Dtcs P0123 to P0174: Other Jeep Commander I

Monitor Conditions

1. When Monitored: With the ignition on. Battery voltage greater than 10 volts.

Set Conditions

1. Set Condition: Throttle Position Sensor No. 1 voltage is greater than 4.8 volts for 25 ms. One Trip Fault. ETC light will illuminate.

Possible Causes

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

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1. 1) ACTIVE DTC NOTE: When this DTC is Active the engine speed, torque, and vehicle speed are limited to a Limp in mode. NOTE: Make sure the throttle is fully closed and free from binding or carbon build up. NOTE: If a 5-Volt Supply DTC has also set, diagnose the 5-Volt DTC before continuing. 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 P0123. Start the engine and allow it to reach operating temperature. With the scan tool select View DTCs. NOTE: If the DTC does not reset it may be necessary to test drive the vehicle. NOTE: If the P2123-APP Sensor 1 Circuit High DTC is also Active, diagnose the P2123 before continuing with the P0123 diagnostic procedure. Is the DTC Active at this time? Yes Go to 2) . No Go to 8) .
2. 2) THROTTLE POSITION SENSOR Turn the ignition off. Disconnect the Throttle Body harness connector. Connect a jumper wire between the (K22) TP Sensor No. 1 Signal circuit and the (K922) Sensor Return circuit in the Throttle Body harness connector. With a scan tool, monitor the TP Sensor No. 1 voltage. Ignition on, engine not running. Is the voltage below 0.5 of a volt with the jumper wire installed? Yes 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. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 3) . NOTE: Remove the jumper wire before continuing.
3. 3) (K22) TP SENSOR NO. 1 SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE Turn the ignition off. Disconnect the C2 PCM harness connector. Ignition on, engine not running. Measure the voltage on the (K22) TP Sensor No. 1 Signal circuit in the Throttle Body harness connector. Is the voltage above 0 volts? Yes Repair the short to battery voltage in the (K22) TP Sensor No. 1 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 4) .
4. 4) (K22) TP 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 Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K22) TP Sensor No. 1 Signal circuit from the Throttle Body harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 5) . No Repair the open in the (K22) TP Sensor No. 1 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
5. 5) (K22) TP SENSOR NO. 1 SIGNAL CIRCUIT SHORTED TO THE (F855) 5-VOLT SUPPLY CIRCUIT Measure the resistance between the (K22) TP Sensor No. 1 Signal circuit and the (F855) 5-volt Supply circuit in the Throttle Body harness connector. Is the resistance below 100 ohms? Yes Repair the short between the (F855) 5-volt Supply circuit and the (K22) TP Sensor No. 1 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 6) .
6. 6) (K922) SENSOR RETURN CIRCUIT OPEN Measure the resistance of the (K922) Sensor Return circuit from the Throttle Body harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 7) . No Repair the open in the (K922) Sensor Return circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
7. 7) PCM NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
8. 8) THROTTLE FOLLOWER TEST With a scan tool, perform the Throttle Follower Test. Monitor the TP Sensor No. 1 voltage. Does voltage start at approximately 0.3 of a volt and go above 4.7 volts with a smooth transition? Yes Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure. No 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. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

Scheme 83

1. When Monitored: With the ignition on. Battery voltage greater than 10.4 volts.

1. Set Condition: Throttle Position Sensor voltage at the PCM is greater than 4.47 volts for 1.3 seconds. 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 .

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1. 1) ACTIVE DTC NOTE: When this DTC is Active the engine speed, torque, and vehicle speed are limited to a Limp in mode. NOTE: Make sure the throttle is fully closed and free from binding or carbon build up. NOTE: If a 5-Volt Supply DTC has also set, diagnose the 5-Volt DTC before continuing. Start the engine and allow it to reach operating temperature. With the scan tool select View DTCs. NOTE: If the DTC does not reset it may be necessary to test drive the vehicle. Is the DTC Active at this time? Yes Go to 2) . No Go to 8) .
2. 2) THROTTLE POSITION SENSOR Turn the ignition off. Disconnect the TP Sensor harness connector. Connect a jumper wire between the (K22) TP Sensor No. 1 Signal circuit and the (K900) Sensor ground circuit in the Sensor harness connector. With a scan tool, monitor the TP Sensor voltage. Ignition on, engine not running. Is the voltage below 0.5 of a volt with the jumper wire installed? Yes Replace the Throttle Position Sensor. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 3) . NOTE: Remove the jumper wire before continuing.
3. 3) (K22) TP SENSOR NO. 1 SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE Turn the ignition off. Disconnect the C2 PCM harness connector. Ignition on, engine not running. Measure the voltage on the (K22) TP Sensor No. 1 Signal circuit in the TP Sensor harness connector. Is the voltage above 0 volts? Yes Repair the short to battery voltage in the (K22) TP Sensor No. 1 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 4) .
4. 4) (K22) TP 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 Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K22) TP Sensor No. 1 Signal circuit from the TP Sensor harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 5) . No Repair the open in the (K22) TP Sensor No. 1 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
5. 5) (K22) TP SENSOR NO. 1 SIGNAL CIRCUIT SHORTED TO THE (F855) 5-VOLT SUPPLY CIRCUIT Measure the resistance between the (K22) TP Sensor No. 1 Signal circuit and the (F855) 5-volt Supply circuit in the TP Sensor harness connector. Is the resistance below 100 ohms? Yes Repair the short between the (F855) 5-volt Supply circuit and the (K22) TP Sensor No. 1 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 6) .
6. 6) (K900) SENSOR GROUND CIRCUIT OPEN Measure the resistance of the (K900) Sensor ground circuit from the TP Sensor harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 7) . No Repair the open in the (K900) Sensor ground circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
7. 7) PCM NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
8. 8) THROTTLE POSITION SENSOR SWEEP With a scan tool, monitor the Throttle Position Sensor voltage. Slowly open the throttle from the idle position to the wide open throttle position. Does voltage start at approximately 0.8 of a volt and go above 3.5 volts with a smooth transition? Yes Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure. No Replace the Throttle Position Sensor. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

Scheme 89

1. When Monitored: With battery voltage greater than 10.4 volts and after engine is started.

1. Set Condition: The engine temperature does not go above -10° C (15° F). Failure time depends on start-up coolant temperature and ambient temperature. (i.e. 2 minutes for a start temp of -10° C (15° F) or up to 10 minutes for a vehicle with a start-up temp of -28° C (5° F). 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. When Monitored: Engine running.

1. Set Condition: This diagnostic will fail when the model temperature reaches 91° C (196° F) before the ECT. reaches 80° C (176° F). This monitor only runs after a cold start condition ECT, ACT, AMB are all within 10° C (50° F) of one another. 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 .

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1. 1) ACTIVE DTC NOTE: If any ECT, AAT, CMP or CKP sensor DTCs have set along with P0128, diagnose them before continuing. NOTE: Make sure that the Pinion Factor has been programmed correctly into the PCM. Start the engine. Allow the engine to reach normal operating temperature. With a 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 Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 2) LOW COOLANT LEVEL NOTE: If an Engine Coolant Temperature (ECT) DTC is set along with this code, diagnose the ECT DTC first. NOTE: Inspect the ECT terminals and related PCM terminals. Make sure the terminals are free from corrosion and damage. NOTE: The best way to diagnose this DTC is to allow the vehicle to sit overnight outside in order to have a totally cold soaked engine. NOTE: Extremely cold outside ambient temperatures may have caused this DTC to set. WARNING: Never open the cooling system when the engine is hot. The system is under pressure. Failure to follow these instructions can result in personal injury including extreme burns, scalding, or death. Allow the engine to cool before opening the cooling system. Check the coolant system to make sure that the coolant is in good condition and at the proper level. Is the coolant level and condition OK? Yes Go to 3) . No Inspect the vehicle for a coolant leak and add the necessary amount of coolant. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
3. 3) THERMOSTAT OPERATION NOTE: This test works best if performed on a cold engine (cold soak). Ignition on, engine not running. With a scan tool, read the ECT Deg 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 Deg value. The temp deg value change should be a smooth transition from start up to normal operating temp 82° C (180° F). Also monitor the actual coolant temperature with a thermometer. NOTE: As the engine warms up to operating temperature, the actual coolant temperature (thermometer reading) and the scan tool, ECT Temperature value should stay relatively close to each other. Using the appropriate service information, determine the proper opening temperature of the thermostat. Did the thermostat open at the proper temperature? Yes Go to 4) . No Replace the thermostat. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
4. 4) AMBIENT AIR TEMP SENSOR OPERATION Ignition on, engine not running. With a scan tool, read and record the AAT Sensor Temperature value. Using the DRB Temperature Probe #CH7050, or an equivalent temperature measuring tool, measure the ambient air temperature near the AAT Sensor. Is the AAT Sensor value with -15° C (5° F) of the temperature probe reading? Yes Go to 5) . No Go to 7) .
5. 5) ECT SENSOR OPERATION WARNING: Make sure the engine cooling system is cool before removing the pressure cap or any hose. The cooling system is pressurized when hot. Failure to follow these instructions can result in personal injury including extreme burns, scalding, or death. With a scan tool, read and record the ECT Sensor Temperature value. Use the DRB Temperature Probe #CH7050, or an equivalent temperature measuring tool, measure the engine coolant temperature. Is the ECT Sensor value with -15° C (5° F) of the temperature probe reading? Yes Go to 6) . No Go to 7) .
6. 6) OTHER POSSIBLE CAUSES Inspect the Temperature Sensors for any physical damage. Inspect the engine coolant. Make sure the coolant is at the proper level. Refer to the Service Information for COOLING. Make sure the Temperature Sensors are properly installed. Make sure the CMP and CKP sensors are installed properly. Check the connectors for any signs of damage. 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 can result in personal injury or death. Refer to any Technical Service Bulletins (TSBs) that may apply. With the engine running at normal operating temperature, monitor the Temperature sensor parameters while wiggling the wire harness. Look for parameter values to change. Visually inspect the related wire harness. Look for any chafed, pierced, pinched, partially broken wires and broken, bent, pushed out, or corroded terminals. 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 Miller Special Tool #8815 to perform diagnosis. Inspect and clean all PCM, engine, and chassis grounds. Were any problems found during the above inspections? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Test Complete, the conditions that set this DTC are not present at this time.
7. 7) SIGNAL CIRCUIT SHORTED TO VOLTAGE NOTE: Visually inspect both the component and the PCM connectors. Look for damage, partially broken wires and backed out or corroded terminals Turn the ignition off. Disconnect the applicable Temperature Sensor harness connector. Disconnect the C2 FCM harness connector and the C2 PCM harness connector. Ignition on, engine not running. Measure the voltage on the (K2) ECT Signal circuit and the (G31) AAT Signal circuit at the appropriate Temperature Sensor harness connector. Is there any voltage present? Yes Repair the short to voltage in the Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 8) .
8. 8) TEMPERATURE SENSOR Turn the ignition off. Connect the C2 FCM harness connector and the C2 PCM harness connector. Ignition on, engine not running. With a scan tool, read the Temperature Sensor voltage. Connect a jumper wire across the ECT and AAT Sensor harness connectors. Does the voltage start at 5.0 volts and drop below 1.0 volt when the jumper wire is installed? Yes Replace the appropriate Temperature Sensor. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 9) . NOTE: Disconnect the jumper wire before continuing.
9. 9) 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 Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K2) ECT Sensor Signal circuit from the ECT Sensor harness connector to the appropriate terminal of special tool #8815. Measure the resistance of the (G31) AAT Sensor Signal circuit from the AAT Sensor harness connector to the C2 FCM harness connector. Is the resistance below 5.0 ohms? Yes Go to 10) . No Repair the open in the Sensor Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
10. 10) SENSOR GROUND CIRCUIT OPEN Measure the resistance of the (K900) Sensor ground circuit from the appropriate Temperature Sensor harness connector to the appropriate terminal of special tool #8815. Measure the resistance of the (G931) Sensor ground circuit from the AAT Sensor harness connector to the C2 FCM harness connector. Is the resistance below 5.0 ohms? Yes Go to 11) . No Repair the open in the Sensor ground circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
11. 11) SIGNAL CIRCUIT SHORTED TO GROUND Measure the resistance between ground and the Sensor Signal circuit in the Temperature Sensor harness connector. Is the resistance below 100 ohms? Yes Repair the short to ground in the Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 12) .
12. 12) SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT OR THE (G931) SENSOR GROUND CIRCUIT Measure the resistance between the Signal circuit and the (K900) Sensor ground circuit in the (K2) ECT Sensor harness connector. Measure the resistance between the Signal circuit and the (G931) Sensor ground circuit in the (G31) AAT Sensor harness connector. Is the resistance below 100 ohms? Yes Repair the short between the Sensor ground circuit and the Sensor Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 13) .
13. 13) PCM NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

Scheme 102

1. When Monitored: With the ignition key on. No Cam or Crank signal within 75 ms. Engine speed less than 250 RPM.

1. Set Condition: The PCM senses the voltage from the MAP sensor to be less than 2.2 volts but above 0.04 of a volt for 300 milliseconds. One Trip Fault. Three good trips to turn off the MIL. MIL is illuminated and the ETC lamp will flash.

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

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1. 1) ACTIVE DTC Ignition on, engine not running. With a scan tool, select View DTCs. Is the DTC Active at this time. Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 2) (F856) 5-VOLT SUPPLY CIRCUIT Turn the ignition off. Disconnect the MAP Sensor harness connector. Ignition on, engine not running. Measure the voltage on the (F856) 5-volt Supply circuit in the MAP Sensor harness connector. Is the voltage between 4.5 to 5.2 volts? Yes Go to 3) . No Go to 7) .
3. 3) MAP SENSOR With a scan tool, monitor the MAP Sensor voltage with the Sensor harness connector disconnected. Is the voltage above 2.2 volts? Yes Verify that there is good pin to terminal contact in the MAP Sensor and Powertrain Control Module connectors. If OK, replace the MAP Sensor. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 4) .
4. 4) (K1) MAP 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 Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K1) MAP Signal circuit from the MAP Sensor harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 5) . No Repair the open in the (K1) MAP Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
5. 5) (K1) MAP SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT Measure the resistance between the (K900) Sensor ground circuit and the (K1) MAP Signal circuit in the MAP Sensor harness connector. Is the resistance below 5.0 ohms? Yes Repair the short between the (K900) Sensor ground circuit and the (K1) MAP Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 6) .
6. 6) (K1) MAP SIGNAL CIRCUIT SHORTED TO GROUND Measure the resistance between ground and the (K1) MAP Signal circuit in the MAP Sensor harness connector. Is the resistance below 100 ohms? Yes Repair the short to ground in the (K1) MAP Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 10) .
7. 7) (F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Disconnect the C1 PCM harness connector. Ignition on, engine not running. Measure the voltage on the (F856) 5-volt Supply circuit in the MAP Sensor harness connector. Is there any voltage present? Yes Repair the short to voltage in the (F856) 5-volt Supply circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 8) .
8. 8) (F856) 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 Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (F856) 5-volt Supply circuit from the MAP Sensor harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 9) . No Repair the open in the (F856) 5-volt Supply circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
9. 9) (F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND Measure the resistance between ground and the (F856) 5-volt Supply circuit in the MAP Sensor harness connector. Is the resistance below 100 ohms? Yes Repair the short to ground in the (F856) 5-volt Supply circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 10) .
10. 10) POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the MAP 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 MAP Sensor and Powertrain Control Module connectors. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

Scheme 109

1. 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 10.4 volts.

1. Set Condition: The PCM detects that the 1/1 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.

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

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1. 1) ACTIVE DTC Turn the ignition on. With a scan tool, select View 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 can result in personal injury or death. With a scan tool, select View DTCs. Is the DTC Active or Pending at this time? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 2) (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT Turn the ignition off. Disconnect the 1/1 O2 Sensor harness connector. Ignition on, engine not running. With a scan tool, monitor the O2 Sensor voltage. Is the 1/1 O2 Sensor voltage between 4.1 and 5.0 volts? Yes Go to 3) . No Go to 5) .
3. 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 1/1 Oxygen Sensor and Powertrain Control Module connectors. If OK, replace the 1/1 O2 Sensor. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 4) .
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 «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 8) .
5. 5) (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C1 and C2 PCM harness connectors. Measure the resistance between ground and the (K41) O2 Sensor 1/1 Signal circuit in the O2 Sensor harness connector. Is the resistance below 100 ohms? Yes Repair the short to ground in the (K41) O2 Sensor 1/1 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 6) .
6. 6) (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT SHORTED TO THE (K902) O2 RETURN UPSTREAM CIRCUIT Measure the resistance between the (K41) O2 Sensor 1/1 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 (K41) O2 Sensor 1/1 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 7) .
7. 7) (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT SHORTED TO THE (Z42) O2 1/1 HEATER GROUND CIRCUIT Measure the resistance between the (K41) O2 Sensor 1/1 Signal circuit and the (Z42) O2 1/1 Heater ground circuit in the O2 Sensor harness connector. Is the resistance below 100 ohms? Yes Repair the short between the (Z42) O2 1/1 Heater ground circuit and the (K41) O2 Sensor 1/1 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 8) .
8. 8) POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/1 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. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

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

1. Set Condition: The Oxygen Sensor voltage is above the maximum 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 .

Scheme 115

Scheme 116

Scheme 117

Scheme 118

Scheme 119

1. 1) ACTIVE 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 can result in personal injury or death. With a scan tool, select View DTCs. Is the status Active for this DTC? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 2) (K41) O2 1/1 SIGNAL CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Disconnect the C1 and C2 PCM harness connectors. Disconnect the 1/1 O2 Sensor harness connector. Turn the ignition on. Measure the voltage on the (K41) O2 Sensor 1/1 Signal circuit in the 1/1 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 (K41) O2 Sensor 1/1 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 3) .
3. 3) (K902) O2 RETURN UPSTREAM CIRCUIT SHORTED TO VOLTAGE Measure the voltage on the (K902) O2 Return Upstream circuit in the 1/1 O2 Sensor harness connector. Is there any voltage present? Yes Repair the short to voltage in the (K902) O2 Return Upstream circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 4) .
4. 4) 1/1 O2 SENSOR Turn the ignition off. Connect the C1 and C2 PCM harness connectors. Ignition on, engine not running. With a scan tool, monitor the 1/1 O2 Sensor voltage. Connect a jumper wire between the (K41) O2 1/1 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 installed? Yes Verify that there is good pin to terminal contact in the 1/1 Oxygen Sensor and Powertrain Control Module connectors. If OK, replace the 1/1 O2 Sensor. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 5) . NOTE: Remove the jumper wire before continuing.
5. 5) (K41) O2 1/1 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 Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K41) O2 1/1 Signal circuit from the 1/1 O2 Sensor harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 6) . No Repair the open in the (K41) O2 1/1 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
6. 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 special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 7) . No Repair the open in the (K902) O2 Return Upstream circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
7. 7) POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/1 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. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

1. When Monitored: 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 3 minutes.

1. Set Condition: The 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 .

1. When Monitored: Engine running and heater duty cycle greater than 0%. Battery voltage greater than 11.0 volts.

1. Set Condition: The PCM detects no temperature change in the O2 sensor heater element when the heater circuit is active. The heater temperature is obtained by measuring the heater resistance and calculating the heater temperature. 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 120

Scheme 121

1. 1) O2 SENSOR HEATER OPERATION Turn the ignition off. NOTE: Wait a minimum of 8 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 a scan tool, actuate the 1/1 O2 Heater Test. With the scan tool, monitor 1/1 O2 Sensor voltage for at least 2 minutes. Does the voltage stay above 4.5 volts? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 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 O2 Heater Element across the 1/1 O2 Sensor connector between the O2 Heater Control terminal and the 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 Sensor and Control Module connectors. If OK, replace the O2 Sensor. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
3. 3) (K99) O2 1/1 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 Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K99) O2 1/1 Heater Control circuit from the O2 harness connector to the appropriate terminal of special tool #8815. Is the resistance below 0.5 of an ohm? Yes Go to 4) . No Repair the excessive resistance in the (K99) O2 1/1 Heater Control circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
4. 4) (Z42) O2 1/1 HEATER GROUND CIRCUIT OPEN Measure the resistance between ground and the (Z42) O2 1/1 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 (Z42) O2 1/1 Heater ground circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
5. 5) POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/1 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 Sensor and Control Module connectors. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

Scheme 122

1. 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.

1. Set Condition: The PCM detects that the 1/2 Oxygen Sensor signal voltage is below 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 .

Scheme 123

Scheme 124

Scheme 125

Scheme 126

Scheme 127

1. 1) ACTIVE DTC Turn the ignition on. With a scan tool, select View 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 can result in personal injury or death. With a scan tool, select View DTCs. Is the DTC Active at this time? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 2) (K141) O2 1/2 SIGNAL CIRCUIT Turn the ignition off. Disconnect the 1/2 O2 Sensor harness connector. Ignition on, engine not running. With a scan tool, monitor the 1/2 O2 Sensor voltage. Is the O2 Sensor voltage between 4.1 and 5.0 volts? Yes Go to 3) . No Go to 5) .
3. 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 1/2 O2 Sensor and Powertrain Control Module connectors. If OK, replace the 1/2 O2 Sensor. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 4) .
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 «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 8) .
5. 5) (K141) O2 1/2 SIGNAL CIRCUIT SHORTED TO GROUND Turn the ignition off. Disconnect the C1 and C2 PCM harness connectors. Measure the resistance between ground and the (K141) O2 1/2 Signal circuit in the O2 Sensor harness connector. Is the resistance below 100 ohms? Yes Repair the short to ground in the (K141) O2 1/2 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 6) .
6. 6) (K141) O2 1/2 SIGNAL CIRCUIT SHORTED TO THE (K904) O2 RETURN DOWNSTREAM CIRCUIT Measure the resistance between the (K141) O2 1/2 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 (K141) O2 1/2 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 7) .
7. 7) (K141) O2 1/2 SIGNAL CIRCUIT SHORTED TO THE (Z42) O2 1/2 HEATER GROUND CIRCUIT Measure the resistance between the (K141) O2 1/2 Signal circuit and the (Z42) O2 1/2 Heater ground circuit in the O2 Sensor harness connector. Is the resistance below 100 ohms? Yes Repair the short between the (Z42) O2 1/2 Heater ground circuit and the (K141) O2 1/2 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 8) .
8. 8) POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/2 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 O2 Sensor and Powertrain Control Module connectors. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

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

1. Set Condition: The PCM detects that the 1/2 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 128

1. 1) ACTIVE 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 can result in personal injury or death. With a scan tool, select View DTCs. Is the DTC Active at this time? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 2) (K141) O2 1/2 SIGNAL CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Disconnect the C1 and C2 PCM harness connectors. Disconnect the 1/2 O2 Sensor harness connector. Turn the ignition on. Measure the voltage on the (K141) O2 Sensor 1/2 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 (K141) O2 Sensor 1/2 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 3) .
3. 3) (K904) O2 RETURN DOWNSTREAM CIRCUIT SHORTED TO VOLTAGE Measure the voltage on the (K904) O2 Return Downstream circuit in the O2 Sensor harness connector. Is there any voltage present? Yes Repair the short to voltage in the (K904) O2 Return Downstream circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 4) .
4. 4) O2 SENSOR Turn the ignition off. Connect the C1 and C2 PCM harness connectors. Ignition on, engine not running. With a scan tool, monitor the 1/2 O2 Sensor voltage. Connect a jumper wire between the (K141) O2 1/2 Signal circuit and the (K904) O2 Return Downstream circuit in the 1/2 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 1/2 O2 Sensor and Powertrain Control Module connectors. If OK, replace the 1/2 O2 Sensor. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 5) . NOTE: Remove the jumper wire before continuing.
5. 5) (K141) O2 1/2 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 Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K141) O2 1/2 Signal circuit from the O2 Sensor harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 6) . No Repair the open in the (K141) O2 1/2 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
6. 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 special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 7) . No Repair the open in the (K904) O2 Return Downstream circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
7. 7) POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/2 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 O2 Sensor and Powertrain Control Module connectors. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

1. When Monitored: 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.

1. Set Condition: The PCM detects that the oxygen sensor signal switches from lean to rich less than 16 times 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. When Monitored: 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.

1. Set Condition: The 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. When Monitored: 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.

1. Set Condition: The 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 .

Scheme 129

Scheme 130

1. 1) ACTIVE 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 can result in personal injury or death. With a 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 Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 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 #8404-EC or #8404-EC 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 #8404-ECT with equipped attached plug, plug one side of the dual exhaust pipe. Pressurize the other as described above. Apply SNOOP leak finder liquid or a mixture of liquid dish soap and water 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 «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 3) .
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 per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
4. 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 per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
5. 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. Refer to any Technical Service Bulletins that may apply. Were any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace the 2/2 Oxygen Sensor in accordance with the Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

1. When Monitored: Continuously during O2 sensor heater operation with battery voltage between 10.4 and 15.75 volts and no O2 sensor circuit DTCs present.

1. Set Condition: The PCM detects no temperature change in the O2 sensor heater element when the heater circuit is active. The heater temperature is obtained by measuring the heater resistance and calculating the heater temperature. 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 131

1. 1) O2 SENSOR HEATER OPERATION Turn the ignition off. NOTE: Wait a minimum of 8 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 a scan tool, actuate the 1/2 O2 Heater Test. With the scan tool, monitor 1/2 O2 Sensor voltage for at least 2 minutes. Does the voltage stay above 4.5 volts? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 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 O2 Heater Element across the O2 Sensor connector between the O2 Heater Control terminal and the 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 1/2 O2 Sensor and Powertrain Control Module connectors. If OK, replace the 1/2 O2 Sensor. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
3. 3) (K299) O2 1/2 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 Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K299) O2 1/2 Heater Control circuit from the O2 harness connector to the appropriate terminal of special tool #8815. Is the resistance below 0.5 of an ohm? Yes Go to 4) . No Repair the excessive resistance in the (K299) O2 1/2 Heater Control circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
4. 4) (Z42) O2 1/2 HEATER GROUND CIRCUIT OPEN Measure the resistance between ground and the (Z42) O2 1/2 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 (Z42) O2 1/2 Heater ground circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
5. 5) POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/2 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 O2 Sensor and Powertrain Control Module connectors. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

Scheme 132

1. 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.

1. Set Condition: The 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.

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

Scheme 133

Scheme 134

Scheme 135

Scheme 136

Scheme 137

1. 1) ACTIVE DTC Turn the ignition on. With a scan tool, select View 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 can result in personal injury or death. With a scan tool, select View DTCs. Is the DTC Active at this time? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 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 a 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. 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. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 4) .
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 «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 8) .
5. 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 «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 6) .
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 «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 7) .
7. 7) (K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO THE (Z42) HEATER GROUND CIRCUIT Measure the resistance between the (K43) O2 2/1 Signal circuit and the (Z42) O2 Heater ground circuit in the O2 Sensor harness connector. Is the resistance below 100 ohms? Yes Repair the short between the (Z42) O2 Heater ground circuit and the (K43) O2 2/1 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 8) .
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. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

1. When Monitored: 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.

1. Set Condition: The 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 138

1. 1) ACTIVE 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 can result in personal injury or death. With a scan tool, select View DTCs. Is the DTC Active at this time? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 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 «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 3) .
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 «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 4) .
4. 4) O2 SENSOR Turn the ignition off. Connect the C1 and C2 PCM harness connectors. Ignition on, engine not running. With a 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. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 5) . NOTE: Remove the jumper wire before continuing.
5. 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 Miller Special Tool #8815 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 special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 6) . No Repair the open in the (K43) O2 2/1 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
6. 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 special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 7) . No Repair the open in the (K902) O2 Return Upstream circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
7. 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. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

1. When Monitored: 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 3 minutes.

1. Set Condition: The 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 .

1. When Monitored: Engine running and heater duty cycle greater than 0%. Battery voltage greater than 11.0 volts.

1. Set Condition: 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 139

1. 1) O2 SENSOR HEATER OPERATION Turn the ignition off. NOTE: Wait a minimum of 8 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 a scan tool, actuate the O2 Heater Test. With the scan tool, monitor 2/1 O2 Sensor voltage for at least 2 minutes. Does the voltage stay above 4.5 volts? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 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. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
3. 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 Miller Special Tool #8815 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 special tool #8815. 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 «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
4. 4) (Z42) O2 SENSOR HEATER GROUND CIRCUIT OPEN Measure the resistance between ground and the (Z42) 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 (Z42) O2 Heater ground circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
5. 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. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

1. 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.

1. Set Condition: The 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. When Monitored: 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.

1. Set Condition: The 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 140

1. 1) ACTIVE 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 can result in personal injury or death. With a scan tool, select View DTCs. Is the DTC Active at this time? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 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 «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 3) .
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 «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 4) .
4. 4) O2 SENSOR Turn the ignition off. Connect the C1 and C2 PCM harness connectors. Ignition on, engine not running. With a 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. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 5) . NOTE: Remove the jumper wire before continuing.
5. 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 Miller Special Tool #8815 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 special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 6) . No Repair the open in the (K243) O2 2/2 Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
6. 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 special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 7) . No Repair the open in the (K904) O2 Return Downstream circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
7. 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. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

1. When Monitored: 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.

1. Set Condition: 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. When Monitored: Engine running and heater duty cycle greater than 0%. Battery voltage greater than 11.0 volts.

1. Set Condition: 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 141

1. 1) O2 SENSOR HEATER OPERATION Turn the ignition off. NOTE: Wait a minimum of 8 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 a scan tool, actuate the O2 Heater Test. With a scan tool, monitor 2/2 O2 Sensor voltage for at least 2 minutes. Does the voltage stay above 4.5 volts? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 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. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
3. 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 Miller Special Tool #8815 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 special tool #8815. 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 «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
4. 4) (Z42) O2 2/2 HEATER GROUND CIRCUIT OPEN Measure the resistance between ground and the (Z42) 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 (Z42) O2 2/2 Heater ground circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
5. 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. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

Scheme 142

1. When Monitored: 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).

1. Set Condition: If the 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. When Monitored: 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).

1. Set Condition: If the 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. When Monitored: 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).

1. Set Condition: If the 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 .