P0326 Knock sensor A circuit range/performance (bank 1 or single sensor)
What P0326 means
Knock sensor A is sending a signal, but it is too weak or too strong for the current engine speed and load. The engine computer cannot rely on it to detect knock, so it retards ignition timing as a precaution.
P0326 is a generic SAE J2012 code: it means the same on every make. The exact cause still depends on the car, so read the freeze-frame data before replacing parts.
At a glance
- Severity
- Medium
- Typical repair cost
- 50–400 €
- Workshop time
- 0.5–2 h
- Repair difficulty
- Medium
- DIY possible
- Yes
- Check engine light
- Yes
- Affects emissions test
- Yes
Parts and labour at an independent workshop in Europe. Main dealers charge more; the cause decides the bill, not the code.
Symptoms
- Check engine light on
- Reduced power from retarded ignition timing
- Higher fuel consumption
- Possible audible pinging under load
Common causes
- Knock sensor loose or incorrectly torqued
- Damaged wiring or high resistance in the connector
- Excessive mechanical noise: loose heat shields, worn valvetrain or other engine noise
- Real knock from low-octane fuel or carbon deposits
- Failed knock sensor
Can I keep driving with P0326?
You can drive, but have it checked within one to two weeks. Use the correct fuel grade and avoid heavy load or full throttle, because knock protection is reduced.
What to check first
- Check the sensor mounting bolt torque and the connector.
- Listen for mechanical noises such as rattling heat shields or valvetrain noise.
- Confirm the correct fuel grade is being used.
- Test the sensor and wiring; replace the sensor if it is faulty.
Related codes
- P0327 Knock sensor 1 circuit low (bank 1 or single sensor)
- P0325 Knock sensor A circuit (bank 1 or single sensor)
- P0328 Knock sensor A circuit high (bank 1 or single sensor)
- P0320 Ignition/distributor engine speed input circuit
- P0330 Knock sensor B circuit (bank 2)
- P0332 Knock sensor B circuit low (bank 2)
- P0335 Crankshaft position sensor A circuit
- P0316 Engine misfire detected on start-up (first 1,000 revolutions)
Data: TORKO fault-code catalogue, built on OBDex (CC0-1.0) and reviewed against workshop practice. Informational only — it does not replace a diagnosis by a mechanic.
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