P0327 Knock sensor 1 circuit low (bank 1 or single sensor)
What P0327 means
The knock sensor is a small microphone bolted to the engine block that listens for detonation. P0327 means its signal voltage is below the expected range, so the computer can no longer trust it. To protect the engine it usually retards the ignition timing, which costs some power and fuel economy.
P0327 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
- 80–300 €
- Workshop time
- 1.5–6 h
- Repair difficulty
- Hard
- DIY possible
- No
- 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
- Slightly reduced power, especially under load
- Higher fuel consumption
- Possible pinging or knocking noise when accelerating
Common causes
- Failed knock sensor
- Sensor bolt loose or tightened to the wrong torque
- Damaged or corroded wiring or connector (often under the intake manifold)
- Short to ground in the sensor signal wire
- Engine control unit fault (rare)
Can I keep driving with P0327?
You can drive, but have it repaired within one or two weeks. Avoid heavy loads and use the correct fuel octane, because the engine has lost its knock protection.
What to check first
- Read the freeze-frame data and check whether the code returns immediately or only under load
- Inspect the knock sensor connector and harness for corrosion, oil contamination or chafing
- Measure the sensor resistance and signal wire continuity against the workshop specification
- Replace the sensor if faulty, clean the mounting surface and tighten it to the specified torque
Related codes
- P0326 Knock sensor A circuit range/performance (bank 1 or single sensor)
- P0328 Knock sensor A circuit high (bank 1 or single sensor)
- P0325 Knock sensor A circuit (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
- P0336 Crankshaft position sensor A circuit range/performance
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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