DTC P0325: Knock Sensor Circuit Malfunction

Reset the PCM (see HOW TO RESET THE PCM ).
Start the engine. Hold the engine at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on, then let it idle.
Hold the engine at 3,000-4,000 rpm for at least 60 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 PCM.
Turn the ignition switch OFF.
Disconnect the knock sensor subharness connector (C161).
Disconnect the PCM connector C (31P).
Check for continuity between PCM connector terminal C22 and body ground.

Fig 1: Checking For Continuity Between PCM Connector Terminal C22 & Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES -Repair short in the wire between the PCM (C22) and the knock sensor subharness connector (C161).
2. NO -Go to step 8.
Connect knock sensor subharness connector (C161) terminal No. 1 to body ground with a jumper wire.

Fig 2: Connecting Knock Sensor Subharness Connector (C161) Terminal No. 1 To Body Ground With A Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between PCM connector terminal C22 and body ground.

Fig 3: Checking For Continuity Between PCM Connector Terminal C22 & 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 PCM (C22) and the knock sensor subharness connector (C161).
Check the knock sensor subharness between C161 and the knock sensor for an open or short. If it's OK, substitute a known-good knock sensor and recheck.
Is DTC P0325 indicated?
1. YES -Substitute a known-good PCM and recheck (see HOW TO SUBSTITUTE THE PCM FOR TESTING ). If the symptom/indication goes away, replace the original PCM.
2. NO -Replace the original knock sensor and/or the knock sensor subharness.