P0325
Knock/Combustion Vibration Sensor A Circuit
Ignition / knock sensor
Generic OBD-II
Medium
What it means
P0325 means the ECM has detected a fault in the knock sensor circuit. The knock sensor listens for detonation ("pinging") and lets the ECM fine-tune ignition timing. With it offline, the ECM retards timing as a safety measure, so you lose a little power and economy. The car drives, but it should be fixed before hard use.
Medium
Can I keep driving? Yes, but gently — with the knock sensor offline the ECM pulls timing, so you lose some power; hard acceleration risks knock, so avoid heavy loads until fixed.
Common symptoms
What you'll notice
- Check-engine light on
- Reduced power and sluggish acceleration
- Slightly worse fuel economy
- Audible knock or pinging under load in some cases
Common causes
Most likely first
- Failed knock sensorLikely
- Damaged wiring or a poor connector at the sensorCommon
- Loose or corroded electrical connection in the circuitCommon
- Rarely, a faulty ECMLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data, then locate the knock sensor (usually on the engine block) and inspect its connector and wiring for damage or corrosion.
- Clean or repair any loose or corroded connections and re-test.
- Measure the sensor's resistance against spec; replace the knock sensor if it's out of range or open.
- If wiring and sensor are good, check the circuit back to the ECM before considering the module.
FAQ
Quick answers
Is it safe to drive with P0325?+
Short-term yes, but drive gently. Without knock detection the ECM retards timing as a precaution, so you lose power, and heavy throttle raises the risk of damaging detonation.
Can I just clear P0325?+
It returns once the ECM re-tests the circuit unless the sensor, wiring, or connection is repaired.
Related codes
Often seen with P0325
Read & clear P0325 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX