FixVault
Home › Buick › 2003 › Century Base › Repair and Diagnosis › Engine Performance › System › Engine Controls Self-Diagnostics - 3.1L Engine › Diagnostic Tests › DTC P0327: Knock Sensor Circuit › Diagnostic Procedure

Diagnostic Procedure

  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. Start the engine. Monitor the Diagnostic Trouble Code (DTC) information using the scan tool. Does the scan tool display any other DTCs set? If yes, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, go to next step.
  3. Monitor the 24X Crank Sensor parameter using the scan tool. Is the 24X Crank Sensor parameter incrementing? If yes, go to next step. If no, go to DTC P0336: CRANKSHAFT POSITION SENSOR PERFORMANCE .
    4. NOTE: If an engine mechanical noise can be heard, repair the condition before proceeding with this test. See appropriate article in ENGINES.
  4. Observe the Freeze Frame/Failure Records data for this DTC. Turn ignition switch to OFF position for 30 seconds. Start the engine. Operate the vehicle within the Conditions For Running Test. See CONDITIONS FOR RUNNING TEST . You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Does the DTC fail this ignition? If yes, go to next step. If no, go to DIAGNOSTIC AIDS .
  5. Disconnect the KS harness connector. Set the DMM to the 400 k/ohm scale. Measure the resistance from the KS signal terminal to a good ground using the DMM. Is the resistance 93-107 k/ohms? If yes, go to next step. If no, go to step  10.
  6. With the DMM still connected, set the DMM to the 400 mV AC hertz scale. Tap on the engine block with a nonmetallic object near the KS while observing the signal indicated on the DMM. DO NOT tap on plastic engine components. Is any signal indicated on the DMM while tapping on the engine block near the KS? If yes, go to next step. If no, go to step  10.
  7. Turn ignition switch to OFF position. Disconnect the PCM harness connectors. Check the KS signal circuit and the KS low reference circuit for an open, high resistance, short to voltage or short to ground. Did you find and correct the condition? If yes, go to step  12. If no, go to next step.
  8. Test for an intermittent and for a poor connection at the KS. Did you find and correct the condition? If yes, go to step  12. If no, go to next step.
  9. Check for an intermittent and for a poor connection at the PCM. Did you find and correct the condition? If yes, go to step  12. If no, go to step  11.
  10. Replace KS. After repair, go to step  12.
  11. Replace PCM. See POWERTRAIN CONTROL MODULE in appropriate REMOVAL & INSTALLATION article. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After replacing PCM, go to next step.
  12. Using scan tool, clear the DTCs. Turn the ignition OFF for 30 seconds. Start the engine. Operate the vehicle within the Conditions For Running Test. See CONDITIONS FOR RUNNING TEST . You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Does the DTC fail this ignition? If yes, go to step  2. If no, go to next step.
  13. Using the scan tool, observe the stored information in CAPTURE INFO. Does the scan tool display any DTCs that you have not diagnosed? If yes, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay at this time.
About FixVault