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Home >> Jeep >> 2020 >> Compass Trailhawk >> Repair and Diagnosis >> Engine Performance >> System >> 2.4L - DTCS P0141 To P0600 >> DTC Troubleshooting >> P0325-Knock Sensor 1 Circuit >> Diagnostic Test

Diagnostic Test

  1. CHECK FOR AN ACTIVE DTC 
    1. Start the engine.
    2. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
    3. With the scan tool, read DTCs and record on the repair order.

      Is the DTC active or pending?

      Yes 

      • Go to 2

      No 

  2. CHECK THE (K42) KNOCK SENSOR 1 SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE 
    1. Turn the ignition off.
    2. Disconnect the Knock Sensor harness connector and inspect the terminals for poor connections.
    3. Turn the ignition on.
    4. Measure the voltage on the (K42) Knock Sensor 1 Signal circuit in the Knock Sensor harness connector.

      Is the voltage above 5.2 volts?

      Yes 

      • Repair the (K42) Knock Sensor 1 Signal circuit for a short to voltage or poor connection.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go to 3
  3. CHECK THE (K42) KNOCK SENSOR 1 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Turn the ignition off.
    2. Disconnect the PCM C2 harness connector.
      CAUTION:

      Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.

    3. Connect the (special tool #10436, Adapter, GPEC Diagnostic)to the engine harness side of the PCM C2 harness connector. Do not connect the GPEC Diagnostic Adaptor to the PCM.
    4. Measure the resistance of the (K42) Knock Sensor 1 Signal circuit from the Knock Sensor harness connector to the GPEC Adaptor.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go to 4

      No 

      • Repair the (K42) Knock Sensor 1 Signal circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  4. CHECK THE (K942) KNOCK SENSOR 1 RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Measure the resistance of the (K942) Knock Sensor 1 Return circuit from the Knock Sensor harness connector to the GPEC Adaptor.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go to 5

      No 

      • Repair the (K942) Knock Sensor 1 Return circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  5. CHECK FOR THE (K42) KNOCK SENSOR 1 SIGNAL CIRCUIT SHORTED TO THE (K942) KNOCK SENSOR 1 RETURN CIRCUIT 
    1. Check for continuity between the (K42) Knock Sensor 1 Signal circuit and the (K942) Knock Sensor 1 Return circuit in the Knock Sensor harness connector.

      Is there continuity between the (K42) Knock Sensor Signal circuit and the (K942) Knock Sensor Return circuit?

      Yes 

      • Repair the short between the (K42) Knock Sensor 1 Signal circuit and the (K942) Knock Sensor 1 Return circuit.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go to 6
  6. CHECK THE (K42) KNOCK SENSOR 1 SIGNAL CIRCUIT FOR A SHORT TO GROUND 
    1. Check for continuity between ground and the (K42) Knock Sensor 1 Signal circuit in the Knock Sensor harness connector.

      Is there continuity between ground and the (K42) Knock Sensor Signal circuit?

      Yes 

      • Repair the (K42) Knock Sensor 1 Signal circuit for a short to ground.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go to 7
  7. REPLACE THE KNOCK SENSOR AND RETEST FOR DTCS 
    1. Replace the Knock Sensor in accordance with the Service Information.
    2. Connect the Knock Sensor and PCM C2 harness connectors.
    3. Turn the ignition on.
    4. With the scan tool, erase DTCs.
    5. Using the recorded Freeze Frame Data and the When Monitored conditions above, operate the vehicle within the conditions that set the DTC.
    6. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      • Go to 8

      No 

  8. CHECK RELATED HARNESS CONNECTIONS 
    1. Disconnect all PCM harness connectors.
    2. Disconnect all related in-line harness connections (if equipped).
    3. Disconnect the related component harness connectors.
    4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
      • Proper connector installation.
      • Damaged connector locks.
      • Corrosion.
      • Other signs of water intrusion.
      • Weather seal damage (if equipped).
      • Bent terminals.
      • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
      • Terminals that have been pushed back into the connector cavity.
      • Check for spread terminals and verify proper terminal tension.

      Repair any conditions that are found.

    5. Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
    6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
    7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
    8. With the scan tool, erase DTCs.
    9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
    10. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      No 

      • The wiring or poor connection problem has been repaired.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .