P0325: Knock Sensor 1 Circuit (Bank 1 or Single Sensor)
P0325 means Knock Sensor 1 Circuit (Bank 1 or Single Sensor). The knock sensor on bank 1 (the side with cylinder 1) listens for detonation (knock) so the engine computer can retard ignition timing. The control module has detected a fault in the circuit itself, such as an open circuit, a short, or a signal outside the electrical limits it expects.
Can I keep driving? Drivable with care. Diagnose soon: performance, economy or other components can be affected.
Common symptoms
- Check engine light on
- Reduced power and acceleration (timing retarded as a precaution)
- Worse fuel economy
- Possible audible pinging under load
Possible causes
- Failed knock sensor
- Damaged wiring or connector (often under the intake manifold on V engines)
- Sensor mounting bolt at the wrong torque
- Actual engine knock from low-octane fuel or carbon build-up
- Engine mechanical noise
How to diagnose P0325
- Check the sensor connector and wiring.
- Check the sensor is torqued to specification: it is sensitive to mounting torque.
- Use the fuel grade the manufacturer specifies.
- Listen for actual mechanical knocking.
What the code means, digit by digit
Generic codes have the same definition on every OBD-II vehicle (petrol cars from model year 1996 in the US, 2001 in the EU; diesels later). Manufacturers can add their own enhanced codes; those are not listed here.
Symptoms linked to P0325
Related codes
- P0326 Knock Sensor 1 Circuit Range/Performance (Bank 1 or Single Sensor)
- P0327 Knock Sensor 1 Circuit Low (Bank 1 or Single Sensor)
- P0328 Knock Sensor 1 Circuit High (Bank 1 or Single Sensor)
- P0330 Knock Sensor 2 Circuit (Bank 2)
- P0332 Knock Sensor 2 Circuit Low (Bank 2)
- P0333 Knock Sensor 2 Circuit High (Bank 2)
General guidance only. Fault codes describe what the engine computer saw, not which part failed: confirm with testing before replacing parts, and follow the vehicle's service information.