| CAUTION | If ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION. |
Circuit Description
Knock sensors are located on either side of cylinder block under intake manifold. Knock sensor generates voltage when engine block vibrates due to knocking. DTC P0325 is for bank that includes cylinder No. 1. DTC P0330 is for bank that does not include cylinder No. 1. DTC is set when there is no knock sensor signal to ECM with engine speed 1700-5400 RPM. Possible causes are
- Knock sensor circuit is open or shorted.
- Defective or loose knock sensor.
- Defective ECM.
Diagnostic Aids
Normal mode vibration frequency of knock sensors are 8.1 kHz. Using scan tool, read freeze frame data. Freeze frame records engine conditions when malfunction is detected.