DTC P0325: Knock Sensor Circuit Malfunction Honda S2000 AP1

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

Scheme 87

Scheme 88

Scheme 89

1. Reset the ECM (see «HOW TO RESET THE ECM»(ref-221328-S42309504302006022400000) ).
2. 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.
3. Hold the engine speed at 3,000-4,000 RPM for 10 seconds. Is DTC P0325 indicated? YES - Go to step 4. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the knock sensor and at the ECM.
4. Turn the ignition switch OFF.
5. From underneath the vehicle, reach above the front of the starter motor, and disconnect the knock sensor 1P connector.
6. Disconnect ECM connector C (31P), then check for continuity between ECM connector terminals C22 and body ground. Is there continuity? YES - Repair short in the wire between the ECM (C22) and the knock sensor. NO - Go to step 7.
7. Connect the knock sensor 1P connector terminal body ground with a jumper wire.
8. Check for continuity between ECM connector terminal C22 and body ground. Is there continuity? YES - Go to step 9. NO - Repair open in the wire between the ECM (C22) and the knock sensor.
9. Substitute a known-good knock sensor and recheck. Is DTC P0325 indicated? YES - Substitute a known-good ECM (see «HOW TO SUBSTITUTE THE ECM FOR TESTING PURPOSES»(ref-221328-S04997151962006022400000) ) and recheck. If the symptom/indication goes away, replace the original ECM (see «ECM REPLACEMENT»(ref-221329-S30667517252006022400000) ). NO - Replace the original knock sensor.