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.
- Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS .
- Observe the DTC information with a scan tool. Is DTC P0101, P0121, P0122, P0123, P0221, P0222, P0223, P2122, P2123, P2127, or P2128 also set? If yes, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, go to next step.
- Turn ignition off. Disconnect the APP sensor electrical connector. Disconnect the ECM. Measure the resistance of the following circuits with a DVOM for each of the APP sensors: The low reference circuit, signal circuit and 5-volt reference circuit. Is resistance more than 5 ohms for any circuit? If yes, go to step 7. If no, go to next step.
- Test the signal circuit of APP sensor 1 for a short to the signal circuit of APP sensor 2. Did you find and correct the condition? If yes, go to step 9. If no, go to next step.
- Test for an intermittent and for a poor connection at the APP sensor. Did you find and correct the condition? If yes, go to step 9. If no, go to next step.
- Test for an intermittent and for a poor connection at the ECM. Did you find and correct the condition? If yes, go to step 9. If no, go to step 8.
- Repair high resistance in the circuit that measured more than the specified value. After repairs, go to step 9.
- Replace APP sensor. After replacing sensor, go to next step.
- Clear the DTCs with a scan tool. Turn ignition off for 30 seconds. Start engine. Operate 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.
- Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? If yes, diagnose affected DTC(s). See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are displayed, system is okay.