P0331

Knock/Combustion Vibration Sensor B Circuit Range/Performance

Q: Is it safe to drive with P0331?

Yes, short-term. The engine may run slightly softer because timing is retarded for protection, but this code alone won't leave you stranded. Fix it to restore full power and economy.

Q: Can I just clear P0331?

It will clear, but returns until the knock sensor or its wiring is repaired.

Ignition / knock sensor Generic OBD-II Medium

What it means

P0331 means the second knock sensor's signal is outside the expected range. The knock sensor lets the computer detect engine "knock" and pull ignition timing to protect the engine. Contrary to some templated descriptions, this code does not cause a no-start — it usually just costs a little power and economy until repaired.

Medium

Can I keep driving? Safe to drive short-term; the engine may retard timing for protection, giving slightly less power and economy, but it won't stall or fail to start from this code.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

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
Slightly reduced power or acceleration (timing pulled for safety)
Small drop in fuel economy
Possible pinging under hard acceleration if knock goes undetected

Common causes

Most likely first

Faulty knock sensor BLikely
Open, shorted, or chafed wiring in the sensor circuitCommon
Loose or corroded electrical connectorCommon
Failed engine control module (rare)Less often

How to diagnose & fix

Work through it in order

Read freeze-frame data and confirm the code is knock sensor B (bank 2).
Inspect the knock sensor connector and wiring for damage or corrosion.
Check the sensor's resistance and signal against manufacturer spec; ensure the mounting bolt is torqued (a loose sensor gives false readings).
Replace the knock sensor if it's out of spec with good wiring. Clear and re-test.

FAQ

Quick answers

Is it safe to drive with P0331?+

Yes, short-term. The engine may run slightly softer because timing is retarded for protection, but this code alone won't leave you stranded. Fix it to restore full power and economy.

Can I just clear P0331?+

It will clear, but returns until the knock sensor or its wiring is repaired.

Read & clear P0331 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