P0326

Knock/Combustion Vibration Sensor A Circuit Range/Performance

Ignition timing Generic OBD-II Medium

What it means

P0326 means the knock sensor's signal is outside the range the ECM expects. That sensor listens for engine knock so the computer can trim ignition timing; when its signal is unreliable, the ECM retards timing conservatively and you may lose a little power. This is a sensor-circuit fault — it does not stop the engine from starting or running.

Medium

Can I keep driving? Usually driveable — the ECM retards timing as a precaution, so expect slightly less power and economy but no immediate risk to a healthy engine.

Real-world scan data

Seen in

610

scans in the past year

Found in

0.1%

of scans

0.2%

of scans that found faults

Appears alongside · share of P0326 scans

P0300in 18.2% of scans

P0301in 12.1% of scans

P0302in 10.8% 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
Slightly reduced power or acceleration
Audible knocking or pinging under load (timing can no longer be trimmed accurately)
Small drop in fuel economy

Common causes

Most likely first

Failed knock sensor or one reading out of rangeLikely
Damaged wiring or connector in the sensor circuitCommon
Loose or corroded electrical connectionCommon
Genuine engine knock (carbon build-up, low octane, lean condition) the sensor is reportingLess often
ECM fault (rare — rule out sensor and wiring first)Less often

How to diagnose & fix

Work through it in order

Scan and read freeze-frame data to confirm the fault is the knock-sensor circuit's signal, not a mechanical knock.
Inspect the sensor connector and wiring — these sensors sit on the block and their harness is prone to heat and chafing.
Check the knock sensor's resistance and mounting torque against spec.
Rule out real detonation from low-octane fuel, carbon, or a lean mixture.
Replace the knock sensor if it is out of range with good wiring. Clear and re-test.

FAQ

Quick answers

Is it safe to drive with P0326?+

Generally yes, short-term. The ECM pulls timing to protect the engine, so you lose a little power. Fix it before hard driving or towing.

Can I just clear P0326?+

It will return once the ECM re-tests the knock circuit. This is a sensor/wiring fault that needs repair, not just a reset.

Read & clear P0326 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