Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 5: This test will determine the ability of the PCM and IAC valve control circuits to control the IAC valve.
- 7: This test will determine the ability of the PCM to provide the IAC valve control circuits with a ground. On a normally operating system, the test lamp should not flash while the IAC Counts are incrementing.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | IMPORTANT: Ensure that the Engine Speed parameter stabilizes with each Commanded RPM change to determine if engine speed stays within 200 RPM of the Commanded RPM. Set the parking brake and block the drive wheels. Start the engine. Turn OFF all accessories. Slowly increment the engine speed to 1,700 RPM, then to 600 RPM, then to 1,700 RPM with the scan tool RPM Control function. Exit the RPM control function. Did the Engine Speed parameter stabilize within 200 RPM of the Commanded RPM? | Go to Step 3 | Go to Step 4 |
| 3 | Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? | Go to Step 4 | Go to Diagnostic Aids |
| 4 | Turn OFF the ignition. Disconnect the idle air control (IAC) valve. Connect a J 37027-1A IAC Motor Driver to the IAC valve. See Special Tools . Start the engine. Command the IAC valve in until 600 RPM is reached with the J 37027-1A . See Special Tools . Command the IAC valve out until 1,700 RPM is reached with the J 37027-1A . See Special Tools . Return the engine speed to the Desired Idle Speed parameter. Did the Engine Speed parameter steadily decrease to 600 RPM and steadily increase to 1,700 RPM when the IAC valve was commanded in and out? | Go to Step 5 | Go to Step 11 |
| 5 | Connect the test lamp between one of the IAC valve control circuits and a good ground. Start the engine. Observe the IAC Counts parameter with a scan tool and observe the test lamp. Command high RPM with the J 37027-1A until the IAC Counts parameter starts to increment. See Special Tools . Command low RPM with the J 37027-1A until the IAC Counts parameter starts to increment. See Special Tools . Return the Engine Speed parameter to the Desired Idle Speed parameter. Repeat the above procedure for the other 3 IAC valve control circuits. Did the test lamp remain ON, never flashing, while the IAC Counts were incrementing for any of the IAC valve control circuits? | Go to Step 10 | Go to Step 6 |
| 6 | Did the test lamp remain OFF, never flashing, while the IAC Counts were incrementing for any of the IAC valve control circuits? | Go to Step 9 | Go to Step 7 |
| 7 | Connect a test lamp between the IAC coil A low control circuit and the IAC coil A high control circuit. Observe the IAC Counts parameter with a scan tool and observe the test lamp. Command high RPM with the J 37027-1A until the IAC Counts parameter starts to the increment. See Special Tools . Command low RPM with the J 37027-1A until the IAC Counts parameter starts to increment. See Special Tools . Return the Engine Speed parameter to the Desired Idle Speed parameter as indicated on the scan tool data list. Repeat the above procedure with the test lamp connected between the IAC coil B low control circuit and the IAC coil B high control circuit. Did the test lamp stay illuminated and never flashing while the IAC Counts were incrementing for any of the IAC valve control circuits? | Go to Step 8 | Go to Step 16 |
| 8 | Test for an intermittent and for a poor connection at the IAC valve. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 17 | Go to Step 12 |
| 9 | Turn OFF the ignition. Disconnect the powertrain control module (PCM). Test the IAC valve control circuit where the test lamp remained OFF for the following conditions: An open circuit A short to ground A short to another IAC valve control circuit-Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 17 | Go to Step 12 |
| 10 | Turn ON the ignition. Test the IAC valve control circuit where the test lamp remained ON for the following conditions: A short to voltage A short to another IAC valve control circuit-Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 17 | Go to Step 12 |
| 11 | Inspect for the following conditions: Throttle body damage and tampering Throttle lever screw tampering, if equipped Vacuum leaks Faulty, incorrectly installed positive crankcase ventilation (PCV) valve and hose, if equipped Throttle shaft binding Throttle linkage or cruise control linkage binding, if equipped Remove the IAC valve. Refer to Idle Air Control (IAC) Valve Replacement . Inspect for the following conditions: Debris in the IAC passage Excessive deposits on the throttle plate Excessive deposits in the throttle bore Excessive deposits on IAC valve pintle Did you find and correct the condition? | Go to Step 17 | Go to Step 14 |
| 12 | Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 17 | Go to Step 13 |
| 13 | Disconnect the PCM. Test all IAC valve control circuits for high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 17 | Go to Step 16 |
| 14 | Test for an intermittent and for a poor connection at the IAC valve. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 17 | Go to Step 15 |
| 15 | Replace the IAC valve. Refer to Idle Air Control (IAC) Valve Replacement . Did you complete the replacement? | Go to Step 17 | |
| 16 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 17 | |
| 17 | Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? | Go to Step 2 | Go to Step 18 |
| 18 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK |
| IMPORTANT |
|---|
| Ensure that the Engine Speed parameter stabilizes with each Commanded RPM change to determine if engine speed stays within 200 RPM of the Commanded RPM. |
DTC P0507
Description
This diagnostic applies to internal microprocessor integrity conditions within the powertrain control module (PCM). This diagnostic also addresses whether or not the PCM is not programmed.
The number below refers to the step number on the diagnostic table.
- 2: A DTC P0602 indicates the PCM is not programmed.
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Is DTC P0602 set? | Go to Step 3 | Go to Step 5 |
| 3 | Program the powertrain control module (PCM). Refer to Powertrain Control Module Programming and Setup . Does DTC P0602 reset? | Go to Step 4 | Go to Step 7 |
| 4 | Ensure that all tool connections are secure. Ensure that the programming equipment is operating correctly. Ensure that the correct software/calibration package is used. Attempt to program the PCM. Refer to Powertrain Control Module Programming and Setup . Does DTC P0602 reset? | Go to Step 6 | Go to Step 7 |
| 5 | Test all voltage and grounds inputs to the PCM for an open circuit or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 7 | Go to Step 6 |
| 6 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 7 | |
| 7 | Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Did the DTC fail this ignition? | Go to Step 2 | Go to Step 8 |
| 8 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK |
DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681, P1683, or P2610
The numbers below refer to the step numbers on the diagnostic table.
- 5: This step tests for a short to ground in the MIL control circuit. With the powertrain control module (PCM) disconnected and the ignition ON, the MIL should be OFF.
- 6: This step tests for a short to voltage on the MIL control circuit. With the fuse removed, there should be no voltage on the MIL control circuit.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Instrument Cluster Schematics or Engine Controls Schematics Connector End View Reference: Instrument Panel, Gages, and Console Connector End Views or Powertrain Control Module (PCM) Connector End Views | ||||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle | |
| 2 | Command the malfunction indicator lamp (MIL) ON and OFF with a scan tool. Does the MIL turn ON and OFF when commanded with a scan tool? | Go to Step 3 | Go to Step 4 | |
| 3 | Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Does the DTC fail this ignition? | Go to Step 4 | Go to Testing for Intermittent Conditions and Poor Connections | |
| 4 | Is the MIL always ON? | Go to Step 5 | Go to Step 6 | |
| 5 | Turn OFF the ignition. Disconnect the powertrain control module (PCM). Refer to Powertrain Control Module (PCM) Replacement . Turn ON the ignition. Is the MIL OFF? | Go to Step 11 | Go to Step 13 | |
| 6 | Turn OFF the ignition. Disconnect the PCM. Remove the fuse that supplies voltage to the MIL. Turn ON the ignition, with the engine OFF. Measure the voltage from the MIL control circuit in the PCM harness connector to a good ground. Is the voltage less than the specified value? | 1 V | Go to Step 7 | Go to Step 14 |
| 7 | Turn OFF the ignition. Install the fuse that supplies voltage to the MIL. Turn ON the ignition, with the engine OFF. Connect a 3-amp fused jumper wire between the MIL control circuit of the PCM harness connector and a good ground. Is the MIL illuminated? | Go to Step 11 | Go to Step 8 | |
| 8 | Turn OFF the ignition. Remove the instrument panel cluster (IPC). Turn ON the ignition, with the engine OFF. Probe all ignition and battery positive voltage circuits of the IPC harness connector with a test lamp that is connected to a good ground. Does the test lamp illuminate for all circuits? | Go to Step 9 | Go to Step 12 | |
| 9 | Test the MIL control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct a condition? | Go to Step 17 | Go to Step 10 | |
| 10 | Test for an intermittent and for a poor connection at the IPC. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 17 | Go to Step 15 | |
| 11 | Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 17 | Go to Step 16 | |
| 12 | Repair the open in the ignition or battery positive voltage circuits. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 17 | ||
| 13 | Repair the a short to ground in the MIL control circuit. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 17 | ||
| 14 | Repair the short to voltage in the MIL control circuit. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 17 | ||
| 15 | Replace the IPC. Refer to Instrument Panel Cluster (IPC) Replacement . Did you complete the replacement? | Go to Step 17 | ||
| 16 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 17 | ||
| 17 | Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? | Go to Step 2 | Go to Step 18 | |
| 18 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK | |
DTC P0650
The number below refers to the step number on the diagnostic table.
- 7: This test will determine an intermittent faulty TP sensor utilizing the MIN MAX, 100-millisecond capture mode on the DMM.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Disconnect the throttle position (TP) sensor electrical connector. Turn ON the ignition, with the engine OFF. Measure the voltage from the 5-volt reference circuit of the TP sensor to a good ground with a DMM. Lightly touch and move the related engine wiring harnesses and connectors for all 5-volt reference circuits while observing voltage. Any change in voltage indicates the area where a short to voltage may be found. Refer to Testing for Electrical Intermittents and Wiring Repairs . Did you find and correct the condition? | Go to Step 9 | Go to Step 3 |
| 3 | Measure the voltage from the signal circuit of the TP sensor to a good ground with a DMM. Lightly touch and move the related engine wiring harnesses and connectors while observing voltage. Any change in voltage indicates the area where a short to voltage may be found. Refer to Testing for Electrical Intermittents and Wiring Repairs . Did you find and correct the condition? | Go to Step 9 | Go to Step 4 |
| 4 | Measure the resistance from the low reference circuit of the TP sensor to a good ground with a DMM. Lightly touch and move the related engine wiring harnesses and connectors while observing resistance. Any change in resistance indicates the area where an open or high resistance may be found. Refer to the following: Testing for Electrical Intermittents Testing for Intermittent Conditions and Poor Connections Wiring Repairs Did you find and correct the condition? | Go to Step 9 | Go to Step 5 |
| 5 | Test for intermittent and for poor connections at the TP sensor harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 9 | Go to Step 6 |
| 6 | Test for intermittent and for poor connections at the powertrain control module (PCM) harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
| 7 | Turn OFF the ignition. Measure the resistance between the TP sensor signal terminal and the low reference terminal at the TP sensor using the MIN MAX function on the DMM. Slowly press the accelerator pedal to the wide open throttle (WOT) position, then release the pedal back to the closed throttle position several times. Did you observe a MAX value of infinite ohms or a MIN value of 0 ohms. | Go to Step 8 | Go to Testing for Intermittent Conditions and Poor Connections |
| 8 | Replace the TP sensor. Refer to Throttle Position (TP) Sensor Replacement . Did you complete the replacement? | Go to Step 9 | |
| 9 | Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? | Go to Step 2 | Go to Step 10 |
| 10 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK |
DTC P1121
The number below refers to the step number on the diagnostic table.
- 6: This test will determine an intermittent faulty TP sensor utilizing the MIN MAX, 100-millisecond capture mode on the DMM.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Disconnect the throttle position (TP) sensor. Measure the voltage from the 5-volt reference circuit of the TP sensor to a good ground, with a DMM. Turn ON the ignition, with the engine OFF. Lightly touch and move the related engine wiring harnesses and connectors for all 5-volt reference circuits while observing the DMM. Any change in voltage indicates the area where an open or a short to ground in the 5-volt reference circuit may be found. Refer to the following procedures: Testing for Electrical Intermittents Testing for Intermittent Conditions and Poor Connections Wiring Repairs Did you find and correct the condition? | Go to Step 8 | Go to Step 3 |
| 3 | Connect the TP sensor. Install a scan tool and observe the TP sensor voltage parameter. Lightly touch and move the related engine wiring harnesses and connectors for the TP sensor signal circuit while observing the voltage. Any change in voltage indicates the area where an open or a short to ground in the TP sensor signal circuit may be found. Refer to Testing for Electrical Intermittents and Wiring Repairs . Did you find and correct the condition? | Go to Step 8 | Go to Step 4 |
| 4 | Test for intermittent and for poor connections at the TP sensor harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 8 | Go to Step 5 |
| 5 | Test for intermittent and for poor connections at the harness connector of the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 8 | Go to Step 6 |
| 6 | Turn OFF the ignition. Measure the resistance between the TP sensor signal terminal and the 5-volt reference terminal at the TP sensor using the MIN MAX function on the DMM. Slowly press the accelerator pedal to the wide open throttle (WOT) position, then release the pedal back to the closed throttle position several times. Did you observe a MAX value of infinite ohms or a MIN value of 0 ohms? | Go to Step 7 | Go to Testing for Intermittent Conditions and Poor Connections |
| 7 | Replace the TP sensor. Refer to Throttle Position (TP) Sensor Replacement . Did you complete the replacement? | Go to Step 8 | |
| 8 | Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? | Go to Step 2 | Go to Step 9 |
| 9 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK |
DTC P1122
The number below refers to the step number on the diagnostic table.
- 2: If the voltage is varying above and below the specified value, the condition is not present.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views | ||||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle | |
| 2 | Start the engine. Allow the engine to reach operating temperature. Refer to Scan Tool Data List . Operate the engine at 1,500 RPM for 30 seconds. Observe the affected Heated Oxygen Sensor (HO2S) Voltage parameter with a scan tool. Is the HO2S Voltage parameter varying above and below the specified range? | 250-625 mV | Go to Step 3 | Go to Step 4 |
| 3 | Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? | Go to Step 4 | Go to Testing for Intermittent Conditions and Poor Connections | |
| 4 | Turn OFF the ignition. Disconnect the affected HO2S. Turn ON the ignition, with the engine OFF. Observe the HO2S Voltage parameter with a scan tool. Is the HO2S Voltage parameter less than the specified value? | 100 mV | Go to Step 6 | Go to Step 5 |
| 5 | Connect a 3-amp fused jumper wire between the high signal circuit of the HO2S harness connector on the engine harness side and a good ground. Observe the HO2S Voltage parameter with a scan tool. Is the HO2S Voltage parameter less than the specified value? | 100 mV | Go to Step 8 | Go to Step 7 |
| 6 | Test the HO2S high signal circuit for a short to the HO2S low signal circuit. Refer to the following: Circuit Testing Heated Oxygen Sensor (HO2S) Wiring Repairs Wiring Repairs Did you find and correct the condition? | Go to Step 14 | Go to Step 11 | |
| 7 | Test the HO2S high signal circuit for an open or high resistance. Refer to the following: Circuit Testing Heated Oxygen Sensor (HO2S) Wiring Repairs Wiring Repairs Did you find and correct the condition? | Go to Step 14 | Go to Step 11 | |
| 8 | Remove the jumper wire from the previous step. Connect a 3-amp fused jumper wire between the high signal circuit of the HO2S harness connector on the engine harness side and the low signal circuit of the HO2S harness connector on the engine harness side. Observe the HO2S Voltage parameter with a scan tool. Is the HO2S Voltage parameter less than the specified value? | 100 mV | Go to Step 10 | Go to Step 9 |
| 9 | Test the HO2S low signal circuit for an open or high resistance. Refer to the following: Circuit Testing Heated Oxygen Sensor (HO2S) Wiring Repairs Wiring Repairs Did you find and correct the condition? | Go to Step 14 | Go to Step 11 | |
| 10 | Test for shorted terminals and for poor connections at the HO2S. Refer to the following: Testing for Intermittent Conditions and Poor Connections Heated Oxygen Sensor (HO2S) Wiring Repairs Connector Repairs Did you find and correct the condition? | Go to Step 14 | Go to Step 12 | |
| 11 | Test for shorted terminals and for poor connections at the powertrain control module (PCM). Refer to the following: Testing for Intermittent Conditions and Poor Connections Heated Oxygen Sensor (HO2S) Wiring Repairs Connector Repairs Did you find and correct the condition? | Go to Step 14 | Go to Step 13 | |
| 12 | NOTE: Refer to Silicon Contamination of Heated Oxygen Sensors Notice . IMPORTANT: The HO2S may be damaged due to contamination. Prior to replacing the HO2S, inspect for the following sources of contamination: A silicon contaminated HO2S Fuel contamination-Refer to Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool) or Alcohol/Contaminants-in-Fuel Diagnosis (With Special Tool) . Engine oil consumption-Refer to Oil Consumption Diagnosis . Engine coolant consumption-Refer to Loss of Coolant . Replace the affected HO2S. Refer to Heated Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 1 or Heated Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1 .Did you complete the replacement? | Go to Step 14 | ||
| 13 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 14 | ||
| 14 | Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? | Go to Step 2 | Go to Step 15 | |
| 15 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK | |
| NOTE |
|---|
| Refer to Silicon Contamination of Heated Oxygen Sensors Notice . |
| IMPORTANT |
|---|
| The HO2S may be damaged due to contamination. Prior to replacing the HO2S, inspect for the following sources of contamination |
DTC P1133 or P1153
The number below refers to the step number on the diagnostic table.
- 2: If the voltage is varying above and below the specified value, the condition is not present.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views | ||||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle | |
| 2 | Start the engine. Allow the engine to reach operating temperature. Refer to Scan Tool Data List . Operate the engine at 1,500 RPM for 30 seconds. Observe the affected Heated Oxygen Sensor (HO2S) Voltage parameter with a scan tool. Is the HO2S Voltage parameter varying above and below the specified range? | 250-625 mV | Go to Step 3 | Go to Step 4 |
| 3 | Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? | Go to Step 4 | Go to Testing for Intermittent Conditions and Poor Connections | |
| 4 | Turn OFF the ignition. Disconnect the affected HO2S. Connect a 3-amp fused jumper wire between the high signal circuit of the HO2S harness connector on the engine harness side and a good ground. Turn ON the ignition, with the engine OFF. Observe the HO2S Voltage parameter with a scan tool. Is the HO2S Voltage parameter less than the specified value? | 100 mV | Go to Step 6 | Go to Step 5 |
| 5 | Test the HO2S high signal circuit for an open or high resistance. Refer to the following: Circuit Testing Heated Oxygen Sensor (HO2S) Wiring Repairs Wiring Repairs Did you find and correct the condition? | Go to Step 12 | Go to Step 9 | |
| 6 | Remove the jumper wire from the previous step. Connect a 3-amp fused jumper wire between the high signal circuit of the HO2S harness connector on the engine harness side and the low signal circuit of the HO2S harness connector on the engine harness side. Observe the HO2S Voltage parameter with a scan tool. Is the HO2S Voltage parameter less than the specified value? | 100 mV | Go to Step 8 | Go to Step 7 |
| 7 | Test the HO2S low signal circuit for an open or high resistance. Refer to the following: Circuit Testing Heated Oxygen Sensor (HO2S) Wiring Repairs Wiring Repairs Did you find and correct the condition? | Go to Step 12 | Go to Step 9 | |
| 8 | Test for shorted terminals and for poor connections at the HO2S. Refer to the following: Testing for Intermittent Conditions and Poor Connections Heated Oxygen Sensor (HO2S) Wiring Repairs Connector Repairs Did you find and correct the condition? | Go to Step 12 | Go to Step 10 | |
| 9 | Test for shorted terminals and for poor connections at the powertrain control module (PCM). Refer to the following: Testing for Intermittent Conditions and Poor Connections Heated Oxygen Sensor (HO2S) Wiring Repairs Connector Repairs Did you find and correct the condition? | Go to Step 12 | Go to Step 11 | |
| 10 | NOTE: Refer to Silicon Contamination of Heated Oxygen Sensors Notice . IMPORTANT: The HO2S may be damaged due to contamination. Prior to replacing the HO2S, inspect for the following sources of contamination: A silicon contaminated HO2S Fuel contamination-Refer to Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool) or Alcohol/Contaminants-in-Fuel Diagnosis (With Special Tool) . Engine oil consumption-Refer to Oil Consumption Diagnosis . Engine coolant consumption-Refer to Loss of Coolant . Replace the affected HO2S. Refer to Heated Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 1 or Heated Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1 .Did you complete the replacement? | Go to Step 12 | ||
| 11 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 12 | ||
| 12 | Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? | Go to Step 2 | Go to Step 13 | |
| 13 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK | |
| NOTE |
|---|
| Refer to Silicon Contamination of Heated Oxygen Sensors Notice . |
| IMPORTANT |
|---|
| The HO2S may be damaged due to contamination. Prior to replacing the HO2S, inspect for the following sources of contamination |
DTC P1134 or P1154
System Description
The powertrain control module (PCM) detects engine misfire events by monitoring variations in the crankshaft rotation speed. Wheel speed changes caused by rough road conditions can cause changes in crankshaft rotation speed. By monitoring the wheel speed sensors, the antilock brake system (ABS) can determine if the vehicle is operating on a rough road. If the ABS is detecting a rough road condition severe enough to effect misfire detection, a rough road signal is sent to the PCM on the serial data circuit. If DTC P0300 is set with the malfunction indicator lamp (MIL) illuminated and the rough road information is not available due to an ABS malfunction, DTC P1380 will set.
The powertrain control module (PCM) detects engine misfire events by monitoring variations in the crankshaft rotation speed. Wheel speed changes caused by rough road conditions can cause changes in crankshaft rotation speed. By monitoring the wheel speed sensors, the antilock brake system (ABS) can determine if the vehicle is operating on a rough road. If the ABS is detecting a rough road condition severe enough to effect misfire detection, a rough road signal is sent to the PCM on the serial data circuit. If DTC P0300 is set with the malfunction indicator lamp (MIL) illuminated and the rough road information is not available due to an ABS malfunction, DTC P1381 will set.
The number below refers to the step number on the diagnostic table.
- 2: If the voltage does not change more that the specified value, the condition is present.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views | ||||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle | |
| 2 | Start the engine. Allow the engine to reach operating temperature. Refer to Scan Tool Data List . Operate the engine at 1,500 RPM for 30 seconds. While observing the affected Heated Oxygen Sensor (HO2S) Voltage parameter with a scan tool, quickly cycle the throttle from closed throttle to wide open throttle, 3 times. Did the HO2S Voltage parameter change more than the specified value? | 200 mV | Go to Step 3 | Go to Step 4 |
| 3 | Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? | Go to Step 4 | Go to Testing for Intermittent Conditions and Poor Connections | |
| 4 | Turn OFF the ignition. Disconnect the affected HO2S. Turn ON the ignition, with the engine OFF. Observe the HO2S Voltage parameter with a scan tool. Is the HO2S Voltage parameter less than the specified value? | 100 mV | Go to Step 6 | Go to Step 5 |
| 5 | Observe the HO2S Voltage parameter with a scan tool. Is the HO2S Voltage parameter more than the specified value? | 800 mV | Go to Step 7 | Go to Step 8 |
| 6 | Test the HO2S high signal circuit for a short to ground. Refer to the following: Circuit Testing Heated Oxygen Sensor (HO2S) Wiring Repairs Wiring Repairs Did you find and correct the condition? | Go to Step 20 | Go to Step 9 | |
| 7 | IMPORTANT: The sensor may be damaged if the circuit is shorted to a voltage source. Test the HO2S high signal circuit for a short to voltage. Refer to the folllowing: Circuit Testing Heated Oxygen Sensor (HO2S) Wiring Repairs Wiring Repairs Did you find and correct the condition? | Go to Step 20 | Go to Step 17 | |
| 8 | Measure the voltage from the low signal circuit of the HO2S harness connector on the engine harness side to a good ground with a DMM. Refer to Circuit Testing . Is the voltage more than the specified value? | 2 V | Go to Step 10 | Go to Step 11 |
| 9 | Test the HO2S high signal circuit for a short to the HO2S low signal circuit. Refer to the following: Circuit Testing Heated Oxygen Sensor (HO2S) Wiring Repairs Wiring Repairs Did you find and correct the condition? | Go to Step 20 | Go to Step 17 | |
| 10 | Test the HO2S low signal circuit for a short to voltage. Refer to the following: Circuit Testing Heated Oxygen Sensor (HO2S) Wiring Repairs Wiring Repairs Did you find and correct the condition? | Go to Step 20 | Go to Step 17 | |
| 11 | Connect a 3-amp fused jumper wire between the high signal circuit of the HO2S harness connector on the engine harness side and a good ground. Observe the HO2S Voltage parameter with a scan tool. Is the HO2S Voltage parameter less than the specified value? | 100 mV | Go to Step 12 | Go to Step 14 |
| 12 | Remove the jumper wire from the previous step. Connect a 3-amp fused jumper wire between the high signal circuit of the HO2S harness connector on the engine harness side and the low signal circuit of the HO2S harness connector on the engine harness side. Observe the HO2S Voltage parameter with a scan tool. Is the HO2S Voltage parameter less than the specified value? | 100 mV | Go to Step 15 | Go to Step 13 |
| 13 | Test the HO2S low signal circuit for an open or high resistance. Refer to the following: Circuit Testing Heated Oxygen Sensor (HO2S) Wiring Repairs Wiring Repairs Did you find and correct the condition? | Go to Step 20 | Go to Step 17 | |
| 14 | Test the HO2S high signal circuit for an open or high resistance. Refer to the following: Circuit Testing Heated Oxygen Sensor (HO2S) Wiring Repairs Wiring Repairs Did you find and correct the condition? | Go to Step 20 | Go to Step 17 | |
| 15 | The HO2S may be detecting a rich exhaust condition, a lean exhaust condition, or the HO2S may be contaminated. Inspect for the following conditions: NOTE: Refer to Silicon Contamination of Heated Oxygen Sensors Notice . A silicon contaminated HO2S Any water intrusion into the HO2S connector An exhaust leak between the HO2S and the engine Any vacuum leaks Engine oil contaminated with fuel An incorrect fuel pressure-Refer to Fuel System Diagnosis . Any lean or rich fuel injectors-Refer to Fuel Injector Balance Test with Tech 2 . An inaccurate mass air flow (MAF) sensor-Refer to Scan Tool Data List . Repair any of the above or similar engine conditions as necessary. Did you find and correct the condition? | Go to Step 20 | Go to Step 16 | |
| 16 | Test for shorted terminals and for poor connections at the HO2S. Refer to the following: Testing for Intermittent Conditions and Poor Connections Heated Oxygen Sensor (HO2S) Wiring Repairs Connector Repairs Did you find and correct the condition? | Go to Step 20 | Go to Step 18 | |
| 17 | Test for shorted terminals and for poor connections at the powertrain control module (PCM). Refer to the following: Testing for Intermittent Conditions and Poor Connections Heated Oxygen Sensor (HO2S) Wiring Repairs Connector Repairs Did you find and correct the condition? | Go to Step 20 | Go to Step 19 | |
| 18 | Replace the affected HO2S. Refer to Heated Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 2 or Heated Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 2 . Did you complete the replacement? | Go to Step 20 | ||
| 19 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 20 | ||
| 20 | Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? | Go to Step 2 | Go to Step 21 | |
| 21 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK | |
| IMPORTANT |
|---|
| The sensor may be damaged if the circuit is shorted to a voltage source. |
| NOTE |
|---|
| Refer to Silicon Contamination of Heated Oxygen Sensors Notice . |
DTC P2A01 or P2A04
See also:
• Scan Tool Data List