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.

Real-world scan data

Seen in

1,634

scans in the past year

Found in

0.3%

of scans

0.5%

of scans that found faults

Appears alongside · share of P0325 scans

P0420in 37.9% of scans

P0130in 34.1% of scans

P2119in 33.7% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

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.

Read & clear P0325 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX