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Home >> Saturn >> 2003 >> LW200 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0327: Knock Sensor Circuit >> Diagnostic Procedures
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Diagnostic Procedures

  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 mechanical noise can be heard, repair the condition before proceeding with this diagnostic.
  2. Observe the Freeze Frame/Failure Records data for this DTC. Turn ignition off for 30 seconds. Start the 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. Does the DTC fail this ignition? If yes, go to next step. If no, problem is intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L SATURN "L" SERIES article.
  3. Turn ignition off. Disconnect the KS harness connector. Measure the resistance from the KS signal circuit on the sensor side of the KS harness connector to a good ground with the DVOM. Measure the resistance from the KS low reference circuit on the sensor side of the KS harness connector to a good ground with the DVOM. Does the DVOM display an open for both circuits? If yes, go to next step. If no, go to step  8.
  4. Connect the DVOM from the KS signal circuit to the KS low reference circuit on the sensor side of the KS harness connector. Set the DVOM to the 400 mV AC hertz scale and wait for the DVOM to stabilize at 0 Hz. DO NOT tap on plastic engine components. Tap on the engine block with a non-metallic object near the KS while observing the signal indicated on the DVOM. Does the DVOM display a fluctuating frequency while tapping on the engine block? If yes, go to next step. If no, go to step  8.
  5. Turn ignition on, with engine off. On the PCM side of the KS harness connector, measure the DC voltage from the KS signal circuit to a good ground with a DVOM. On the PCM side of the KS harness connector, measure the DC voltage from the KS low reference circuit to a good ground with a DVOM. Is the voltage more than 4.5 volts on any circuit? If yes, go to next step. If no, go to step  7.
  6. Turn ignition off. Disconnect the PCM. Test the KS signal circuit or the KS low reference circuit for a short to voltage. Did you find and correct the condition? If yes, go to step  12. If no, go to step  9.
  7. Turn ignition off. Disconnect the PCM. Test the KS signal circuit and the KS low reference circuit for an open, short to ground, high resistance or short between both circuits. Did you find and correct the condition? If yes, go to step  12. If no, go to step  9.
  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 step  10.
  9. Test 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 replacement, go to step  12.
  11. Replace PCM. See POWERTRAIN CONTROL MODULE in REMOVAL & INSTALLATION - SATURN "L" SERIES article. Perform PCM relearn procedure. See PCM REPROGRAMMING  under PROGRAMMING. After replacing PCM, go to next step.
  12. Clear the DTCs with a scan tool. Turn ignition off for 30 seconds. Start the 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. Does the DTC fail this ignition? If yes, go to step  2. If no, go to next step.
  13. Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? If yes, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
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