel injector, ignition coil, etc. Vacuum leaks. Restricted Exhaust system. Perform the CHECKING EXHAUST RESTRICTION diagnostic procedure. Refer to «CHECKING EXHAUST RESTRICTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__checking-exhaust-restriction) . Restricted Air Induction system. Internal engine component failures. Overfilled engine oil or transmission. Extremely out of balance tires or warped brake rotors. Were any of the above conditions present? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. IGNITION SYSTEM OPERATION WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Turn the ignition off. Remove the Ignition Coils. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Connect the Ignition Coil harness connectors. Disconnect the Fuel Injector harness connector of the cylinder being tested. Install a spark tester on the Ignition Coil. While cranking the engine observe the spark coming from the spark tester. NOTE: A crisp blue spark that is able to jump the gap of the spark tester should be generated at the coil on plug and at the end of the ignition wire. Is good spark present? Yes Go To 4 . No Go To 13 . NOTE: Connect the Fuel Injector harness connector before continuing.
4. SPARK PLUG Turn the ignition off. Remove the Spark Plug(s) in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Inspect the Spark Plug(s) for the following conditions: Cracks Carbon Tracking Foreign Material Gap size out of specifications Loose or broken electrode NOTE: Lightly tap the bottom of the spark plug on a solid surface. The electrode in the spark plug should not move. Were any of the above conditions present? Yes Replace the Spark Plug in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 .
5. FUEL PRESSURE CHECK WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Before continuing, visually and physically inspect the fuel delivery system for external leaks or damage. Repair/replace as necessary. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) to the fuel rail. Start the engine and observe the fuel pressure reading. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Choose a conclusion that best matches your fuel pressure reading. Within Specification Go To 6 . Below Specification Go To 11 . Above Specification Replace the fuel pressure regulator. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL PRESSURE LEAK DOWN Perform the Fuel Pressure Leak Down Test. Refer to «FUEL PRESSURE LEAK DOWN»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__fuel-pressure-leak-down) . Were any repairs made after performing the leak down test? Yes Testing complete. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. FUEL INJECTOR OPERATION WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. CAUTION: After each Fuel Injector actuation, start the engine to clean the cylinder of fuel. Failure to do so could cause engine damage. Open the Fuel System Isolation Valve. Start the engine and allow the fuel pressure to reach maximum pressure. Turn the ignition off. Ignition on, engine not running. Using the scan tool, actuate the Fuel Injector for the cylinder that indicated the misfire. Monitor the fuel pressure gauge. Does the fuel pressure gauge indicate a drop in fuel pressure? Yes Go To 8 . No Go To 9 . NOTE: Turn the ignition off, remove the Fuel Pressure Decay Tester and connect the fuel lines before continuing.
8. ENGINE MECHANICAL Check for any of the following conditions/mechanical problems: ENGINE VACUUM - must be at least 13 inches in neutral ENGINE VALVE TIMING - must be within specifications ENGINE COMPRESSION - must be within specifications CYLINDER LEAKAGE TEST - must be within specifications ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks. ENGINE PCV SYSTEM - must flow freely TORQUE CONVERTER STALL SPEED - must be within specifications POWER BRAKE BOOSTER - no internal vacuum leaks FUEL - must be free of contamination VALVE SPRINGS - cannot be weak or broken CAM LOBES - must not be worn excessively CAM SHAFTS - must not be worn or have excessive endplay Are there any engine mechanical problems? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
9. FUEL INJECTOR CONTROL Turn the ignition off. Disconnect the Fuel Injector harness connector of the misfiring cylinder. Ignition on, engine not running. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. Install an Injector Noid light. With the scan tool, actuate the Fuel Injector. Does the Noid light blink/flicker during the actuation? Yes Verify that there is good pin to terminal contact in the related Injector and the Powertrain Control Module connectors. Replace the Fuel Injector. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 10 .
10. INJECTOR CONTROL CIRCUIT Turn the ignition off. Disconnect the Fuel Injector harness connector. Disconnect the PCM harness connectors. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Injector Control circuit for an open, short to ground and short to voltage. Was a problem found with the Injector Control circuit? Yes Repair the excessive resistance or short in the Injector Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
11. FUEL SUPPLY LINE RESTRICTED WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Raise the vehicle on a hoist and disconnect the fuel pressure line at the fuel pump module. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) between the fuel supply line and the fuel pump module. Ignition on, engine not running. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Is the fuel pressure within specification? Yes Repair or replace fuel supply line as necessary. Refer to «TUBE(S), FUEL, DESCRIPTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 12 .
12. FUEL PUMP INLET STRAINER WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Is the Fuel Inlet Strainer plugged? Yes Replace the Fuel Pump Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Before continuing, check the Fuel Pump Module harness connector terminals for corrosion, damage or terminal push out. Make sure the ground circuit is functional. Repair as necessary. Replace the Fuel Pump Module. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
13. IGNITION COIL WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Disconnect the Ignition Coil harness connector. Using a 12-volt test light connected to 12-volts, probe the Ignition Coil Control circuit. Crank the engine for five seconds while observing the test light. NOTE: The primary resistance of the Ignition coil is 0.558 to 0.682 of an Ohm at 25° C (77° F). Does the test light brightly blink/flicker? Yes Verify that there is good pin to terminal contact in the related Coil and the Powertrain Control Module connectors. If OK, replace the Ignition Coil in accordance with the Service Information. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 14 .
14. COIL CONTROL CIRCUIT Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Coil Control circuit for an open, short to ground and short to voltage. Was a problem found with the Coil Control circuit? Yes Repair the Coil Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
15. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the related Sensor, Coil, Injector and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related Sensors, Coils, Injectors and the Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0301-CYLINDER 1 MISFIRE

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

Thoery of operation

The misfire detection monitor, software strategy in the Powertrain Control Module (PCM), is designed to detect an engine misfire. The PCM uses the Crankshaft (CKP) and Camshaft (CMP) sensors to determine when an engine misfire event is occurring and determine individual misfire events by monitoring the crankshaft rotational speed. A misfire is nothing more than a lack of combustion, which can be caused by poor fuel quality or metering, low compression, lack of spark or unmetered air entering the engine. Other possible causes such as uncommanded Exhaust Gas Recirculatin (EGR) flow can also cause a misfire. In the case of multiple cylinders misfiring, or the PCM not determining the specific cylinder misfiring, P0300 Multiple Cylinder Misfire will set.

Any time the engine is running, and the adaptive numerator has been successfully updated.

The threshold to set the fault is application specific; it is tied to the level of misfire that will cause emissions to increase to 1.5 times the standard or in some cases 1%. It is always a two trip fault above the calibrated RPM. It takes one fail to set a Pending Fault and two trips to set the MIL. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC Diagnose and repair any other active component or circuit DTCs before continuing with this procedure. Turn the ignition on. With the scan tool, select View DTCs. Copy DTC and Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, view the Misfire Monitor to see which cylinders are effected. NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to set or to show misfires on a particular cylinder. Are there excessive misfires shown or is the DTC pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. VISUAL INSPECTION NOTE: Anything that affects the speed of the crankshaft can cause a misfire DTC. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. NOTE: Misfires detected during a deceleration are indicators of mechanical concerns Visually inspect the engine for any of the following conditions: Worn serpentine belt. Refer to «BELT, SERPENTINE, DIAGNOSIS AND TESTING»(/jeep/grand-cherokee/wk2-2010-2013/remont/accessory-drive-belts/#engine-cooling-system) . Binding Engine-Driven accessories: A/C Compressor, P/S Pump, Water pump. Misalignment of the Water pump, P/S Pump and A/C Compressor pulleys. Corroded PCM power and ground circuits. Improper CKP, CMP, MAP and TP sensor mounting. Poor connector/terminal to component connection for CKP sensor, CMP sensor, MAP sensor, TP sensor, fuel injector, ignition coil, etc. Vacuum leaks. Restricted Exhaust system. Perform the CHECKING EXHAUST RESTRICTION diagnostic procedure. Refer to «CHECKING EXHAUST RESTRICTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__checking-exhaust-restriction) . Restricted Air Induction system. Internal engine component failures. Overfilled engine oil or transmission. Extremely out of balance tires or warped brake rotors. Were any of the above conditions present? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. IGNITION SYSTEM OPERATION WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Turn the ignition off. Remove the Ignition Coils. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Connect the Ignition Coil harness connectors. Disconnect the Fuel Injector harness connector of the cylinder being tested. Install a spark tester on the Ignition Coil. While cranking the engine observe the spark coming from the spark tester. NOTE: A crisp blue spark that is able to jump the gap of the spark tester should be generated at the coil on plug and at the end of the ignition wire. Is good spark present? Yes Go To 4 . No Go To 13 . NOTE: Connect the Fuel Injector harness connector before continuing.
4. SPARK PLUG Turn the ignition off. Remove the Spark Plug(s) in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Inspect the Spark Plug(s) for the following conditions: Cracks Carbon Tracking Foreign Material Gap size out of specifications Loose or broken electrode NOTE: Lightly tap the bottom of the spark plug on a solid surface. The electrode in the spark plug should not move. Were any of the above conditions present? Yes Replace the Spark Plug in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 .
5. FUEL PRESSURE CHECK WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Before continuing, visually and physically inspect the fuel delivery system for external leaks or damage. Repair/replace as necessary. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) to the fuel rail. Start the engine and observe the fuel pressure reading. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Choose a conclusion that best matches your fuel pressure reading. Within Specification Go To 6 . Below Specification Go To 11 . Above Specification Replace the fuel pressure regulator. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL PRESSURE LEAK DOWN Perform the Fuel Pressure Leak Down Test. Refer to «FUEL PRESSURE LEAK DOWN»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__fuel-pressure-leak-down) . Were any repairs made after performing the leak down test? Yes Testing complete. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. FUEL INJECTOR OPERATION WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. CAUTION: After each Fuel Injector actuation, start the engine to clean the cylinder of fuel. Failure to do so could cause engine damage. Open the Fuel System Isolation Valve. Start the engine and allow the fuel pressure to reach maximum pressure. Turn the ignition off. Ignition on, engine not running. Using the scan tool, actuate the Fuel Injector for the cylinder that indicated the misfire. Monitor the fuel pressure gauge. Does the fuel pressure gauge indicate a drop in fuel pressure? Yes Go To 8 . No Go To 9 . NOTE: Turn the ignition off, remove the Fuel Pressure Decay Tester and connect the fuel lines before continuing.
8. ENGINE MECHANICAL Check for any of the following conditions/mechanical problems: ENGINE VACUUM - must be at least 13 inches in neutral ENGINE VALVE TIMING - must be within specifications ENGINE COMPRESSION - must be within specifications CYLINDER LEAKAGE TEST - must be within specifications ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks. ENGINE PCV SYSTEM - must flow freely TORQUE CONVERTER STALL SPEED - must be within specifications POWER BRAKE BOOSTER - no internal vacuum leaks FUEL - must be free of contamination VALVE SPRINGS - cannot be weak or broken CAM LOBES - must not be worn excessively CAM SHAFTS - must not be worn or have excessive endplay Are there any engine mechanical problems? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
9. FUEL INJECTOR CONTROL Turn the ignition off. Disconnect the Fuel Injector harness connector of the misfiring cylinder. Ignition on, engine not running. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. Install an Injector Noid light. With the scan tool, actuate the Fuel Injector. Does the Noid light blink/flicker during the actuation? Yes Verify that there is good pin to terminal contact in the related Injector and the Powertrain Control Module connectors. Replace the Fuel Injector. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 10 .
10. INJECTOR CONTROL CIRCUIT Turn the ignition off. Disconnect the Fuel Injector harness connector. Disconnect the PCM harness connectors. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Injector Control circuit for an open, short to ground and short to voltage. Was a problem found with the Injector Control circuit? Yes Repair the excessive resistance or short in the Injector Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
11. FUEL SUPPLY LINE RESTRICTED WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Raise the vehicle on a hoist and disconnect the fuel pressure line at the fuel pump module. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) between the fuel supply line and the fuel pump module. Ignition on, engine not running. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Is the fuel pressure within specification? Yes Repair or replace fuel supply line as necessary. Refer to «TUBE(S), FUEL, DESCRIPTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 12 .
12. FUEL PUMP INLET STRAINER WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Is the Fuel Inlet Strainer plugged? Yes Replace the Fuel Pump Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Before continuing, check the Fuel Pump Module harness connector terminals for corrosion, damage or terminal push out. Make sure the ground circuit is functional. Repair as necessary. Replace the Fuel Pump Module. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
13. IGNITION COIL WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Disconnect the Ignition Coil harness connector. Using a 12-volt test light connected to 12-volts, probe the Ignition Coil Control circuit. Crank the engine for five seconds while observing the test light. NOTE: The primary resistance of the Ignition coil is 0.558 to 0.682 of an Ohm at 25° C (77° F). Does the test light brightly blink/flicker? Yes Verify that there is good pin to terminal contact in the related Coil and the Powertrain Control Module connectors. If OK, replace the Ignition Coil in accordance with the Service Information. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 14 .
14. COIL CONTROL CIRCUIT Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Coil Control circuit for an open, short to ground and short to voltage. Was a problem found with the Coil Control circuit? Yes Repair the Coil Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
15. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the related Sensor, Coil, Injector and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related Sensors, Coils, Injectors and the Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0302-CYLINDER 2 MISFIRE

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

Thoery of operation

The misfire detection monitor, software strategy in the Powertrain Control Module (PCM), is designed to detect an engine misfire. The PCM uses the Crankshaft (CKP) and Camshaft (CMP) sensors to determine when an engine misfire event is occurring and determine individual misfire events by monitoring the crankshaft rotational speed. A misfire is nothing more than a lack of combustion, which can be caused by poor fuel quality or metering, low compression, lack of spark or unmetered air entering the engine. Other possible causes such as uncommanded Exhaust Gas Recirculatin (EGR) flow can also cause a misfire. In the case of multiple cylinders misfiring, or the PCM not determining the specific cylinder misfiring, P0300 Multiple Cylinder Misfire will set.

Any time the engine is running, and the adaptive numerator has been successfully updated.

The threshold to set the fault is application specific; it is tied to the level of misfire that will cause emissions to increase to 1.5 times the standard or in some cases 1%. It is always a two trip fault above the calibrated RPM. It takes one fail to set a Pending Fault and two trips to set the MIL. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC Diagnose and repair any other active component or circuit DTCs before continuing with this procedure. Turn the ignition on. With the scan tool, select View DTCs. Copy DTC and Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, view the Misfire Monitor to see which cylinders are effected. NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to set or to show misfires on a particular cylinder. Are there excessive misfires shown or is the DTC pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. VISUAL INSPECTION NOTE: Anything that affects the speed of the crankshaft can cause a misfire DTC. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. NOTE: Misfires detected during a deceleration are indicators of mechanical concerns Visually inspect the engine for any of the following conditions: Worn serpentine belt. Refer to «BELT, SERPENTINE, DIAGNOSIS AND TESTING»(/jeep/grand-cherokee/wk2-2010-2013/remont/accessory-drive-belts/#engine-cooling-system) . Binding Engine-Driven accessories: A/C Compressor, P/S Pump, Water pump. Misalignment of the Water pump, P/S Pump and A/C Compressor pulleys. Corroded PCM power and ground circuits. Improper CKP, CMP, MAP and TP sensor mounting. Poor connector/terminal to component connection for CKP sensor, CMP sensor, MAP sensor, TP sensor, fuel injector, ignition coil, etc. Vacuum leaks. Restricted Exhaust system. Perform the CHECKING EXHAUST RESTRICTION diagnostic procedure. Refer to «CHECKING EXHAUST RESTRICTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__checking-exhaust-restriction) . Restricted Air Induction system. Internal engine component failures. Overfilled engine oil or transmission. Extremely out of balance tires or warped brake rotors. Were any of the above conditions present? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. IGNITION SYSTEM OPERATION WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Turn the ignition off. Remove the Ignition Coils. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Connect the Ignition Coil harness connectors. Disconnect the Fuel Injector harness connector of the cylinder being tested. Install a spark tester on the Ignition Coil. While cranking the engine observe the spark coming from the spark tester. NOTE: A crisp blue spark that is able to jump the gap of the spark tester should be generated at the coil on plug and at the end of the ignition wire. Is good spark present? Yes Go To 4 . No Go To 13 . NOTE: Connect the Fuel Injector harness connector before continuing.
4. SPARK PLUG Turn the ignition off. Remove the Spark Plug(s) in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Inspect the Spark Plug(s) for the following conditions: Cracks Carbon Tracking Foreign Material Gap size out of specifications Loose or broken electrode NOTE: Lightly tap the bottom of the spark plug on a solid surface. The electrode in the spark plug should not move. Were any of the above conditions present? Yes Replace the Spark Plug in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 .
5. FUEL PRESSURE CHECK WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Before continuing, visually and physically inspect the fuel delivery system for external leaks or damage. Repair/replace as necessary. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) to the fuel rail. Start the engine and observe the fuel pressure reading. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Choose a conclusion that best matches your fuel pressure reading. Within Specification Go To 6 . Below Specification Go To 11 . Above Specification Replace the fuel pressure regulator. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL PRESSURE LEAK DOWN Perform the Fuel Pressure Leak Down Test. Refer to «FUEL PRESSURE LEAK DOWN»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__fuel-pressure-leak-down) . Were any repairs made after performing the leak down test? Yes Testing complete. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. FUEL INJECTOR OPERATION WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. CAUTION: After each Fuel Injector actuation, start the engine to clean the cylinder of fuel. Failure to do so could cause engine damage. Open the Fuel System Isolation Valve. Start the engine and allow the fuel pressure to reach maximum pressure. Turn the ignition off. Ignition on, engine not running. Using the scan tool, actuate the Fuel Injector for the cylinder that indicated the misfire. Monitor the fuel pressure gauge. Does the fuel pressure gauge indicate a drop in fuel pressure? Yes Go To 8 . No Go To 9 . NOTE: Turn the ignition off, remove the Fuel Pressure Decay Tester and connect the fuel lines before continuing.
8. ENGINE MECHANICAL Check for any of the following conditions/mechanical problems: ENGINE VACUUM - must be at least 13 inches in neutral ENGINE VALVE TIMING - must be within specifications ENGINE COMPRESSION - must be within specifications CYLINDER LEAKAGE TEST - must be within specifications ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks. ENGINE PCV SYSTEM - must flow freely TORQUE CONVERTER STALL SPEED - must be within specifications POWER BRAKE BOOSTER - no internal vacuum leaks FUEL - must be free of contamination VALVE SPRINGS - cannot be weak or broken CAM LOBES - must not be worn excessively CAM SHAFTS - must not be worn or have excessive endplay Are there any engine mechanical problems? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
9. FUEL INJECTOR CONTROL Turn the ignition off. Disconnect the Fuel Injector harness connector of the misfiring cylinder. Ignition on, engine not running. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. Install an Injector Noid light. With the scan tool, actuate the Fuel Injector. Does the Noid light blink/flicker during the actuation? Yes Verify that there is good pin to terminal contact in the related Injector and the Powertrain Control Module connectors. Replace the Fuel Injector. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 10 .
10. INJECTOR CONTROL CIRCUIT Turn the ignition off. Disconnect the Fuel Injector harness connector. Disconnect the PCM harness connectors. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Injector Control circuit for an open, short to ground and short to voltage. Was a problem found with the Injector Control circuit? Yes Repair the excessive resistance or short in the Injector Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
11. FUEL SUPPLY LINE RESTRICTED WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Raise the vehicle on a hoist and disconnect the fuel pressure line at the fuel pump module. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) between the fuel supply line and the fuel pump module. Ignition on, engine not running. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Is the fuel pressure within specification? Yes Repair or replace fuel supply line as necessary. Refer to «TUBE(S), FUEL, DESCRIPTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 12 .
12. FUEL PUMP INLET STRAINER WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Is the Fuel Inlet Strainer plugged? Yes Replace the Fuel Pump Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Before continuing, check the Fuel Pump Module harness connector terminals for corrosion, damage or terminal push out. Make sure the ground circuit is functional. Repair as necessary. Replace the Fuel Pump Module. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
13. IGNITION COIL WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Disconnect the Ignition Coil harness connector. Using a 12-volt test light connected to 12-volts, probe the Ignition Coil Control circuit. Crank the engine for five seconds while observing the test light. NOTE: The primary resistance of the Ignition coil is 0.558 to 0.682 of an Ohm at 25° C (77° F). Does the test light brightly blink/flicker? Yes Verify that there is good pin to terminal contact in the related Coil and the Powertrain Control Module connectors. If OK, replace the Ignition Coil in accordance with the Service Information. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 14 .
14. COIL CONTROL CIRCUIT Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Coil Control circuit for an open, short to ground and short to voltage. Was a problem found with the Coil Control circuit? Yes Repair the Coil Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
15. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the related Sensor, Coil, Injector and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related Sensors, Coils, Injectors and the Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0303-CYLINDER 3 MISFIRE

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

Thoery of operation

The misfire detection monitor, software strategy in the Powertrain Control Module (PCM), is designed to detect an engine misfire. The PCM uses the Crankshaft (CKP) and Camshaft (CMP) sensors to determine when an engine misfire event is occurring and determine individual misfire events by monitoring the crankshaft rotational speed. A misfire is nothing more than a lack of combustion, which can be caused by poor fuel quality or metering, low compression, lack of spark or unmetered air entering the engine. Other possible causes such as uncommanded Exhaust Gas Recirculatin (EGR) flow can also cause a misfire. In the case of multiple cylinders misfiring, or the PCM not determining the specific cylinder misfiring, P0300 Multiple Cylinder Misfire will set.

Any time the engine is running, and the adaptive numerator has been successfully updated.

The threshold to set the fault is application specific; it is tied to the level of misfire that will cause emissions to increase to 1.5 times the standard or in some cases 1%. It is always a two trip fault above the calibrated RPM. It takes one fail to set a Pending Fault and two trips to set the MIL. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC Diagnose and repair any other active component or circuit DTCs before continuing with this procedure. Turn the ignition on. With the scan tool, select View DTCs. Copy DTC and Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, view the Misfire Monitor to see which cylinders are effected. NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to set or to show misfires on a particular cylinder. Are there excessive misfires shown or is the DTC pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. VISUAL INSPECTION NOTE: Anything that affects the speed of the crankshaft can cause a misfire DTC. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. NOTE: Misfires detected during a deceleration are indicators of mechanical concerns Visually inspect the engine for any of the following conditions: Worn serpentine belt. Refer to «BELT, SERPENTINE, DIAGNOSIS AND TESTING»(/jeep/grand-cherokee/wk2-2010-2013/remont/accessory-drive-belts/#engine-cooling-system) . Binding Engine-Driven accessories: A/C Compressor, P/S Pump, Water pump. Misalignment of the Water pump, P/S Pump and A/C Compressor pulleys. Corroded PCM power and ground circuits. Improper CKP, CMP, MAP and TP sensor mounting. Poor connector/terminal to component connection for CKP sensor, CMP sensor, MAP sensor, TP sensor, fuel injector, ignition coil, etc. Vacuum leaks. Restricted Exhaust system. Perform the CHECKING EXHAUST RESTRICTION diagnostic procedure. Refer to «CHECKING EXHAUST RESTRICTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__checking-exhaust-restriction) . Restricted Air Induction system. Internal engine component failures. Overfilled engine oil or transmission. Extremely out of balance tires or warped brake rotors. Were any of the above conditions present? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. IGNITION SYSTEM OPERATION WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Turn the ignition off. Remove the Ignition Coils. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Connect the Ignition Coil harness connectors. Disconnect the Fuel Injector harness connector of the cylinder being tested. Install a spark tester on the Ignition Coil. While cranking the engine observe the spark coming from the spark tester. NOTE: A crisp blue spark that is able to jump the gap of the spark tester should be generated at the coil on plug and at the end of the ignition wire. Is good spark present? Yes Go To 4 . No Go To 13 . NOTE: Connect the Fuel Injector harness connector before continuing.
4. SPARK PLUG Turn the ignition off. Remove the Spark Plug(s) in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Inspect the Spark Plug(s) for the following conditions: Cracks Carbon Tracking Foreign Material Gap size out of specifications Loose or broken electrode NOTE: Lightly tap the bottom of the spark plug on a solid surface. The electrode in the spark plug should not move. Were any of the above conditions present? Yes Replace the Spark Plug in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 .
5. FUEL PRESSURE CHECK WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Before continuing, visually and physically inspect the fuel delivery system for external leaks or damage. Repair/replace as necessary. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) to the fuel rail. Start the engine and observe the fuel pressure reading. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Choose a conclusion that best matches your fuel pressure reading. Within Specification Go To 6 . Below Specification Go To 11 . Above Specification Replace the fuel pressure regulator. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL PRESSURE LEAK DOWN Perform the Fuel Pressure Leak Down Test. Refer to «FUEL PRESSURE LEAK DOWN»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__fuel-pressure-leak-down) . Were any repairs made after performing the leak down test? Yes Testing complete. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. FUEL INJECTOR OPERATION WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. CAUTION: After each Fuel Injector actuation, start the engine to clean the cylinder of fuel. Failure to do so could cause engine damage. Open the Fuel System Isolation Valve. Start the engine and allow the fuel pressure to reach maximum pressure. Turn the ignition off. Ignition on, engine not running. Using the scan tool, actuate the Fuel Injector for the cylinder that indicated the misfire. Monitor the fuel pressure gauge. Does the fuel pressure gauge indicate a drop in fuel pressure? Yes Go To 8 . No Go To 9 . NOTE: Turn the ignition off, remove the Fuel Pressure Decay Tester and connect the fuel lines before continuing.
8. ENGINE MECHANICAL Check for any of the following conditions/mechanical problems: ENGINE VACUUM - must be at least 13 inches in neutral ENGINE VALVE TIMING - must be within specifications ENGINE COMPRESSION - must be within specifications CYLINDER LEAKAGE TEST - must be within specifications ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks. ENGINE PCV SYSTEM - must flow freely TORQUE CONVERTER STALL SPEED - must be within specifications POWER BRAKE BOOSTER - no internal vacuum leaks FUEL - must be free of contamination VALVE SPRINGS - cannot be weak or broken CAM LOBES - must not be worn excessively CAM SHAFTS - must not be worn or have excessive endplay Are there any engine mechanical problems? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
9. FUEL INJECTOR CONTROL Turn the ignition off. Disconnect the Fuel Injector harness connector of the misfiring cylinder. Ignition on, engine not running. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. Install an Injector Noid light. With the scan tool, actuate the Fuel Injector. Does the Noid light blink/flicker during the actuation? Yes Verify that there is good pin to terminal contact in the related Injector and the Powertrain Control Module connectors. Replace the Fuel Injector. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 10 .
10. INJECTOR CONTROL CIRCUIT Turn the ignition off. Disconnect the Fuel Injector harness connector. Disconnect the PCM harness connectors. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Injector Control circuit for an open, short to ground and short to voltage. Was a problem found with the Injector Control circuit? Yes Repair the excessive resistance or short in the Injector Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
11. FUEL SUPPLY LINE RESTRICTED WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Raise the vehicle on a hoist and disconnect the fuel pressure line at the fuel pump module. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) between the fuel supply line and the fuel pump module. Ignition on, engine not running. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Is the fuel pressure within specification? Yes Repair or replace fuel supply line as necessary. Refer to «TUBE(S), FUEL, DESCRIPTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 12 .
12. FUEL PUMP INLET STRAINER WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Is the Fuel Inlet Strainer plugged? Yes Replace the Fuel Pump Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Before continuing, check the Fuel Pump Module harness connector terminals for corrosion, damage or terminal push out. Make sure the ground circuit is functional. Repair as necessary. Replace the Fuel Pump Module. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
13. IGNITION COIL WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Disconnect the Ignition Coil harness connector. Using a 12-volt test light connected to 12-volts, probe the Ignition Coil Control circuit. Crank the engine for five seconds while observing the test light. NOTE: The primary resistance of the Ignition coil is 0.558 to 0.682 of an Ohm at 25° C (77° F). Does the test light brightly blink/flicker? Yes Verify that there is good pin to terminal contact in the related Coil and the Powertrain Control Module connectors. If OK, replace the Ignition Coil in accordance with the Service Information. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 14 .
14. COIL CONTROL CIRCUIT Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Coil Control circuit for an open, short to ground and short to voltage. Was a problem found with the Coil Control circuit? Yes Repair the Coil Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
15. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the related Sensor, Coil, Injector and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related Sensors, Coils, Injectors and the Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0304-CYLINDER 4 MISFIRE

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

Thoery of operation

The misfire detection monitor, software strategy in the Powertrain Control Module (PCM), is designed to detect an engine misfire. The PCM uses the Crankshaft (CKP) and Camshaft (CMP) sensors to determine when an engine misfire event is occurring and determine individual misfire events by monitoring the crankshaft rotational speed. A misfire is nothing more than a lack of combustion, which can be caused by poor fuel quality or metering, low compression, lack of spark or unmetered air entering the engine. Other possible causes such as uncommanded Exhaust Gas Recirculatin (EGR) flow can also cause a misfire. In the case of multiple cylinders misfiring, or the PCM not determining the specific cylinder misfiring, P0300 Multiple Cylinder Misfire will set.

Any time the engine is running, and the adaptive numerator has been successfully updated.

The threshold to set the fault is application specific; it is tied to the level of misfire that will cause emissions to increase to 1.5 times the standard or in some cases 1%. It is always a two trip fault above the calibrated RPM. It takes one fail to set a Pending Fault and two trips to set the MIL. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC Diagnose and repair any other active component or circuit DTCs before continuing with this procedure. Turn the ignition on. With the scan tool, select View DTCs. Copy DTC and Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, view the Misfire Monitor to see which cylinders are effected. NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to set or to show misfires on a particular cylinder. Are there excessive misfires shown or is the DTC pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. VISUAL INSPECTION NOTE: Anything that affects the speed of the crankshaft can cause a misfire DTC. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. NOTE: Misfires detected during a deceleration are indicators of mechanical concerns Visually inspect the engine for any of the following conditions: Worn serpentine belt. Refer to «BELT, SERPENTINE, DIAGNOSIS AND TESTING»(/jeep/grand-cherokee/wk2-2010-2013/remont/accessory-drive-belts/#engine-cooling-system) . Binding Engine-Driven accessories: A/C Compressor, P/S Pump, Water pump. Misalignment of the Water pump, P/S Pump and A/C Compressor pulleys. Corroded PCM power and ground circuits. Improper CKP, CMP, MAP and TP sensor mounting. Poor connector/terminal to component connection for CKP sensor, CMP sensor, MAP sensor, TP sensor, fuel injector, ignition coil, etc. Vacuum leaks. Restricted Exhaust system. Perform the CHECKING EXHAUST RESTRICTION diagnostic procedure. Refer to «CHECKING EXHAUST RESTRICTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__checking-exhaust-restriction) . Restricted Air Induction system. Internal engine component failures. Overfilled engine oil or transmission. Extremely out of balance tires or warped brake rotors. Were any of the above conditions present? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. IGNITION SYSTEM OPERATION WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Turn the ignition off. Remove the Ignition Coils. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Connect the Ignition Coil harness connectors. Disconnect the Fuel Injector harness connector of the cylinder being tested. Install a spark tester on the Ignition Coil. While cranking the engine observe the spark coming from the spark tester. NOTE: A crisp blue spark that is able to jump the gap of the spark tester should be generated at the coil on plug and at the end of the ignition wire. Is good spark present? Yes Go To 4 . No Go To 13 . NOTE: Connect the Fuel Injector harness connector before continuing.
4. SPARK PLUG Turn the ignition off. Remove the Spark Plug(s) in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Inspect the Spark Plug(s) for the following conditions: Cracks Carbon Tracking Foreign Material Gap size out of specifications Loose or broken electrode NOTE: Lightly tap the bottom of the spark plug on a solid surface. The electrode in the spark plug should not move. Were any of the above conditions present? Yes Replace the Spark Plug in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 .
5. FUEL PRESSURE CHECK WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Before continuing, visually and physically inspect the fuel delivery system for external leaks or damage. Repair/replace as necessary. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) to the fuel rail. Start the engine and observe the fuel pressure reading. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Choose a conclusion that best matches your fuel pressure reading. Within Specification Go To 6 . Below Specification Go To 11 . Above Specification Replace the fuel pressure regulator. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL PRESSURE LEAK DOWN Perform the Fuel Pressure Leak Down Test. Refer to «FUEL PRESSURE LEAK DOWN»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__fuel-pressure-leak-down) . Were any repairs made after performing the leak down test? Yes Testing complete. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. FUEL INJECTOR OPERATION WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. CAUTION: After each Fuel Injector actuation, start the engine to clean the cylinder of fuel. Failure to do so could cause engine damage. Open the Fuel System Isolation Valve. Start the engine and allow the fuel pressure to reach maximum pressure. Turn the ignition off. Ignition on, engine not running. Using the scan tool, actuate the Fuel Injector for the cylinder that indicated the misfire. Monitor the fuel pressure gauge. Does the fuel pressure gauge indicate a drop in fuel pressure? Yes Go To 8 . No Go To 9 . NOTE: Turn the ignition off, remove the Fuel Pressure Decay Tester and connect the fuel lines before continuing.
8. ENGINE MECHANICAL Check for any of the following conditions/mechanical problems: ENGINE VACUUM - must be at least 13 inches in neutral ENGINE VALVE TIMING - must be within specifications ENGINE COMPRESSION - must be within specifications CYLINDER LEAKAGE TEST - must be within specifications ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks. ENGINE PCV SYSTEM - must flow freely TORQUE CONVERTER STALL SPEED - must be within specifications POWER BRAKE BOOSTER - no internal vacuum leaks FUEL - must be free of contamination VALVE SPRINGS - cannot be weak or broken CAM LOBES - must not be worn excessively CAM SHAFTS - must not be worn or have excessive endplay Are there any engine mechanical problems? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
9. FUEL INJECTOR CONTROL Turn the ignition off. Disconnect the Fuel Injector harness connector of the misfiring cylinder. Ignition on, engine not running. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. Install an Injector Noid light. With the scan tool, actuate the Fuel Injector. Does the Noid light blink/flicker during the actuation? Yes Verify that there is good pin to terminal contact in the related Injector and the Powertrain Control Module connectors. Replace the Fuel Injector. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 10 .
10. INJECTOR CONTROL CIRCUIT Turn the ignition off. Disconnect the Fuel Injector harness connector. Disconnect the PCM harness connectors. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Injector Control circuit for an open, short to ground and short to voltage. Was a problem found with the Injector Control circuit? Yes Repair the excessive resistance or short in the Injector Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
11. FUEL SUPPLY LINE RESTRICTED WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Raise the vehicle on a hoist and disconnect the fuel pressure line at the fuel pump module. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) between the fuel supply line and the fuel pump module. Ignition on, engine not running. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Is the fuel pressure within specification? Yes Repair or replace fuel supply line as necessary. Refer to «TUBE(S), FUEL, DESCRIPTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 12 .
12. FUEL PUMP INLET STRAINER WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Is the Fuel Inlet Strainer plugged? Yes Replace the Fuel Pump Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Before continuing, check the Fuel Pump Module harness connector terminals for corrosion, damage or terminal push out. Make sure the ground circuit is functional. Repair as necessary. Replace the Fuel Pump Module. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
13. IGNITION COIL WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Disconnect the Ignition Coil harness connector. Using a 12-volt test light connected to 12-volts, probe the Ignition Coil Control circuit. Crank the engine for five seconds while observing the test light. NOTE: The primary resistance of the Ignition coil is 0.558 to 0.682 of an Ohm at 25° C (77° F). Does the test light brightly blink/flicker? Yes Verify that there is good pin to terminal contact in the related Coil and the Powertrain Control Module connectors. If OK, replace the Ignition Coil in accordance with the Service Information. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 14 .
14. COIL CONTROL CIRCUIT Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Coil Control circuit for an open, short to ground and short to voltage. Was a problem found with the Coil Control circuit? Yes Repair the Coil Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
15. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the related Sensor, Coil, Injector and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related Sensors, Coils, Injectors and the Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0305-CYLINDER 5 MISFIRE

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

Thoery of operation

The misfire detection monitor, software strategy in the Powertrain Control Module (PCM), is designed to detect an engine misfire. The PCM uses the Crankshaft (CKP) and Camshaft (CMP) sensors to determine when an engine misfire event is occurring and determine individual misfire events by monitoring the crankshaft rotational speed. A misfire is nothing more than a lack of combustion, which can be caused by poor fuel quality or metering, low compression, lack of spark or unmetered air entering the engine. Other possible causes such as uncommanded Exhaust Gas Recirculatin (EGR) flow can also cause a misfire. In the case of multiple cylinders misfiring, or the PCM not determining the specific cylinder misfiring, P0300 Multiple Cylinder Misfire will set.

Any time the engine is running, and the adaptive numerator has been successfully updated.

The threshold to set the fault is application specific; it is tied to the level of misfire that will cause emissions to increase to 1.5 times the standard or in some cases 1%. It is always a two trip fault above the calibrated RPM. It takes one fail to set a Pending Fault and two trips to set the MIL. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC Diagnose and repair any other active component or circuit DTCs before continuing with this procedure. Turn the ignition on. With the scan tool, select View DTCs. Copy DTC and Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, view the Misfire Monitor to see which cylinders are effected. NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to set or to show misfires on a particular cylinder. Are there excessive misfires shown or is the DTC pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. VISUAL INSPECTION NOTE: Anything that affects the speed of the crankshaft can cause a misfire DTC. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. NOTE: Misfires detected during a deceleration are indicators of mechanical concerns Visually inspect the engine for any of the following conditions: Worn serpentine belt. Refer to «BELT, SERPENTINE, DIAGNOSIS AND TESTING»(/jeep/grand-cherokee/wk2-2010-2013/remont/accessory-drive-belts/#engine-cooling-system) . Binding Engine-Driven accessories: A/C Compressor, P/S Pump, Water pump. Misalignment of the Water pump, P/S Pump and A/C Compressor pulleys. Corroded PCM power and ground circuits. Improper CKP, CMP, MAP and TP sensor mounting. Poor connector/terminal to component connection for CKP sensor, CMP sensor, MAP sensor, TP sensor, fuel injector, ignition coil, etc. Vacuum leaks. Restricted Exhaust system. Perform the CHECKING EXHAUST RESTRICTION diagnostic procedure. Refer to «CHECKING EXHAUST RESTRICTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__checking-exhaust-restriction) . Restricted Air Induction system. Internal engine component failures. Overfilled engine oil or transmission. Extremely out of balance tires or warped brake rotors. Were any of the above conditions present? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. IGNITION SYSTEM OPERATION WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Turn the ignition off. Remove the Ignition Coils. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Connect the Ignition Coil harness connectors. Disconnect the Fuel Injector harness connector of the cylinder being tested. Install a spark tester on the Ignition Coil. While cranking the engine observe the spark coming from the spark tester. NOTE: A crisp blue spark that is able to jump the gap of the spark tester should be generated at the coil on plug and at the end of the ignition wire. Is good spark present? Yes Go To 4 . No Go To 13 . NOTE: Connect the Fuel Injector harness connector before continuing.
4. SPARK PLUG Turn the ignition off. Remove the Spark Plug(s) in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Inspect the Spark Plug(s) for the following conditions: Cracks Carbon Tracking Foreign Material Gap size out of specifications Loose or broken electrode NOTE: Lightly tap the bottom of the spark plug on a solid surface. The electrode in the spark plug should not move. Were any of the above conditions present? Yes Replace the Spark Plug in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 .
5. FUEL PRESSURE CHECK WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Before continuing, visually and physically inspect the fuel delivery system for external leaks or damage. Repair/replace as necessary. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) to the fuel rail. Start the engine and observe the fuel pressure reading. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Choose a conclusion that best matches your fuel pressure reading. Within Specification Go To 6 . Below Specification Go To 11 . Above Specification Replace the fuel pressure regulator. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL PRESSURE LEAK DOWN Perform the Fuel Pressure Leak Down Test. Refer to «FUEL PRESSURE LEAK DOWN»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__fuel-pressure-leak-down) . Were any repairs made after performing the leak down test? Yes Testing complete. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. FUEL INJECTOR OPERATION WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. CAUTION: After each Fuel Injector actuation, start the engine to clean the cylinder of fuel. Failure to do so could cause engine damage. Open the Fuel System Isolation Valve. Start the engine and allow the fuel pressure to reach maximum pressure. Turn the ignition off. Ignition on, engine not running. Using the scan tool, actuate the Fuel Injector for the cylinder that indicated the misfire. Monitor the fuel pressure gauge. Does the fuel pressure gauge indicate a drop in fuel pressure? Yes Go To 8 . No Go To 9 . NOTE: Turn the ignition off, remove the Fuel Pressure Decay Tester and connect the fuel lines before continuing.
8. ENGINE MECHANICAL Check for any of the following conditions/mechanical problems: ENGINE VACUUM - must be at least 13 inches in neutral ENGINE VALVE TIMING - must be within specifications ENGINE COMPRESSION - must be within specifications CYLINDER LEAKAGE TEST - must be within specifications ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks. ENGINE PCV SYSTEM - must flow freely TORQUE CONVERTER STALL SPEED - must be within specifications POWER BRAKE BOOSTER - no internal vacuum leaks FUEL - must be free of contamination VALVE SPRINGS - cannot be weak or broken CAM LOBES - must not be worn excessively CAM SHAFTS - must not be worn or have excessive endplay Are there any engine mechanical problems? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
9. FUEL INJECTOR CONTROL Turn the ignition off. Disconnect the Fuel Injector harness connector of the misfiring cylinder. Ignition on, engine not running. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. Install an Injector Noid light. With the scan tool, actuate the Fuel Injector. Does the Noid light blink/flicker during the actuation? Yes Verify that there is good pin to terminal contact in the related Injector and the Powertrain Control Module connectors. Replace the Fuel Injector. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 10 .
10. INJECTOR CONTROL CIRCUIT Turn the ignition off. Disconnect the Fuel Injector harness connector. Disconnect the PCM harness connectors. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Injector Control circuit for an open, short to ground and short to voltage. Was a problem found with the Injector Control circuit? Yes Repair the excessive resistance or short in the Injector Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
11. FUEL SUPPLY LINE RESTRICTED WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Raise the vehicle on a hoist and disconnect the fuel pressure line at the fuel pump module. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) between the fuel supply line and the fuel pump module. Ignition on, engine not running. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Is the fuel pressure within specification? Yes Repair or replace fuel supply line as necessary. Refer to «TUBE(S), FUEL, DESCRIPTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 12 .
12. FUEL PUMP INLET STRAINER WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Is the Fuel Inlet Strainer plugged? Yes Replace the Fuel Pump Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Before continuing, check the Fuel Pump Module harness connector terminals for corrosion, damage or terminal push out. Make sure the ground circuit is functional. Repair as necessary. Replace the Fuel Pump Module. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
13. IGNITION COIL WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Disconnect the Ignition Coil harness connector. Using a 12-volt test light connected to 12-volts, probe the Ignition Coil Control circuit. Crank the engine for five seconds while observing the test light. NOTE: The primary resistance of the Ignition coil is 0.558 to 0.682 of an Ohm at 25° C (77° F). Does the test light brightly blink/flicker? Yes Verify that there is good pin to terminal contact in the related Coil and the Powertrain Control Module connectors. If OK, replace the Ignition Coil in accordance with the Service Information. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 14 .
14. COIL CONTROL CIRCUIT Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Coil Control circuit for an open, short to ground and short to voltage. Was a problem found with the Coil Control circuit? Yes Repair the Coil Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
15. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the related Sensor, Coil, Injector and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related Sensors, Coils, Injectors and the Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0306-CYLINDER 6 MISFIRE

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

Thoery of operation

The misfire detection monitor, software strategy in the Powertrain Control Module (PCM), is designed to detect an engine misfire. The PCM uses the Crankshaft (CKP) and Camshaft (CMP) sensors to determine when an engine misfire event is occurring and determine individual misfire events by monitoring the crankshaft rotational speed. A misfire is nothing more than a lack of combustion, which can be caused by poor fuel quality or metering, low compression, lack of spark or unmetered air entering the engine. Other possible causes such as uncommanded Exhaust Gas Recirculatin (EGR) flow can also cause a misfire. In the case of multiple cylinders misfiring, or the PCM not determining the specific cylinder misfiring, P0300 Multiple Cylinder Misfire will set.

Any time the engine is running, and the adaptive numerator has been successfully updated.

The threshold to set the fault is application specific; it is tied to the level of misfire that will cause emissions to increase to 1.5 times the standard or in some cases 1%. It is always a two trip fault above the calibrated RPM. It takes one fail to set a Pending Fault and two trips to set the MIL. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC Diagnose and repair any other active component or circuit DTCs before continuing with this procedure. Turn the ignition on. With the scan tool, select View DTCs. Copy DTC and Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, view the Misfire Monitor to see which cylinders are effected. NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to set or to show misfires on a particular cylinder. Are there excessive misfires shown or is the DTC pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. VISUAL INSPECTION NOTE: Anything that affects the speed of the crankshaft can cause a misfire DTC. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. NOTE: Misfires detected during a deceleration are indicators of mechanical concerns Visually inspect the engine for any of the following conditions: Worn serpentine belt. Refer to «BELT, SERPENTINE, DIAGNOSIS AND TESTING»(/jeep/grand-cherokee/wk2-2010-2013/remont/accessory-drive-belts/#engine-cooling-system) . Binding Engine-Driven accessories: A/C Compressor, P/S Pump, Water pump. Misalignment of the Water pump, P/S Pump and A/C Compressor pulleys. Corroded PCM power and ground circuits. Improper CKP, CMP, MAP and TP sensor mounting. Poor connector/terminal to component connection for CKP sensor, CMP sensor, MAP sensor, TP sensor, fuel injector, ignition coil, etc. Vacuum leaks. Restricted Exhaust system. Perform the CHECKING EXHAUST RESTRICTION diagnostic procedure. Refer to «CHECKING EXHAUST RESTRICTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__checking-exhaust-restriction) . Restricted Air Induction system. Internal engine component failures. Overfilled engine oil or transmission. Extremely out of balance tires or warped brake rotors. Were any of the above conditions present? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. IGNITION SYSTEM OPERATION WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Turn the ignition off. Remove the Ignition Coils. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Connect the Ignition Coil harness connectors. Disconnect the Fuel Injector harness connector of the cylinder being tested. Install a spark tester on the Ignition Coil. While cranking the engine observe the spark coming from the spark tester. NOTE: A crisp blue spark that is able to jump the gap of the spark tester should be generated at the coil on plug and at the end of the ignition wire. Is good spark present? Yes Go To 4 . No Go To 13 . NOTE: Connect the Fuel Injector harness connector before continuing.
4. SPARK PLUG Turn the ignition off. Remove the Spark Plug(s) in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Inspect the Spark Plug(s) for the following conditions: Cracks Carbon Tracking Foreign Material Gap size out of specifications Loose or broken electrode NOTE: Lightly tap the bottom of the spark plug on a solid surface. The electrode in the spark plug should not move. Were any of the above conditions present? Yes Replace the Spark Plug in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 .
5. FUEL PRESSURE CHECK WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Before continuing, visually and physically inspect the fuel delivery system for external leaks or damage. Repair/replace as necessary. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) to the fuel rail. Start the engine and observe the fuel pressure reading. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Choose a conclusion that best matches your fuel pressure reading. Within Specification Go To 6 . Below Specification Go To 11 . Above Specification Replace the fuel pressure regulator. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL PRESSURE LEAK DOWN Perform the Fuel Pressure Leak Down Test. Refer to «FUEL PRESSURE LEAK DOWN»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__fuel-pressure-leak-down) . Were any repairs made after performing the leak down test? Yes Testing complete. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. FUEL INJECTOR OPERATION WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. CAUTION: After each Fuel Injector actuation, start the engine to clean the cylinder of fuel. Failure to do so could cause engine damage. Open the Fuel System Isolation Valve. Start the engine and allow the fuel pressure to reach maximum pressure. Turn the ignition off. Ignition on, engine not running. Using the scan tool, actuate the Fuel Injector for the cylinder that indicated the misfire. Monitor the fuel pressure gauge. Does the fuel pressure gauge indicate a drop in fuel pressure? Yes Go To 8 . No Go To 9 . NOTE: Turn the ignition off, remove the Fuel Pressure Decay Tester and connect the fuel lines before continuing.
8. ENGINE MECHANICAL Check for any of the following conditions/mechanical problems: ENGINE VACUUM - must be at least 13 inches in neutral ENGINE VALVE TIMING - must be within specifications ENGINE COMPRESSION - must be within specifications CYLINDER LEAKAGE TEST - must be within specifications ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks. ENGINE PCV SYSTEM - must flow freely TORQUE CONVERTER STALL SPEED - must be within specifications POWER BRAKE BOOSTER - no internal vacuum leaks FUEL - must be free of contamination VALVE SPRINGS - cannot be weak or broken CAM LOBES - must not be worn excessively CAM SHAFTS - must not be worn or have excessive endplay Are there any engine mechanical problems? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
9. FUEL INJECTOR CONTROL Turn the ignition off. Disconnect the Fuel Injector harness connector of the misfiring cylinder. Ignition on, engine not running. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. Install an Injector Noid light. With the scan tool, actuate the Fuel Injector. Does the Noid light blink/flicker during the actuation? Yes Verify that there is good pin to terminal contact in the related Injector and the Powertrain Control Module connectors. Replace the Fuel Injector. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 10 .
10. INJECTOR CONTROL CIRCUIT Turn the ignition off. Disconnect the Fuel Injector harness connector. Disconnect the PCM harness connectors. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Injector Control circuit for an open, short to ground and short to voltage. Was a problem found with the Injector Control circuit? Yes Repair the excessive resistance or short in the Injector Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
11. FUEL SUPPLY LINE RESTRICTED WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Raise the vehicle on a hoist and disconnect the fuel pressure line at the fuel pump module. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) between the fuel supply line and the fuel pump module. Ignition on, engine not running. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Is the fuel pressure within specification? Yes Repair or replace fuel supply line as necessary. Refer to «TUBE(S), FUEL, DESCRIPTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 12 .
12. FUEL PUMP INLET STRAINER WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Is the Fuel Inlet Strainer plugged? Yes Replace the Fuel Pump Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Before continuing, check the Fuel Pump Module harness connector terminals for corrosion, damage or terminal push out. Make sure the ground circuit is functional. Repair as necessary. Replace the Fuel Pump Module. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
13. IGNITION COIL WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Disconnect the Ignition Coil harness connector. Using a 12-volt test light connected to 12-volts, probe the Ignition Coil Control circuit. Crank the engine for five seconds while observing the test light. NOTE: The primary resistance of the Ignition coil is 0.558 to 0.682 of an Ohm at 25° C (77° F). Does the test light brightly blink/flicker? Yes Verify that there is good pin to terminal contact in the related Coil and the Powertrain Control Module connectors. If OK, replace the Ignition Coil in accordance with the Service Information. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 14 .
14. COIL CONTROL CIRCUIT Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Coil Control circuit for an open, short to ground and short to voltage. Was a problem found with the Coil Control circuit? Yes Repair the Coil Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
15. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the related Sensor, Coil, Injector and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related Sensors, Coils, Injectors and the Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0307-CYLINDER 7 MISFIRE

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

Thoery of operation

The misfire detection monitor, software strategy in the Powertrain Control Module (PCM), is designed to detect an engine misfire. The PCM uses the Crankshaft (CKP) and Camshaft (CMP) sensors to determine when an engine misfire event is occurring and determine individual misfire events by monitoring the crankshaft rotational speed. A misfire is nothing more than a lack of combustion, which can be caused by poor fuel quality or metering, low compression, lack of spark or unmetered air entering the engine. Other possible causes such as uncommanded Exhaust Gas Recirculatin (EGR) flow can also cause a misfire. In the case of multiple cylinders misfiring, or the PCM not determining the specific cylinder misfiring, P0300 Multiple Cylinder Misfire will set.

Any time the engine is running, and the adaptive numerator has been successfully updated.

The threshold to set the fault is application specific; it is tied to the level of misfire that will cause emissions to increase to 1.5 times the standard or in some cases 1%. It is always a two trip fault above the calibrated RPM. It takes one fail to set a Pending Fault and two trips to set the MIL. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC Diagnose and repair any other active component or circuit DTCs before continuing with this procedure. Turn the ignition on. With the scan tool, select View DTCs. Copy DTC and Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, view the Misfire Monitor to see which cylinders are effected. NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to set or to show misfires on a particular cylinder. Are there excessive misfires shown or is the DTC pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. VISUAL INSPECTION NOTE: Anything that affects the speed of the crankshaft can cause a misfire DTC. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. NOTE: Misfires detected during a deceleration are indicators of mechanical concerns Visually inspect the engine for any of the following conditions: Worn serpentine belt. Refer to «BELT, SERPENTINE, DIAGNOSIS AND TESTING»(/jeep/grand-cherokee/wk2-2010-2013/remont/accessory-drive-belts/#engine-cooling-system) . Binding Engine-Driven accessories: A/C Compressor, P/S Pump, Water pump. Misalignment of the Water pump, P/S Pump and A/C Compressor pulleys. Corroded PCM power and ground circuits. Improper CKP, CMP, MAP and TP sensor mounting. Poor connector/terminal to component connection for CKP sensor, CMP sensor, MAP sensor, TP sensor, fuel injector, ignition coil, etc. Vacuum leaks. Restricted Exhaust system. Perform the CHECKING EXHAUST RESTRICTION diagnostic procedure. Refer to «CHECKING EXHAUST RESTRICTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__checking-exhaust-restriction) . Restricted Air Induction system. Internal engine component failures. Overfilled engine oil or transmission. Extremely out of balance tires or warped brake rotors. Were any of the above conditions present? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. IGNITION SYSTEM OPERATION WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Turn the ignition off. Remove the Ignition Coils. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Connect the Ignition Coil harness connectors. Disconnect the Fuel Injector harness connector of the cylinder being tested. Install a spark tester on the Ignition Coil. While cranking the engine observe the spark coming from the spark tester. NOTE: A crisp blue spark that is able to jump the gap of the spark tester should be generated at the coil on plug and at the end of the ignition wire. Is good spark present? Yes Go To 4 . No Go To 13 . NOTE: Connect the Fuel Injector harness connector before continuing.
4. SPARK PLUG Turn the ignition off. Remove the Spark Plug(s) in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Inspect the Spark Plug(s) for the following conditions: Cracks Carbon Tracking Foreign Material Gap size out of specifications Loose or broken electrode NOTE: Lightly tap the bottom of the spark plug on a solid surface. The electrode in the spark plug should not move. Were any of the above conditions present? Yes Replace the Spark Plug in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 .
5. FUEL PRESSURE CHECK WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Before continuing, visually and physically inspect the fuel delivery system for external leaks or damage. Repair/replace as necessary. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) to the fuel rail. Start the engine and observe the fuel pressure reading. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Choose a conclusion that best matches your fuel pressure reading. Within Specification Go To 6 . Below Specification Go To 11 . Above Specification Replace the fuel pressure regulator. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL PRESSURE LEAK DOWN Perform the Fuel Pressure Leak Down Test. Refer to «FUEL PRESSURE LEAK DOWN»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__fuel-pressure-leak-down) . Were any repairs made after performing the leak down test? Yes Testing complete. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. FUEL INJECTOR OPERATION WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. CAUTION: After each Fuel Injector actuation, start the engine to clean the cylinder of fuel. Failure to do so could cause engine damage. Open the Fuel System Isolation Valve. Start the engine and allow the fuel pressure to reach maximum pressure. Turn the ignition off. Ignition on, engine not running. Using the scan tool, actuate the Fuel Injector for the cylinder that indicated the misfire. Monitor the fuel pressure gauge. Does the fuel pressure gauge indicate a drop in fuel pressure? Yes Go To 8 . No Go To 9 . NOTE: Turn the ignition off, remove the Fuel Pressure Decay Tester and connect the fuel lines before continuing.
8. ENGINE MECHANICAL Check for any of the following conditions/mechanical problems: ENGINE VACUUM - must be at least 13 inches in neutral ENGINE VALVE TIMING - must be within specifications ENGINE COMPRESSION - must be within specifications CYLINDER LEAKAGE TEST - must be within specifications ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks. ENGINE PCV SYSTEM - must flow freely TORQUE CONVERTER STALL SPEED - must be within specifications POWER BRAKE BOOSTER - no internal vacuum leaks FUEL - must be free of contamination VALVE SPRINGS - cannot be weak or broken CAM LOBES - must not be worn excessively CAM SHAFTS - must not be worn or have excessive endplay Are there any engine mechanical problems? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
9. FUEL INJECTOR CONTROL Turn the ignition off. Disconnect the Fuel Injector harness connector of the misfiring cylinder. Ignition on, engine not running. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. Install an Injector Noid light. With the scan tool, actuate the Fuel Injector. Does the Noid light blink/flicker during the actuation? Yes Verify that there is good pin to terminal contact in the related Injector and the Powertrain Control Module connectors. Replace the Fuel Injector. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 10 .
10. INJECTOR CONTROL CIRCUIT Turn the ignition off. Disconnect the Fuel Injector harness connector. Disconnect the PCM harness connectors. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Injector Control circuit for an open, short to ground and short to voltage. Was a problem found with the Injector Control circuit? Yes Repair the excessive resistance or short in the Injector Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
11. FUEL SUPPLY LINE RESTRICTED WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Raise the vehicle on a hoist and disconnect the fuel pressure line at the fuel pump module. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) between the fuel supply line and the fuel pump module. Ignition on, engine not running. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Is the fuel pressure within specification? Yes Repair or replace fuel supply line as necessary. Refer to «TUBE(S), FUEL, DESCRIPTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 12 .
12. FUEL PUMP INLET STRAINER WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Is the Fuel Inlet Strainer plugged? Yes Replace the Fuel Pump Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Before continuing, check the Fuel Pump Module harness connector terminals for corrosion, damage or terminal push out. Make sure the ground circuit is functional. Repair as necessary. Replace the Fuel Pump Module. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
13. IGNITION COIL WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Disconnect the Ignition Coil harness connector. Using a 12-volt test light connected to 12-volts, probe the Ignition Coil Control circuit. Crank the engine for five seconds while observing the test light. NOTE: The primary resistance of the Ignition coil is 0.558 to 0.682 of an Ohm at 25° C (77° F). Does the test light brightly blink/flicker? Yes Verify that there is good pin to terminal contact in the related Coil and the Powertrain Control Module connectors. If OK, replace the Ignition Coil in accordance with the Service Information. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 14 .
14. COIL CONTROL CIRCUIT Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Coil Control circuit for an open, short to ground and short to voltage. Was a problem found with the Coil Control circuit? Yes Repair the Coil Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
15. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the related Sensor, Coil, Injector and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related Sensors, Coils, Injectors and the Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0308-CYLINDER 8 MISFIRE

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

Thoery of operation

The misfire detection monitor, software strategy in the Powertrain Control Module (PCM), is designed to detect an engine misfire. The PCM uses the Crankshaft (CKP) and Camshaft (CMP) sensors to determine when an engine misfire event is occurring and determine individual misfire events by monitoring the crankshaft rotational speed. A misfire is nothing more than a lack of combustion, which can be caused by poor fuel quality or metering, low compression, lack of spark or unmetered air entering the engine. Other possible causes such as uncommanded Exhaust Gas Recirculatin (EGR) flow can also cause a misfire. In the case of multiple cylinders misfiring, or the PCM not determining the specific cylinder misfiring, P0300 Multiple Cylinder Misfire will set.

Any time the engine is running, and the adaptive numerator has been successfully updated.

The threshold to set the fault is application specific; it is tied to the level of misfire that will cause emissions to increase to 1.5 times the standard or in some cases 1%. It is always a two trip fault above the calibrated RPM. It takes one fail to set a Pending Fault and two trips to set the MIL. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC Diagnose and repair any other active component or circuit DTCs before continuing with this procedure. Turn the ignition on. With the scan tool, select View DTCs. Copy DTC and Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. With the scan tool, view the Misfire Monitor to see which cylinders are effected. NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to set or to show misfires on a particular cylinder. Are there excessive misfires shown or is the DTC pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. VISUAL INSPECTION NOTE: Anything that affects the speed of the crankshaft can cause a misfire DTC. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. NOTE: Misfires detected during a deceleration are indicators of mechanical concerns Visually inspect the engine for any of the following conditions: Worn serpentine belt. Refer to «BELT, SERPENTINE, DIAGNOSIS AND TESTING»(/jeep/grand-cherokee/wk2-2010-2013/remont/accessory-drive-belts/#engine-cooling-system) . Binding Engine-Driven accessories: A/C Compressor, P/S Pump, Water pump. Misalignment of the Water pump, P/S Pump and A/C Compressor pulleys. Corroded PCM power and ground circuits. Improper CKP, CMP, MAP and TP sensor mounting. Poor connector/terminal to component connection for CKP sensor, CMP sensor, MAP sensor, TP sensor, fuel injector, ignition coil, etc. Vacuum leaks. Restricted Exhaust system. Perform the CHECKING EXHAUST RESTRICTION diagnostic procedure. Refer to «CHECKING EXHAUST RESTRICTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__checking-exhaust-restriction) . Restricted Air Induction system. Internal engine component failures. Overfilled engine oil or transmission. Extremely out of balance tires or warped brake rotors. Were any of the above conditions present? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. IGNITION SYSTEM OPERATION WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Turn the ignition off. Remove the Ignition Coils. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Connect the Ignition Coil harness connectors. Disconnect the Fuel Injector harness connector of the cylinder being tested. Install a spark tester on the Ignition Coil. While cranking the engine observe the spark coming from the spark tester. NOTE: A crisp blue spark that is able to jump the gap of the spark tester should be generated at the coil on plug and at the end of the ignition wire. Is good spark present? Yes Go To 4 . No Go To 13 . NOTE: Connect the Fuel Injector harness connector before continuing.
4. SPARK PLUG Turn the ignition off. Remove the Spark Plug(s) in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Inspect the Spark Plug(s) for the following conditions: Cracks Carbon Tracking Foreign Material Gap size out of specifications Loose or broken electrode NOTE: Lightly tap the bottom of the spark plug on a solid surface. The electrode in the spark plug should not move. Were any of the above conditions present? Yes Replace the Spark Plug in accordance with the Service Information. Refer to «SPARK PLUG, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 5 .
5. FUEL PRESSURE CHECK WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Before continuing, visually and physically inspect the fuel delivery system for external leaks or damage. Repair/replace as necessary. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) to the fuel rail. Start the engine and observe the fuel pressure reading. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Choose a conclusion that best matches your fuel pressure reading. Within Specification Go To 6 . Below Specification Go To 11 . Above Specification Replace the fuel pressure regulator. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
6. FUEL PRESSURE LEAK DOWN Perform the Fuel Pressure Leak Down Test. Refer to «FUEL PRESSURE LEAK DOWN»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#driveability-gas-non-dtc-based-diagnostics__fuel-pressure-leak-down) . Were any repairs made after performing the leak down test? Yes Testing complete. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. FUEL INJECTOR OPERATION WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. CAUTION: After each Fuel Injector actuation, start the engine to clean the cylinder of fuel. Failure to do so could cause engine damage. Open the Fuel System Isolation Valve. Start the engine and allow the fuel pressure to reach maximum pressure. Turn the ignition off. Ignition on, engine not running. Using the scan tool, actuate the Fuel Injector for the cylinder that indicated the misfire. Monitor the fuel pressure gauge. Does the fuel pressure gauge indicate a drop in fuel pressure? Yes Go To 8 . No Go To 9 . NOTE: Turn the ignition off, remove the Fuel Pressure Decay Tester and connect the fuel lines before continuing.
8. ENGINE MECHANICAL Check for any of the following conditions/mechanical problems: ENGINE VACUUM - must be at least 13 inches in neutral ENGINE VALVE TIMING - must be within specifications ENGINE COMPRESSION - must be within specifications CYLINDER LEAKAGE TEST - must be within specifications ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks. ENGINE PCV SYSTEM - must flow freely TORQUE CONVERTER STALL SPEED - must be within specifications POWER BRAKE BOOSTER - no internal vacuum leaks FUEL - must be free of contamination VALVE SPRINGS - cannot be weak or broken CAM LOBES - must not be worn excessively CAM SHAFTS - must not be worn or have excessive endplay Are there any engine mechanical problems? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
9. FUEL INJECTOR CONTROL Turn the ignition off. Disconnect the Fuel Injector harness connector of the misfiring cylinder. Ignition on, engine not running. NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. Install an Injector Noid light. With the scan tool, actuate the Fuel Injector. Does the Noid light blink/flicker during the actuation? Yes Verify that there is good pin to terminal contact in the related Injector and the Powertrain Control Module connectors. Replace the Fuel Injector. Refer to «INJECTOR(S), FUEL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 10 .
10. INJECTOR CONTROL CIRCUIT Turn the ignition off. Disconnect the Fuel Injector harness connector. Disconnect the PCM harness connectors. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Injector Control circuit for an open, short to ground and short to voltage. Was a problem found with the Injector Control circuit? Yes Repair the excessive resistance or short in the Injector Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
11. FUEL SUPPLY LINE RESTRICTED WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Raise the vehicle on a hoist and disconnect the fuel pressure line at the fuel pump module. Install the Fuel Pressure Decay Tester (special tool #8978A, Decay Tool, Fuel) between the fuel supply line and the fuel pump module. Ignition on, engine not running. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. NOTE: Fuel pressure specification: For 3.6L is 400 kPa +/- 14 kPa (58 psi +/- 2 psi) For 5.7L is 407 kPa +/- 34 kPa (59 psi +/- 5 psi) Is the fuel pressure within specification? Yes Repair or replace fuel supply line as necessary. Refer to «TUBE(S), FUEL, DESCRIPTION»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 12 .
12. FUEL PUMP INLET STRAINER WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury. Turn the ignition off. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Is the Fuel Inlet Strainer plugged? Yes Replace the Fuel Pump Inlet Strainer. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Before continuing, check the Fuel Pump Module harness connector terminals for corrosion, damage or terminal push out. Make sure the ground circuit is functional. Repair as necessary. Replace the Fuel Pump Module. Refer to «MODULE, FUEL PUMP, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
13. IGNITION COIL WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Disconnect the Ignition Coil harness connector. Using a 12-volt test light connected to 12-volts, probe the Ignition Coil Control circuit. Crank the engine for five seconds while observing the test light. NOTE: The primary resistance of the Ignition coil is 0.558 to 0.682 of an Ohm at 25° C (77° F). Does the test light brightly blink/flicker? Yes Verify that there is good pin to terminal contact in the related Coil and the Powertrain Control Module connectors. If OK, replace the Ignition Coil in accordance with the Service Information. Refer to «COIL, IGNITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 14 .
14. COIL CONTROL CIRCUIT Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Check the Coil Control circuit for an open, short to ground and short to voltage. Was a problem found with the Coil Control circuit? Yes Repair the Coil Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
15. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the related Sensor, Coil, Injector and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related Sensors, Coils, Injectors and the Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

Scheme 186

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The Crankshaft Position System variation learn feature is used to calculate reference errors caused by slight tolerance variations in the crankshaft, tone wheel and the crankshaft position sensors. The calculated error allows the Powertrain Control Module (PCM) to accurately compensate for reference variations. The Crankshaft Position System variation compensating values are learned and stored in the PCM memory during a decel fuel shutoff event. If the actual crankshaft variation is not within the Crankshaft Position System's compensating values stored in the PCM, DTC P0300 may set. If the CKP System variation values are not stored in the PCM memory, DTC P0315 sets.

Under closed throttle decel and A/C off. ECT above 75° C (167° F). Engine start time is greater than 50 seconds.

One of the CKP sensor target windows has more than 2% variance from the reference. One Trip Fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DTC Turn the ignition on. With the scan tool, select View DTCs. Copy DTC and Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set. NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions. It may take up to three 60-40 MPH decels in order for this DTC to set. Does the DTC reset while cranking or during the test drive? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. WIRE HARNESS INSPECTION Turn the ignition off. Visually inspect the CKP wire harness. Look for any chafed, pierced, pinched, or partially broken wires. Visually inspect the CKP wire harness connectors. Look for broken, bent, pushed out, or corroded terminals. Verify that there is good pin to terminal contact in the Crank Position Sensor and Powertrain Control Module connectors. Make sure the Crankshaft Position Sensor is properly installed and the mounting bolt(s) are torqued to the proper specification. Were any of the above conditions present? Yes Repair as necessary Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. TONE WHEEL/FLEX PLATE INSPECTION Remove the Crankshaft Position Sensor. Refer to «SENSOR, CRANKSHAFT POSITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Inspect the Tone Wheel/Flex Plate slots for damage, foreign material, or excessive movement. Were any problems found? Yes Repair or replace the Tone Wheel/Flex Plate as necessary. Refer to «CRANKSHAFT, REMOVAL, 3.6L»(/jeep/grand-cherokee/wk2-2010-2013/remont/mechanical/#36l-engine-service-information) , or «CRANKSHAFT, REMOVAL, 5.7L»(/jeep/grand-cherokee/wk2-2010-2013/remont/mechanical/#57l-engine-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. CRANKSHAFT POSITION SENSOR If there are no possible causes remaining, view repair. Repair Replace the Crankshaft Position Sensor. Refer to «SENSOR, CRANKSHAFT POSITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0325-KNOCK SENSOR 1 CIRCUIT

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

Knock is the spontaneous auto-ignition of the remaining fuel/air mixture in the engine combustion chamber that occurs after normal combustion has started. It can occur under extreme vehicle operating conditions such as high engine temperature, high MAP, low humidity and heavy loads to the engine. Knock is caused by excessive spark advance for the given engine operating conditions. Severe, continuous knock may be caused by carbon deposits, bad gasoline and/or low octane fuel. Avoiding light audible knock is important for customer satisfaction while preventing excessive knock is important to protect engine components. The output voltage from the knock circuit represents the strength of the engine knock and is read by the engine controller. The knock system output voltage is not zero due to engine background noise, even when knock is not present. When the engine is operated under high load conditions where knock is possible, the knock voltage is tested to decide if it exceeds the knock voltage threshold. Knock has occurred when the knock voltage is at or above this knock threshold. When knock is detected a calibrated short term knock spark retard to be subtracted from the spark advance is calculated. The amount of retarded spark advance is based off a calibrated severity of the knock event. This retarded spark advance is used in the next ignition event to prevent further knock events. If knock continues, an additional amount of short term spark advance retard is added. When knock stops, short term knock spark retard is eliminated, the long term knock spark retard is reduced by a calibrated amount to recover some previously retarded spark advance. This decreases spark retard to improve engine performance.

This monitor runs above 2000 RPM, under open throttle conditions. The Knock diagnostic does not run at idle or during decelerations. The high voltage test runs all the times the engine is running.

The Powertrain Control Module (PCM) detects that the Knock Sensor input voltage is: Above 4.0 Volts, less than or equal to 1.0 Volt with engine RPM at or above 2200 or equal to 0.0 Volts with engine RPM below 2200. Two Trip Fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 187

Scheme 188

Scheme 189

Scheme 190

Scheme 191

1. ACTIVE DTC Start the engine. Allow the engine to reach normal operating temperature. With the scan tool, select View DTCs. NOTE: It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data. Is the DTC Active or Pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. (K42) KNOCK SENSOR NO. 1 SIGNAL CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Disconnect the Knock Sensor harness connector. Disconnect the C2 PCM harness connector. Ignition on, engine not running. Measure the voltage on the (K42) Knock Sensor No. 1 Signal circuit in the Knock Sensor harness connector. Is there any voltage present? Yes Repair the short to voltage in the (K42) Knock Sensor No. 1 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. (K42) KNOCK SENSOR NO. 1 SIGNAL CIRCUIT OPEN Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K42) Knock Sensor No. 1 Signal circuit from the Knock Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 4 . No Repair the open in the (K42) Knock Sensor No. 1 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
4. (K942) KNOCK SENSOR NO. 1 RETURN CIRCUIT OPEN Measure the resistance of the (K942) Knock Sensor No. 1 Return circuit from the Knock Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 5 . No Repair the open in the (K942) Knock Sensor No. 1 Return circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K42) KNOCK SENSOR NO. 1 SIGNAL CIRCUIT SHORTED TO THE (K942) KNOCK SENSOR NO. 1 RETURN CIRCUIT Measure the resistance between the (K42) Knock Sensor No. 1 Signal circuit and the (K942) Knock Sensor No. 1 Return circuit in the Knock Sensor harness connector. Is the resistance below 100 Ohms? Yes Repair the short between the (K42) Knock Sensor No. 1 Signal circuit and the (K942) Knock Sensor No. 1 Return circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 6 .
6. (K42) KNOCK SENSOR NO. 1 SIGNAL CIRCUIT SHORTED TO GROUND Measure the resistance between ground and the (K42) Knock Sensor No. 1 Signal circuit in the Knock Sensor harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K42) Knock Sensor No. 1 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. KNOCK SENSOR 1 Turn the ignition off. Verify that there is good pin to terminal contact at the Knock Sensor and the Powertrain Control Module connectors. If no problems were found in the connectors, replace the Knock Sensor 1. Refer to «SENSOR, KNOCK, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Connect the Powertrain Control Module (PCM) harness connector. Turn the ignition on. With the scan tool, clear DTCs. Start the engine and allow it to reach normal operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to reset. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 8 . No Test complete. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Knock Sensor 1 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Were any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0330-KNOCK SENSOR 2 CIRCUIT

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

Knock is the spontaneous auto-ignition of the remaining fuel/air mixture in the engine combustion chamber that occurs after normal combustion has started. It can occur under extreme vehicle operating conditions such as high engine temperature, high MAP, low humidity and heavy loads to the engine. Knock is caused by excessive spark advance for the given engine operating conditions. Severe, continuous knock may be caused by carbon deposits, bad gasoline and/or low octane fuel. Avoiding light audible knock is important for customer satisfaction while preventing excessive knock is important to protect engine components. The output voltage from the knock circuit represents the strength of the engine knock and is read by the engine controller. The knock system output voltage is not zero due to engine background noise, even when knock is not present. When the engine is operated under high load conditions where knock is possible, the knock voltage is tested to decide if it exceeds the knock voltage threshold. Knock has occurred when the knock voltage is at or above this knock threshold. When knock is detected a calibrated short term knock spark retard to be subtracted from the spark advance is calculated. The amount of retarded spark advance is based off a calibrated severity of the knock event. This retarded spark advance is used in the next ignition event to prevent further knock events. If knock continues, an additional amount of short term spark advance retard is added. When knock stops, short term knock spark retard is eliminated, the long term knock spark retard is reduced by a calibrated amount to recover some previously retarded spark advance. This decreases spark retard to improve engine performance.

This monitor runs above 2000 RPM, under open throttle conditions. The Knock diagnostic does not run at idle or during decelerations. The high voltage test runs all the times the engine is running.

The Powertrain Control Module (PCM) detects that the Knock Sensor input voltage is: Above 4.0 Volts, less than or equal to 1.0 Volt with engine RPM at or above 2200 or equal to 0.0 Volts with engine RPM below 2200. Two Trip Fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 192

Scheme 193

1. ACTIVE DTC Start the engine. Allow the engine to reach normal operating temperature. With the scan tool, select View DTCs. NOTE: It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data. Is the DTC Active or Pending at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. (K242) KNOCK SENSOR NO. 2 SIGNAL CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Disconnect the No. 2 Knock Sensor harness connector. Disconnect the C2 PCM harness connector. Ignition on, engine not running. Measure the voltage on the (K242) Knock Sensor No. 2 Signal circuit in the Knock Sensor harness connector. Is there any voltage present? Yes Repair the short to voltage in the (K242) Knock Sensor No. 2 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 3 .
3. (K242) KNOCK SENSOR NO. 2 SIGNAL CIRCUIT OPEN Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K242) Knock Sensor No. 2 Signal circuit from the Knock Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 4 . No Repair the open in the (K242) Knock Sensor No. 2 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
4. (K924) KNOCK SENSOR NO. 2 RETURN CIRCUIT OPEN Measure the resistance of the (K924) Knock Sensor No. 2 Return circuit from the Knock Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 5 . No Repair the open in the (K924) Knock Sensor No. 2 Return circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K242) KNOCK SENSOR NO. 2 SIGNAL CIRCUIT SHORTED TO THE (K924) KNOCK SENSOR NO. 2 RETURN CIRCUIT Measure the resistance between the (K242) Knock Sensor No. 2 Signal circuit and the (K924) Knock Sensor No. 2 Return circuit in the Knock Sensor harness connector. Is the resistance below 100 Ohms? Yes Repair the short between the (K242) Knock Sensor No. 2 Signal circuit and the (K924) Knock Sensor No. 2 Return circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 6 .
6. (K242) KNOCK SENSOR NO. 2 SIGNAL CIRCUIT SHORTED TO GROUND Measure the resistance between ground and the (K242) Knock Sensor No. 2 Signal circuit in the Knock Sensor harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K242) Knock Sensor No. 2 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. KNOCK SENSOR 2 Turn the ignition off. If no problems were found in the connectors, replace the Knock Sensor 2. Refer to «SENSOR, KNOCK, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Connect the Powertrain Control Module (PCM) harness connector. Turn the ignition on. With the scan tool, clear DTCs. Start the engine and allow it to reach normal operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to reset. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To 8 . No Test complete. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
8. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Knock Sensor 2 and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Perform any Technical Service Bulletins that may apply. Were any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to «SENSOR, KNOCK, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

Scheme 194

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The Crankshaft Position (CKP) sensor circuits consist of a Powertrain Control Module (PCM) supplied 5 Volt reference circuit, low reference circuit and an output signal circuit. The CKP sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes between the peaks and valleys of a reluctor wheel on the crankshaft. Each tooth on the reluctor wheel is spaced with missing teeth for the reference gap. The CKP sensor produces an ON/OFF DC voltage of varying frequency, reference output pulses per crankshaft revolution. The frequency of the CKP sensor output depends on the velocity of the crankshaft. The CKP sensor sends a digital signal, which represents an image of the crankshaft reluctor wheel, to the PCM as each tooth on the wheel rotates past the CKP sensor. The PCM uses each CKP signal pulse to determine crankshaft speed and decodes the crankshaft reluctor wheel reference gap to identify crankshaft position. This information is then used to sequence the ignition timing and fuel injection events for the engine. The PCM also uses CKP sensor output information to determine the crankshaft relative position to the camshaft, to detect cylinder misfire and to control the CMP actuator if equipped.

Engine cranking.

No CKP signal is present during engine cranking and at least eight camshaft position sensor signals have occurred. One Trip Fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 195

Scheme 196

Scheme 197

Scheme 198

Scheme 199

Scheme 200

Scheme 201

Scheme 202

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) Crank the engine. Ignition on, engine not running. With the scan tool, read the active DTCs. Is the DTC Active at this time? Yes Go To 2 . No Go To 14 .
2. (K855) 5 VOLT SUPPLY CIRCUIT Turn the ignition off. Disconnect the CKP Sensor harness connector. Ignition on, engine not running. Measure the voltage on the (K855) 5 Volt Supply circuit in the CKP Sensor harness connector. Is the voltage between 4.5 and 5.2 Volts? Yes Go To 3 . No Go To 10 .
3. (K24) CKP SIGNAL CIRCUIT Measure the voltage on the (K24) CKP Signal circuit in the CKP Sensor harness connector. NOTE: The sensor voltage should be approximately 5.0 Volts (plus or minus.1 of a Volt) with the connector disconnected. Is the voltage as described above? Yes Go To 4 . No Go To 7 .
4. (K900) SENSOR GROUND CIRCUIT OPEN Turn the ignition off. Disconnect the C2 PCM harness connector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K900) Sensor ground circuit from the CKP Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 5 . No Repair the open in the (K900) Sensor ground circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K24) CKP SIGNAL CIRCUIT SHORTED TO THE (K855) 5 VOLT SUPPLY CIRCUIT Measure the resistance between the (K24) CKP Signal circuit and the (K855) 5 Volt Supply circuit in the CKP Sensor harness connector. Is the resistance below 5.0 Ohms? Yes Repair the short between the (K24) CKP Signal circuit and the (K855) 5 Volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 6 .
6. CRANKSHAFT POSITION SENSOR NOTE: Inspect the slots on the flywheel for damage. If a problem is found repair as necessary. Repair Verify that there is good pin to terminal contact in the Crank Position Sensor and Powertrain Control Module connectors. Replace the Crank Position Sensor if no problems were found with the connectors. Refer to «SENSOR, CRANKSHAFT POSITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K24) CKP SIGNAL CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Disconnect the C2 PCM harness connector. Ignition on, engine not running. Measure the voltage on the (K24) CKP Signal circuit in the CKP Sensor harness connector. Is there any voltage present? Yes Repair the short to voltage in the (K24) CKP Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. (K24) CKP SIGNAL CIRCUIT OPEN Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K24) CKP Signal circuit from the CKP Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 9 . No Repair the open in the (K24) CKP Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
9. (K24) CKP SIGNAL CIRCUIT SHORTED TO GROUND Measure the resistance between ground and the (K24) CKP Signal circuit in the CKP Sensor harness connector. Is the resistance below 5.0 Ohms? Yes Repair the short to ground in the (K24) CKP Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 13 .
10. (K855) 5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Disconnect the C2 PCM harness connector. Ignition on, engine not running. Measure the voltage on the (K855) 5 Volt Supply circuit in the CKP Sensor harness connector. Is there any voltage present? Yes Repair the short to voltage in the (K855) 5 Volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 11 .
11. (K855) 5 VOLT SUPPLY CIRCUIT OPEN Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K855) 5 Volt Supply circuit from the CKP Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 12 . No Repair the open in the (K855) 5 Volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
12. (K855) 5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND Measure the resistance between ground and the (K855) 5 Volt Supply circuit in the CKP Sensor harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K855) 5 Volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 13 .
13. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the related Sensor and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related Sensor and the Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
14. ERRATIC CKP SENSOR SIGNAL Turn the ignition off. With a lab scope backprobe the (K24) CKP Signal circuit in the CKP harness connector. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Ignition on, engine not running. Wiggle the related wire harness and lightly tap on the Crank Position Sensor. Observe the lab scope screen. Look for any pulses generated by the CKP Sensor. Allow the engine to idle. Observe the lab scope screen. Did the CKP Sensor generate any erratic pulses? Yes Verify that there is good pin to terminal contact in the Crank Position Sensor and Powertrain Control Module connectors. Replace the Crank Position Sensor if no issues were found with the connectors. Refer to «SENSOR, CRANKSHAFT POSITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
15. ERRATIC CMP SIGNAL Turn the ignition off. With a lab scope backprobe the (K44) Cam Position Sensor (CMP) Signal circuit in the CMP harness connector. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Ignition on, engine not running. Wiggle the related wire harness and lightly tap on the Cam Position Sensor. Observe the lab scope screen. Look for any pulses generated by the CMP Sensor. Allow the engine to idle. Observe the lab scope screen. NOTE: On multiple CMP sensor engines repeat this test for the other signal circuits Did the CMP Sensor generate any pulses? Yes Verify that there is good pin to terminal contact in the CMP Sensor and Powertrain Control Module connectors. Replace the Camshaft Position Sensor if no issues were found with the connectors. Refer to «SENSOR, CAMSHAFT POSITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Test complete, the conditions that set this DTC are not present at this time. Perform the INTERMITTENT CONDITION diagnostic procedure for further assistance. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

Scheme 203

Note. The CMP sensor is a dual read sensor reading both camshafts of it's correlating bank.

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

The Crankshaft Position (CKP) Sensor circuits consist of a Powertrain Control Module (PCM) supplied 5 Volt reference circuit, low reference circuit and an output signal circuit. The CKP Sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes between the peaks and valleys of a reluctor wheel on the Crankshaft. Each tooth on the reluctor wheel is spaced with missing teeth for the reference gap. The CKP Sensor produces an ON/OFF DC voltage of varying frequency, reference output pulses per Crankshaft revolution. The frequency of the CKP Sensor output depends on the velocity of the crankshaft. The CKP Sensor sends a digital signal, which represents an image of the Crankshaft reluctor wheel, to the PCM as each tooth on the wheel rotates past the CKP Sensor. The PCM uses each CKP signal pulse to determine Crankshaft speed and decodes the Crankshaft reluctor wheel reference gap to identify Crankshaft position. This information is then used to sequence the ignition timing and fuel injection events for the engine. The PCM also uses CKP Sensor output information to determine the Crankshaft relative position to the Camshaft, to detect cylinder misfire and to control the CMP actuator if equipped.

With the engine cranking or running

No CKP signal is present during engine cranking and at least eight Camshaft Position Sensor signals have occurred. One Trip Fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) Crank the engine. Ignition on, engine not running. With the scan tool, read the active DTCs. Is the DTC Active at this time? Yes Go To 2 . No Go To 14 .
2. (K855) 5 VOLT SUPPLY CIRCUIT Turn the ignition off. Disconnect the CKP Sensor harness connector. Ignition on, engine not running. Measure the voltage on the (K855) 5 Volt Supply circuit in the CKP Sensor harness connector. Is the voltage between 4.5 and 5.2 Volts? Yes Go To 3 . No Go To 10 .
3. (K24) CKP SIGNAL CIRCUIT Measure the voltage on the (K24) CKP Signal circuit in the CKP Sensor harness connector. NOTE: The sensor voltage should be approximately 5.0 Volts (plus or minus.1 of a Volt) with the connector disconnected. Is the voltage as described above? Yes Go To 4 . No Go To 7 .
4. (K900) SENSOR GROUND CIRCUIT OPEN Turn the ignition off. Disconnect the C2 PCM harness connector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K900) Sensor ground circuit from the CKP Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 5 . No Repair the open in the (K900) Sensor ground circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. (K24) CKP SIGNAL CIRCUIT SHORTED TO THE (K855) 5 VOLT SUPPLY CIRCUIT Measure the resistance between the (K24) CKP Signal circuit and the (K855) 5 Volt Supply circuit in the CKP Sensor harness connector. Is the resistance below 5.0 Ohms? Yes Repair the short between the (K24) CKP Signal circuit and the (K855) 5 Volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 6 .
6. CRANKSHAFT POSITION SENSOR NOTE: Inspect the slots on the flywheel for damage. If a problem is found repair as necessary. Repair Verify that there is good pin to terminal contact in the Crank Position Sensor and Powertrain Control Module connectors. Replace the Crank Position Sensor if no problems were found with the connectors. Refer to «SENSOR, CRANKSHAFT POSITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
7. (K24) CKP SIGNAL CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Disconnect the C2 PCM harness connector. Ignition on, engine not running. Measure the voltage on the (K24) CKP Signal circuit in the CKP Sensor harness connector. Is there any voltage present? Yes Repair the short to voltage in the (K24) CKP Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 8 .
8. (K24) CKP SIGNAL CIRCUIT OPEN Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K24) CKP Signal circuit from the CKP Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 9 . No Repair the open in the (K24) CKP Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
9. (K24) CKP SIGNAL CIRCUIT SHORTED TO GROUND Measure the resistance between ground and the (K24) CKP Signal circuit in the CKP Sensor harness connector. Is the resistance below 5.0 Ohms? Yes Repair the short to ground in the (K24) CKP Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 13 .
10. (K855) 5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Disconnect the C2 PCM harness connector. Ignition on, engine not running. Measure the voltage on the (K855) 5 Volt Supply circuit in the CKP Sensor harness connector. Is there any voltage present? Yes Repair the short to voltage in the (K855) 5 Volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 11 .
11. (K855) 5 VOLT SUPPLY CIRCUIT OPEN Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance of the (K855) 5 Volt Supply circuit from the CKP Sensor harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Is the resistance below 5.0 Ohms? Yes Go To 12 . No Repair the open in the (K855) 5 Volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
12. (K855) 5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND Measure the resistance between ground and the (K855) 5 Volt Supply circuit in the CKP Sensor harness connector. Is the resistance below 100 Ohms? Yes Repair the short to ground in the (K855) 5 Volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 13 .
13. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the related Sensor and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related Sensor and the Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to «MODULE, POWERTRAIN CONTROL, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/communication-devices/#electronic-control-modules-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
14. ERRATIC CKP SENSOR SIGNAL Turn the ignition off. With a lab scope backprobe the (K24) CKP Signal circuit in the CKP harness connector. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Ignition on, engine not running. Wiggle the related wire harness and lightly tap on the Crank Position Sensor. Observe the lab scope screen. Look for any pulses generated by the CKP Sensor. Allow the engine to idle. Observe the lab scope screen. Did the CKP Sensor generate any erratic pulses? Yes Verify that there is good pin to terminal contact in the Crank Position Sensor and Powertrain Control Module connectors. Replace the Crank Position Sensor if no issues were found with the connectors. Refer to «SENSOR, CRANKSHAFT POSITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 15 .
15. ERRATIC CMP SIGNAL Turn the ignition off. With a lab scope backprobe the (K44) Cam Position Sensor (CMP) Signal circuit in the CMP harness connector. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Ignition on, engine not running. Wiggle the related wire harness and lightly tap on the Cam Position Sensor. Observe the lab scope screen. Look for any pulses generated by the CMP Sensor. Allow the engine to idle. Observe the lab scope screen. NOTE: On multiple CMP sensor engines repeat this test for the other signal circuits Did the CMP Sensor generate any pulses? Yes Verify that there is good pin to terminal contact in the CMP Sensor and Powertrain Control Module connectors. Replace the Camshaft Position Sensor if no issues were found with the connectors. Refer to «SENSOR, CAMSHAFT POSITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Test complete, the conditions that set this DTC are not present at this time. Perform the INTERMITTENT CONDITION diagnostic procedure for further assistance. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

P0339-CRANKSHAFT POSITION SENSOR INTERMITTENT - 3.6L

Note. The CMP sensor is a dual read sensor reading both camshafts of it's correlating bank.

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

While cranking the engine and with the engine running.

When the CKP Sensor failure counter reaches 20. One Trip Fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) Turn the ignition on. Using the scan tool, read DTCs. Copy DTC and Freeze Frame information. Start the engine and allow it to reach operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. NOTE: Attempt to operate the vehicle under conditions similar to which the DTC was set. NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to set. With the scan tool, read the active DTCs. Is the DTC Active at this time? Yes Go To 2 . No Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to «INTERMITTENT CONDITION»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
2. CHECKING CRANKSHAFT POSITION SENSOR SIGNAL WITH A LAB SCOPE Turn the ignition off. With a lab scope probe, backprobe the (K24) CKP Signal circuit in the Sensor harness connector. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Ignition on, engine not running. Observe the lab scope screen. Start the engine. Observe the lab scope screen. Are there any irregular or missing signals? Yes Go To 3 . No Go To 8 .
3. WIRE HARNESS INSPECTION Turn the ignition off. Visually inspect the related wire harness, including the ground circuit. Look for any chafed, pierced, pinched or partially broken wires. Visually inspect the related wire harness connectors. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Crankshaft Position Sensor and the Powertrain Control Module connectors. Make sure the Crankshaft Position Sensor and the Camshaft Position Sensor are properly installed and the mounting bolt(s) are torqued to the proper specification. Perform any TSBs that may apply. Were any of the above conditions present? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 4 .
4. (K855) 5 VOLT SUPPLY CIRCUIT OPEN OR SHORTED TO GROUND Disconnect the CKP Sensor connector. Ignition on, engine not running. Measure the voltage on the (K855) 5 Volt Supply circuit in the Sensor harness connector. Is the voltage between 4.5 and 5.2 Volts? Yes Go To 5 . No Repair the open or short to ground in the (K855) 5 Volt Supply circuit. Use Miller PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) when checking for an open circuit to prevent PCM harness connector terminal damage. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
5. TONE WHEEL/FLEX PLATE INSPECTION Turn the ignition off. Disconnect the Negative Battery (Ground) cable. Remove the Crankshaft Position Sensor. Inspect the Tone Wheel/Flex Plate slots for damage, foreign material or excessive movement. Were any issues found? Yes Repair or replace the Tone Wheel/Flex Plate as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 6 .
6. CHECKING CAMSHAFT POSITION SENSOR SIGNAL WITH A LAB SCOPE Install the CKP Sensor and connect the battery cable. NOTE: An intermittent condition in the Cam Position Sensor can cause the P0339 to set. With the a lab scope probe and the Miller special tool (special tool #6801, Terminal Probe), backprobe the (K44) CMP Signal circuit in the Sensor harness connector. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. Ignition on, engine not running. Wiggle the related wire harness and lightly tap on the Cam Position Sensor. Observe the lab scope screen. Start the engine. Observe the lab scope screen. NOTE: On multiple CMP sensor engines repeat this test for the other signal circuits Are there any irregular or missing signals? Yes Verify that there is good pin to terminal contact in the CMP Sensor and Powertrain Control Module connectors. Replace the Camshaft Position Sensor if no issues were found with the connectors. Refer to «SENSOR, CAMSHAFT POSITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/ignition-system/#ignition-system-service-information) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 7 .
7. CRANKSHAFT POSITION SENSOR Repair Verify that there is good pin to terminal contact in the CKP Sensor and Powertrain Control Module connectors. Replace the Crankshaft Position Sensor if no issues were found with the connectors. Refer to «SENSOR, CRANKSHAFT POSITION, REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/fuel-system/#fuel-system) . Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
8. (K24) CKP SIGNAL CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Disconnect the C2 PCM harness connector. Disconnect the CKP Sensor harness connector. Ignition on, engine not running. Measure the voltage on the (K24) CKP Signal circuit in the Sensor harness connector. Wiggle the related wire harness while taking this measurement. Is there any voltage present? Yes Repair the short to voltage in the (K24) CKP Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 9 .
9. (K24) CKP SIGNAL CIRCUIT OPEN Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis. Measure the resistance in the (K24) CKP Signal circuit from the CKP harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position). Wiggle the wire harness while taking this measurement. Is the resistance below 1.0 Ohm? Yes Go To 10 . No Repair the excessive resistance in the (K24) CKP Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .
10. (K24) CKP SIGNAL CIRCUIT SHORTED TO GROUND Measure the resistance between ground and the (K24) CKP Signal circuit in the CKP Sensor harness connector. Wiggle the related wire harness while monitoring the resistance value. Does the resistance ever go below 100 Ohms? Yes Repair the short to ground in the (K24) Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 11 .
11. (K24) CKP SIGNAL CIRCUIT SHORTED TO THE (K855) 5 VOLT SUPPLY CIRCUIT Measure the resistance between the (K855) 5 Volt Supply circuit and the (K24) CKP Signal circuit in the CKP harness connector. Wiggle the related wire harness while taking this measurement. Is the resistance below 5.0 Ohms? Yes Repair the short between the (K855) 5 Volt Supply circuit and the (K24) CKP Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Go To 12 .
12. POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the related Sensor and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Crankshaft Position Sensor and the Powertrain Control Module connectors. Perform any Technical Service Bulletins that may apply. Were there any issues found? Yes Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) . No Replace and program the Powertrain Control Module in accordance with the Service Information. Perform the POWERTRAIN VERIFICATION TEST. Refer to «POWERTRAIN VERIFICATION TEST»(/jeep/grand-cherokee/wk2-2010-2013/remont/testing-diagnostics/#36l-57l-intermittent-condition-pcmecm-reprogramming-gas-powertrain-verification-test-pre-diagnostic-troubleshooting-proc) .

See also:
• PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE
• SENSOR, OXYGEN, REMOVAL
• MODULE, POWERTRAIN CONTROL, REMOVAL
• SENSOR, COOLANT TEMPERATURE, REMOVAL
• SOLENOID, EVAPORATIVE EMISSIONS PURGE, REMOVAL
• SENSOR, OIL TEMPERATURE, REMOVAL
• CHECKING EXHAUST RESTRICTION
• COIL, IGNITION, REMOVAL
• FUEL PRESSURE LEAK DOWN
• CRANKSHAFT, REMOVAL, 5.7L