Diagnostic Procedures
WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
- Perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check - engine controls, go to next step.
- Turn ignition on, with engine off. Command the affected HO2S heater ON with a scan tool. Wait 15 seconds to allow the HO2S heater current to stabilize. Observe the affected HO2S heater current parameter with a scan tool. Is the HO2S heater current parameter within 0.22-1.56 amps? If yes, go to next step. If no, go to step 4.
- Observe the Freeze Frame/Failure Records for this DTC. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running the DTC. See CONDITIONS FOR RUNNING 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? If yes, go to next step. If no, problem is intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L & 3.0L VUE article.
- Inspect the EMISS fuse. Is the EMISS fuse open? If yes, go to next step. If no, go to step 6.
- Test ignition 1 voltage circuit for a short to ground. Did you find and correct the condition? If yes, go to step 20. If no, go to step 8.
- Disconnect the affected HO2S. Turn ignition on, with engine off. Probe the ignition 1 voltage circuit of the HO2S harness connector on the engine harness side with a test light that is connected to a good ground. Test light should illuminate. If yes, go to next step. If no, go to step 17.
- Connect a test light between the ignition 1 voltage circuit of the HO2S harness connector on the engine harness side and the HO2S heater low control circuit of the HO2S harness connector on the engine harness side. Command the affected HO2S heater ON and OFF with a scan tool. Does the test light turn ON and OFF with each command? If yes, go to step 9. If no, go to step 10.
- Test ignition 1 voltage circuit on the sensor side of the HO2S connector for a short to ground. Is any sensor shorted to ground? If yes, go to step 18. If no, problem is intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L & 3.0L VUE article.
- Measure the resistance of the HO2S heater low control circuit and the ignition 1 voltage circuit. Is the resistance of either circuit greater than 3 ohms? If yes, go to step 16. If no, go to step 14.
- Does the test light remain illuminated with each command? If yes, go to next step. If no, go to step 12.
- Test HO2S heater low control circuit for a short to ground. Did you find and correct the condition? If yes, go to step 20. If no, go to step 15.
- Test HO2S heater low control circuit for a short to voltage. Did you find and correct the condition? If yes, go to step 20. If no, go to next step.
- Test HO2S heater low control circuit for an open. Did you find and correct the condition? If yes, go to step 20. If no, go to step 15.
- Test for an intermittent and for a poor connection at the HO2S. Did you find and correct the condition? If yes, go to step 20. If no, go to step 18.
- Test for an intermittent and for a poor connection at the ECM. Did you find and correct the condition? If yes, go to step 20. If no, go to step 19.
- Repair circuit with high resistance. After repairs, go to step 20.
- Repair open in the ignition 1 voltage circuit. After repairs, go to step 20.
- Replace affected HO2S. After replacing sensor, go to step 20.
- Turn ignition off. Replace ECM. Perform ECM relearn procedure. See ELECTRONIC CONTROL MODULE REPROGRAMMING under PROGRAMMING. After replacing ECM, go to next step.
- Were you sent to this diagnostic from DTC P0134? If yes, go to step 18 in DTC P0134. If no, go to next step.
- Were you sent to this diagnostic from DTC P0140? If yes, go to step 18 in DTC P0140. If no, go to next step.
- Replace the EMISS fuse if necessary. Clear the DTCs with a scan tool. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running the DTC. See CONDITIONS FOR RUNNING 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? If yes, go to step 2. If no, go to next step.
- With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
NOTE:
Perform the following test on all HO2S' which are supplied voltage by the suspect circuit.