P0330
Knock/Combustion Vibration Sensor B Circuit
Knock sensor
Generic OBD-II
Medium
What it means
P0330 means the engine computer has detected a fault in the circuit for the second (bank 2) knock sensor. The knock sensor lets the ECM detect engine knock and adjust timing; when its signal is missing or out of range, the ECM often retards timing as a safeguard, which can slightly reduce power and fuel economy.
Medium
Can I keep driving? Drivable — the engine still runs, but the ECM may retard ignition timing as a precaution, costing some power and fuel economy until it's fixed.
Common symptoms
What you'll notice
- Check-engine light on
- Slight loss of power or sluggish acceleration
- Reduced fuel economy
- Often no noticeable symptom other than the warning light
Common causes
Most likely first
- Failed knock sensor 'B'Likely
- Damaged wiring or a poor connector in the knock-sensor circuitCommon
- Corroded or loose electrical connections / groundCommon
- Failed engine control module (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and inspect the knock-sensor connector and wiring (often tucked under the intake) for damage or corrosion.
- Check the sensor's resistance and its circuit continuity to the ECM.
- Confirm the sensor is torqued correctly to the block — a loose sensor gives false readings.
- Replace the knock sensor if testing confirms it. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0330?+
Yes, generally. A failed knock sensor doesn't cause knock — it just leaves the ECM unable to detect it, so it plays safe by pulling timing. Fix it to restore full power and economy.
Can I just clear P0330?+
You can, but it returns until the sensor or its wiring is repaired.
Related codes
Often seen with P0330
Read & clear P0330 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