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 with the HDS (see ECM RESET ).
Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
Hold the engine speed at 3,000-4,000 rpm for 10 seconds.
Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0325 indicated?
1. YES - Go to step 5.
2. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the knock sensor and the ECM.
Turn the ignition switch OFF, and wait for 10 seconds.
Disconnect the knock sensor 1P connector.
Disconnect ECM connector C (31P), then check for continuity between ECM connector terminal C22 and body ground.

Fig 1: Checking Continuity Between ECM Connector Terminal 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 8.
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 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 10.
2. NO - Repair open in the wire between the ECM (C22) and the knock sensor.
Substitute a known-good knock sensor.
Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0325 indicated?
1. YES - Update the ECM if it does not have the latest software, or substitute a known-good ECM; 2000-2001 M/T models (see HOW TO SUBSTITUTE THE ECM FOR TESTING PURPOSES (2000-2001 M/T MODELS) ), 2002-2006 M/T models and CVT model (see ECM UPDATING AND SUBSTITUTION FOR TESTING-2002-2006 M/T MODELS AND CVT MODEL ), then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM (see ECM REPLACEMENT ).
2. NO - Replace the original knock sensor (see KNOCK SENSOR REPLACEMENT ).