LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Acura >> 2012 >> RL >> Repair and Diagnosis >> Engine Performance >> System >> PGM-FI System >> DTC Troubleshooting >> DTC P0325: Knock Sensor Circuit Malfunction
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P0325: Knock Sensor Circuit Malfunction

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
  1. Turn the ignition switch to ON (II).
  2. Clear the DTC with the HDS.
  3. Start the engine. Hold the engine speed at 3, 000 RPM without load (in P or N) until the radiator fan comes on, then let it idle.
  4. Hold the engine speed at 3, 000-4, 000 RPM for at least 10 seconds.
  5. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P0325 indicated? 

    YES  -Go to step 6.

    NO  -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the knock sensor and the PCM.

  6. Turn the ignition switch to LOCK (0).
  7. Jump the SCS line with the HDS.
  8. Disconnect the knock sensor subharness 1P connector.
  9. Disconnect PCM connector C (49P).
  10. Check for continuity between PCM connector terminal C47 and body ground.
    Fig 1: Checking Continuity Between PCM Connector Terminal C47 And Body Ground
    G07361918Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short in the wire between the PCM (C47) and the knock sensor subharness, then go to step  20.

    NO  -Go to step 11.

  11. Connect engine wire harness (knock sensor) 1P connector terminal to body ground with a jumper wire.
    Fig 2: Connecting Engine Wire Harness (Knock Sensor) 1P Connector Terminal To Body Ground With Jumper Wire
    G07361919Courtesy of AMERICAN HONDA MOTOR CO., INC.
  12. Check for continuity between PCM connector terminal C47 and body ground.
    Fig 3: Checking Continuity Between PCM Connector Terminal C47 And Body Ground
    G07361920Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 13.

    NO  -Repair an open in the wire between the PCM (C47) and the engine wire harness (knock sensor) connector, then go to step  20.

  13. Remove the jumper wire from the engine wire harness.
  14. Remove the intake manifold (see INTAKE MANIFOLD REMOVAL AND INSTALLATION ) and the injector base (see INJECTOR BASE REMOVAL AND INSTALLATION ).
  15. Disconnect the knock sensor 1P connector.
  16. Check for continuity between the knock sensor 1P connector terminal and body ground.
    Fig 4: Checking Continuity Between Knock Sensor 1P Connector Terminal And Body Ground
    G07361921Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short in the knock sensor subharness, then go to step  19.

    NO  -Go to step 17.

  17. Check for an open in the knock sensor subharness.

    Is the harness OK? 

    YES  -Go to step 18.

    NO  -Repair an open in the knock sensor subharness, then go to step  19.

  18. Replace the knock sensor (see PCM UPDATE  ).
  19. Install the injector base (see INJECTOR BASE REMOVAL AND INSTALLATION ) and the intake manifold (see INTAKE MANIFOLD REMOVAL AND INSTALLATION ).
  20. Reconnect all connectors.
  21. Turn the ignition switch to ON (II).
  22. Reset the PCM with the HDS.
  23. Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
  24. Hold the engine speed at 3, 000-4, 000 RPM for at least 10 seconds.
  25. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P0325 indicated? 

    YES  -Check for poor connections or loose terminals at the knock sensor and the PCM, then go to step  27.

    NO  -Go to step 26.

  26. Monitor the OBD STATUS for DTC P0325 in the DTCs MENU with the HDS.

    Does the HDS indicate PASSED? 

    YES  -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step  25, go to the indicated DTC'S TROUBLESHOOTING .

    NO  -If the HDS indicates FAILED, check for poor connections or loose terminals at the knock sensor and the PCM, then go to step  1. If the HDS indicates NOT COMPLETED, go to step  24.

  27. Update the PCM if it does not have the latest software (see PCM UPDATE  ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ).
  28. Start the engine. Hold the engine speed at 3, 000 RPM without load (in P or N) until the radiator fan comes on, then let it idle.
  29. Hold the engine speed at 3, 000-4, 000 RPM for at least 10 seconds.
  30. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P0325 indicated? 

    YES  -Check for poor connections or loose terminals at the knock sensor and the PCM. If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE PCM ), then go to step  28. If the PCM was substituted, go to step  1.

    NO  -Go to step 31.

  31. Monitor the OBD STATUS for DTC P0325 in the DTCs MENU with the HDS.

    Does the HDS indicate PASSED? 

    YES  -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see PCM REPLACEMENT  ). If any other Pending or Confirmed DTCs were indicated in step  30, go to the indicated DTC'S TROUBLESHOOTING .

    NO  -If the HDS indicates FAILED, check for poor connections or loose terminals at the knock sensor and the PCM. If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE PCM ), then go to step  28. If the PCM was substituted, go to step  1. If the HDS indicates NOT COMPLETED, go to step  28.

scientia non olet · About LEMON Manuals