P2344: Cylinder 9 Above Knock/Combustion Vibration Sensor Threshold
What to do
Avoid heavy loads and ease off if you hear a rattle. Check the specified fuel grade first, and ask how many cylinders are reporting — one points at that cylinder, several at something the engine shares.
What this code means
Cylinder 9 is requiring more knock protection than normal. The mechanism is at P2336, the fuel grade test at P2337 and the shared-cause discriminator at P2341.
Likely causes
Start here
- Incorrect or low octane fuel · easy
- Carbon deposits in the combustion chamber · moderate
- Clogged fuel injectors · moderate
Less common
- Faulty knock sensor · moderate
- Low coolant level · easy
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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