P0327

Knock/Combustion Vibration Sensor A Circuit Low

Ignition / knock sensor Generic OBD-II Medium

What it means

P0327 means the knock sensor's circuit is producing a low (or open) signal voltage. The knock sensor listens for detonation so the ECM can retard ignition timing to protect the engine. With a low signal, the ECM can't trust the sensor and typically pulls timing as a precaution — the car keeps running but may feel a little softer and use slightly more fuel. It's usually a bad sensor or wiring, not the engine itself.

Medium

Can I keep driving? Safe to drive — the car runs, but the ECM may pull timing as a precaution, softening performance and economy; fix it to restore full spark timing.

Real-world scan data

Seen in

1,711

scans in the past year

Found in

0.3%

of scans

0.5%

of scans that found faults

Appears alongside · share of P0327 scans

P0420in 25.0% of scans

P0300in 24.6% of scans

P0328in 23.5% 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 or sluggish acceleration (ECM retards timing defensively)
Slightly worse fuel economy
Possible engine knock or ping under load if timing isn't protected

Common causes

Most likely first

Failed knock sensor giving a low/open signal — most commonLikely
Damaged wiring or a poor connection in the knock-sensor circuitCommon
Loose or corroded sensor connectorCommon
Rarely, an ECM faultLess often

How to diagnose & fix

Work through it in order

Inspect the knock-sensor connector and wiring for damage, corrosion, or an open — a common cause of a low signal.
Measure the sensor's resistance and compare to the service-manual spec.
Confirm the sensor is torqued correctly to the block; a loose sensor reads poorly.
Replace the knock sensor if it's out of spec, then clear and re-test.

FAQ

Quick answers

Is it safe to drive with P0327?+

Yes. Without a valid knock signal the ECM usually retards ignition timing to stay safe, so you may feel slightly less power but no immediate harm. Fixing it restores normal timing and efficiency.

Can I just clear P0327?+

It will return once the ECM re-checks the circuit if the sensor or wiring is still faulty. Repairing the connection or replacing the sensor is what clears it for good.

Read & clear P0327 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