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 ).

Turn the ignition switch ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed between 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
Hold the engine speed between 3,000-4,000 RPM for at least 10 seconds.
Check for Temporary DTCs or 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.
Turn the ignition switch OFF.
Jump the SCS line with the HDS.
Disconnect the knock sensor 1P connector (see ECT SENSOR 2 REPLACEMENT ).
Disconnect PCM connector C (44P).
Check for continuity between PCM connector terminal C42 and body ground.

Fig 1: Checking Continuity Between PCM Connector Terminal C42 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Repair short in the wire between the PCM (C42) and the knock sensor, then go to step 14.

NO - Go to step 11.
Connect the knock sensor 1P connector terminal to body ground with a jumper wire.

Fig 2: Connecting Knock Sensor 1P Connector Terminal To Body Ground With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between PCM connector terminal C42 and body ground.

Fig 3: Checking Continuity Between PCM Connector Terminal C42 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to step 13.

NO - Repair open in the wire between the PCM (C42) and the knock sensor, then go to step 14.
Replace the knock sensor (see ECT SENSOR 2 REPLACEMENT ).
Reconnect all connectors.
Turn the ignition switch ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
Hold the engine speed between 3,000-4,000 RPM for at least 10 seconds.
Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0325 indicated?

YES - Go to step 21.

NO - Go to step 20.
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 Temporary DTCs or DTCs were indicated in step 19, go to the indicated DTCs troubleshooting.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the knock sensor and the PCM, then go to step 1. If the screen indicates NOT COMPLETED, go to step 18.
Update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ).
Hold the engine speed between 3,000-4,000 RPM for at least 10 seconds.
Check for Temporary DTCs or 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 22. If the PCM was substituted, go to step 1.

NO - Go to step 24.
Monitor the OBD STATUS for DTC P0325 in the DTCs MENU with the HDS.
Does the screen 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 Temporary DTCs or DTCs were indicated in step 23, go to the indicated DTCs troubleshooting.

NO - If the screen 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 22. If the PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, go to step 22.