DTC P0325: Knock Sensor Circuit Malfunction

NOTE: Before you troubleshoot, record all freeze data and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Reset the ECM (see HOW TO RESET THE ECM ).
Start the engine. Hold the engine speed at 3,000 RPM without load (in neutral) until the radiator fan comes on, then let it idle.
Hold the engine speed at 3,000-4,000 RPM for 10 seconds.
Is DTC P0325 indicated?
1. YES - Go to step 4.
2. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the knock sensor and at the ECM.
Turn the ignition switch OFF.
From underneath the vehicle, reach above the front of the starter motor, and disconnect the knock sensor 1P connector.
Disconnect ECM connector C (31P), then check for continuity between ECM connector terminals C22 and body ground.

Fig 1: Checking Continuity Between ECM Connector Terminals C22 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Repair short in the wire between the ECM (C22) and the knock sensor.
2. NO - Go to step 7.
Connect the knock sensor 1P connector terminal body ground with a jumper wire.

Fig 2: Connecting Knock Sensor 1P Connector Terminal Body Ground With A Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between ECM connector terminal C22 and body ground.

Fig 3: Checking Continuity Between ECM Connector Terminal C22 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Go to step 9.
2. NO - Repair open in the wire between the ECM (C22) and the knock sensor.
Substitute a known-good knock sensor and recheck.
Is DTC P0325 indicated?
1. YES - Substitute a known-good ECM (see HOW TO SUBSTITUTE THE ECM FOR TESTING PURPOSES ) and recheck. If the symptom/indication goes away, replace the original ECM (see ECM REPLACEMENT ).
2. NO - Replace the original knock sensor.