What P0325 Means
The knock sensor, which listens for abnormal engine vibrations that indicate detonation ('knocking'), has an electrical fault or isn't sending a usable signal.
Common Causes
- Faulty knock sensor
- Damaged or corroded sensor wiring
- Loose sensor mounting
Symptoms You Might Notice
- Usually minimal drivability impact on its own
- Engine may run in a more conservative, less powerful timing mode
- Check engine light on
- Reduced fuel economy in some cases
What to Check First
- 1
Check the sensor's mounting torque and wiring connection for damage
- 2
Test the sensor's signal output with a scan tool while lightly tapping near it (with the engine off) to confirm it's detecting vibration
- 3
Replace the sensor if it's not producing a signal