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.

Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM.
Are DTCs P0102, P0410, P0412 and P0443 set? If yes, go to next step. If no, go to step 4.

NOTE: Replace the fuse after completing the repair.

Locate and repair the following circuit conditions:
- Any short to ground in the ignition feed circuit.
- Any shorted component that shares the ignition feed fuse. See POWER DISTRIBUTION article in WIRING DIAGRAMS.
After repairs, go to step 16.

NOTE: If the vehicle is equipped with the dual secondary AIR injection system, then throughout the diagnostic procedure, the relay designation will be the AIR pump relay 1 instead of AIR pump relay.

Install a scan tool. Turn ON the ignition, with the engine OFF. Command the AIR pump relay ON and OFF with a scan tool. Does the AIR pump relay turn ON and OFF with each command? If yes, go to next step. If no, go to step 6.
Review the Freeze Frame/Failure Records data for this DTC. Turn the ignition OFF for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running DTC, or as close as possible to the Freeze Frame/Failure Records data that you observed. Does the DTC reset? If yes, go to next step. If no, see DIAGNOSTIC AIDS .
Turn the ignition OFF. Remove the AIR pump relay. Turn the ignition ON, with the engine OFF. Probe the AIR pump relay ignition supply circuit with the Test Lamp (J 34142-B) connected to ground. Does the test lamp illuminate? If yes, go to next step. If no, go to step 13.
Connect a test lamp between the control circuit of the AIR pump relay and the ignition supply circuit of the AIR pump relay. Command the AIR pump relay ON and OFF with a scan tool. Does the test lamp turn ON and OFF with each command? If yes, go to step 11. If no, go to next step.
Does the test lamp remain illuminated with each command? If yes, go to step 10. If no, go to next step.
Test the control circuit of the AIR pump relay for the following conditions:
- A short to voltage.
- An open.
If you find a condition, repair the condition as necessary. Did you find and correct the condition? If yes, go to step 16. If no, go to step 12.
Test the control circuit of the AIR pump relay for a short to ground. If you find a condition, repair the condition as necessary. Did you find and correct the condition? If yes, go to step 16. If no, go to step 15.
Inspect for poor connections at the AIR pump relay. If you find a condition, repair the condition as necessary. Did you find and correct the condition? If yes, go to step 16. If no, go to step 14.
Inspect for poor connections at the PCM. If you find a condition, repair the condition as necessary. Did you find and correct the condition? If yes, go to step 16. If no, go to step 15.
Repair the ignition supply circuit for the AIR pump relay. After repairs, go to step 16.
Replace the AIR pump relay. After repairs, go to step 16.
Replace the PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Reprogram PCM. See POWERTRAIN CONTROL MODULE under PROGRAMMING. After repairs, go to next step.
Use the scan tool in order to clear the DTCs. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running DTC. Does the DTC run and pass? If yes, go to next step. If no, go to step 2.
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.