Diagnostic Procedures
WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. 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.
- Inspect the IGN 1 fuse. Is fuse open? If yes, go to step 10. If no, go to next step.
- Turn ignition off. Disconnect PCM. Turn ignition on, with engine off. Connect a 3-amp fuse jumper wire between the MIL control circuit and a good ground. Observe MIL. Is MIL illuminated? If yes, go to step 9. If no, go to next step.
- Did fuse in jumper wire open? If yes, go to step 11. If no, go to next step.
- Remove the Instrument Panel Cluster (IPC). Test the MIL control circuit for an open between the PCM and IPC. Did you find and correct the condition? If yes, go to step 14. If no, go to next step.
- Probe MIL battery voltage circuit at IPC harness connector with a test lamp connected to a good ground. Does test lamp illuminate? If yes, go to step 8. If no, go to next step.
- Repair open in MIL battery voltage circuit. After repairs, go to step 14.
- Inspect for poor connections at the IPC harness connector. Did you find and correct the condition? If yes, go to step 14. If no, go to step 12.
- Inspect for poor connections at PCM harness connector. Did you find and correct the condition? If yes, go to step 14. If no, go to step 13.
- Repair short to ground in MIL battery voltage circuit. Replace fuse. After repairs, go to step 14.
- Repair short to voltage in MIL control circuit. After repairs, go to step 14.
- Replace IPC. See appropriate ANALOG INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. After repairs, go to step 14.
- Replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE under PROGRAMMING. When complete, go to next step.
- Operate system in order to verify repair. Did you correct the condition? If yes, system is okay. If no, go to step 2.