P2336
Cylinder 1 Above Knock/Combustion Vibration Sensor Threshold
Ignition system
Generic OBD-II
Medium
What it means
P2336 means the knock sensor readings for cylinder 1 exceeded the computer's allowed threshold. This can indicate genuine engine knock (detonation) or a faulty knock sensor circuit. In response the computer may retard ignition timing to protect the engine, which reduces power. It is worth diagnosing because real detonation can damage internal parts.
Medium
Can I keep driving? Usually drivable, but the computer may pull timing to protect the engine, costing power. Avoid hard acceleration and heavy loads until it is checked.
Common symptoms
What you'll notice
- Check-engine light on
- Reduced power, especially under acceleration
- Audible knock or pinging in some cases
- Slightly higher fuel consumption
Common causes
Most likely first
- Genuine engine knock/detonation (low-octane fuel, carbon buildup, overheating)Likely
- Failed or noisy knock sensor for cylinder 1Common
- Corroded or loose knock sensor connector or wiringCommon
- Lean condition or over-advanced timingLess often
- Failed PCM/ECM (less common)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check whether real knock is present (fuel quality, load, temperature).
- Try a tank of the correct-octane fuel and confirm the engine is not overheating.
- Inspect the knock sensor connector and wiring for corrosion or looseness.
- Test the knock sensor's signal against spec; replace it if faulty.
- Address any underlying lean or timing cause, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2336?+
Light driving is usually fine, but sustained detonation can damage pistons and rings. Avoid hard acceleration and get it diagnosed, since the code can reflect real knock, not just a sensor fault.
Can I just clear P2336?+
It will return if actual knock is occurring or the sensor circuit is faulty. Fix the cause first.
Related codes
Often seen with P2336
Read & clear P2336 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