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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), or press the engine start/stop button to select the ON mode.
  2. Clear the DTC with the HDS.
  3. Start the engine. Hold the engine speed at 3, 000 RPM without load (A/T in P or N, M/T in neutral) 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 ECM/PCM. ■

  6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  7. Jump the SCS line with the HDS.
  8. Disconnect the knock sensor subharness 1P connector.
  9. Disconnect ECM/PCM connector C (49P).
  10. Check for continuity between ECM/PCM connector terminal C47 and body ground.
    Fig 1: Checking Continuity Between ECM/PCM Connector Terminal C47 And Body Ground
    G08069396Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

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

    NO  - Go to step 11.

  11. Connect the engine wire harness C104 1P connector terminal to body ground with a jumper wire.
    Fig 2: Connecting Engine Wire Harness C104 1P Connector Terminal To Body Ground With Jumper Wire
    G08069397Courtesy of AMERICAN HONDA MOTOR CO., INC.
  12. Check for continuity between ECM/PCM connector terminal C47 and body ground.
    Fig 3: Checking Continuity Between ECM/PCM Connector Terminal C47 And Body Ground
    G08069398Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step 13.

    NO  - Repair open in the wire between the ECM/PCM (C47) and the engine wire harness (C104 connector), then go to step  20.

  13. Remove the jumper wire from the engine wire harness.
  14. Remove the intake manifold (see REMOVAL ), 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
    G08069399Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

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

  18. Replace the knock sensor .
  19. Install the injector base (see INJECTOR BASE REMOVAL AND INSTALLATION ), and the intake manifold (see INSTALLATION ).
  20. Reconnect all connectors.
  21. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
  22. Reset the ECM/PCM with the HDS.
  23. Do the ECM/PCM idle learn procedure (see ECM/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 ECM/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 screen 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 screen indicates FAILED, check for poor connections or loose terminals at the knock sensor and the ECM/PCM, then go to step  1. If the screen indicates NOT COMPLETED, go to step  24.

  27. Update the ECM/PCM  if it does not have the latest software (see ECM/PCM Update ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ).
  28. Start the engine. Hold the engine speed at 3, 000 RPM without load (A/T in P or N, M/T in neutral) 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 ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then go to step  28. If the ECM/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 screen indicate PASSED? 

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

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

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