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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.
  1. 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.
    2. NOTE: If an engine knock can be heard, repair the engine mechanical condition before proceeding with this diagnostic.
  2. Observe and record the Freeze Frame/Failure Records data for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running DTC or as close to the Freeze Frame/Failure Records data that you observed. Does the DTC fail this ignition cycle? If yes, go to next step. If no, see INTERMITTENT CONDITIONS  under SELF-DIAGNOSTIC SYSTEM.
  3. Turn OFF the ignition and wait 30 seconds. Disconnect the PCM connector. Connect a DMM between the KS signal circuit and the KS low reference circuit. Set the DMM to the 400 mV AC hertz scale and wait for the DMM to stabilize at 0 Hz. Observe the DMM while tapping on the engine block with a non-metallic object. Does the DMM display a fluctuating frequency while tapping on the block? If yes, go to step  7. If no, go to next step.
  4. Test for an open in the knock sensor signal or low reference circuits. Did you find and correct the condition? If yes, go to step  12. If no, go to next step.
  5. Test the signal circuit for a short to the low reference circuit Did you find and correct the condition? If yes, go to step  12. If no, go to next step.
  6. Inspect for a poor connection at the knock sensor harness connector and at the knock sensor/starter solenoid harness connector. Did you find and correct the condition? If yes, go to step  12. If no, go to step  10.
    7. NOTE: Disconnection of the PCM during testing may eliminate the voltage or ground source that caused this fault.
  7. Test for a short to ground or a short to voltage in the KS signal circuit. Did you find and correct the condition? If yes, go to step  12. If no, go to next step.
    8. NOTE: Disconnecting the PCM during testing may eliminate the voltage or ground source that caused this fault.
  8. Test for a short to ground or short to voltage in the KS low reference circuit. Did you find and correct the condition? If yes, go to step  12. If no, go to next step.
  9. Inspect for a poor connection at the harness connector of the PCM. Did you find and correct the condition? If yes, go to step  12. If no, go to step  11.
  10. Replace the knock sensor. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. After repairs, go to step  12.
  11. Replace the PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Reprogram PCM. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After repairs, go to next step.
  12. 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.
  13. 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.
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