P0327: Knock Sensor 1 Circuit Low (Bank 1 or Single Sensor)
P0327 means Knock Sensor 1 Circuit Low (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 signal voltage is lower than the minimum the module expects. Typical causes are a short to ground, an open in the reference or signal wire, or a failed sensor.
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 P0327
- 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 P0327
Related codes
- P0326 Knock Sensor 1 Circuit Range/Performance (Bank 1 or Single Sensor)
- P0328 Knock Sensor 1 Circuit High (Bank 1 or Single Sensor)
- P0325 Knock Sensor 1 Circuit (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.