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Home >> Buick >> 2002 >> Century Custom >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics - 3.1L Engine >> Diagnostic Tests >> DTC P0341: CMP Sensor Circuit Performance >> Diagnostic Procedures
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Diagnostic Procedures

  1. 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.
  2. Attempt to start engine. Does engine start and run? If yes, go to next step. If no, go to step  4.
  3. Turn ignition off for 30 seconds. Start engine. Operate vehicle within the Conditions for Running the DTC. See CONDITIONS FOR RUNNING DTC . You may 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 next step. If no, go to INTERMITTENT CONDITIONS  under SELF-DIAGNOSTIC SYSTEM.
  4. Turn ignition off. Disconnect CMP sensor connector. Turn ignition on, with engine off. Probe the 12-volt reference circuit of the CMP sensor harness connector with a test light that is connected to a good ground. Does the test light illuminate? If yes, go to step  6. If no, go to next step.
  5. Probe the 12-volt reference circuit of the CMP sensor harness connector with a test light that is connected to battery voltage. Does the test light illuminate? If yes, go to step  12. If no, go to step  11.
  6. Probe the low reference circuit of the CMP sensor harness connector with a test light that is connected to battery voltage. Does the test light illuminate? If yes, go to next step. If no, go to step  13.
  7. Jumper the 12-volt reference circuit from the CMP sensor to the CMP sensor harness connector. Jumper the low reference circuit from the CMP sensor to the CMP sensor harness connector. Measure the frequency from the CMP sensor signal circuit of the CMP sensor to a good ground with a DMM set to the DC voltage scale. Crank the engine. Does the frequency measure within 1-3 Hz? If yes, go to next step. If no, go to step  16.
  8. Disconnect PCM. Measure the resistance of the CMP sensor signal circuit from the CMP sensor harness connector to the PCM harness connector with a DMM. Does the resistance measure more than 5 ohms? If yes, go to step  18. If no, go to next step.
  9. Connect the PCM connector. Probe the signal circuit of the CMP sensor harness connector with a test light connected to battery voltage. Does the test light illuminate? If yes, go to step  14. If no, go to next step.
  10. Probe the signal circuit of the CMP sensor harness connector with a test light connected to a good ground. Does the test light illuminate? If yes, go to step  15. If no, go to step  17.
  11. Test the CMP 12-volt reference circuit between the CMP sensor and the PCM for an open or high resistance. Did you find and correct the condition? If yes, go to step  21. If no, go to step  17.
    NOTE: Disconnecting the PCM may remove the short from the circuit.
  12. Test the CMP 12-volt reference circuit between the CMP sensor and the PCM for a short to ground. Did you find and correct the condition? If yes, go to step  21. If no, go to step  20.
  13. Test the CMP low reference circuit between the CMP sensor and the PCM for an open or high resistance. Did you find and correct the condition? If yes, go to step  21. If no, go to step  17.
    NOTE: Disconnecting the PCM may remove the short from the circuit.
  14. Test the CMP signal circuit between the CMP sensor and the PCM for a short to ground. Did you find and correct the condition? If yes, go to step  21. If no, go to step  20.
    NOTE: Disconnecting the PCM may remove the short from the circuit.
  15. Test the CMP signal circuit between the CMP sensor and the PCM for a short to voltage. Did you find and correct the condition? If yes, go to step  21. If no, go to step  20.
  16. Test for an intermittent and for poor connections at the CMP harness connector. If you find a poor connection, repair the connector as necessary. Did you find and correct the condition? If yes, go to step  21. If no, go to step  19.
  17. Test for an intermittent and for poor connections at the PCM harness connector. If you find a poor connection, repair the connector as necessary. Did you find and correct the condition? If yes, go to step  21. If no, go to step  20.
  18. Repair the CMP signal circuit between the CMP sensor and the PCM for an open or high resistance. After repairs, go to step  21.
  19. Replace CMP sensor. After repairs, go to step  21.
  20. Replace PCM. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After replacing PCM, go to next step.
  21. Clear the DTCs with a scan tool. Turn ignition off for 30 seconds. Start engine. Operate the 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.
  22. Using scan tool, observe stored information and Capture Info. If scan tool displays any undiagnosed DTCs, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no other DTCs are displayed, system is okay.
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