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.
Is DTC P0340 also set? If yes, go to next step. If no, go to step 7.
Test the CMP 12-volt reference circuit for the following conditions:
- An intermittent open
- Poor connections at the PCM and at the CMP sensor
If a condition is found, repair the condition as necessary. Did you find and correct the condition? If yes, go to step 8. If no, go to next step.
Test the CMP high resolution signal circuit for the following conditions:
- An intermittent open.
- An intermittent short to ground or to the CMP sensor low reference.
- An intermittent short to the CMP 12-volt reference circuit.
- Poor connections at the PCM and at the CMP sensor.
If a condition is found, repair the condition as necessary. Did you find and correct the condition? If yes, go to step 8. If no, go to next step.
Test the CMP sensor low reference circuit for the following conditions:
- An intermittent open.
- Poor connections at the PCM and at the CMP sensor.
If a condition is found, repair the condition as necessary. Did you find and correct the condition? If yes, go to step 8. If no, go to next step.
Test the CMP harness wiring for improper routing near high frequency devices. If a condition is found, correct the condition as necessary. Did you find and correct the condition? If yes, go to step 8. If no, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.
Test the valve train for the following conditions:
- Damaged or misaligned camshaft timing components.
- Proper camshaft timing. See appropriate article in ENGINES.
If a condition is found, repair the condition as necessary. Did you find and correct the condition? If yes, go to next step. If no, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.
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.