Block of codes
P23xx codes: ignition coils and knock
This block brings together the codes from P2300 to P2339 in the glossary. Open yours to see what it means, its causes and whether you can keep driving.
Reviewed by Daniel Morales, founder of Reprorace SL, on
What this block covers
Ignition and misfire
Spark plugs and coils make the spark that burns the mixture in each cylinder. If a cylinder does not fire properly, the engine shakes and loses power, and unburnt fuel can damage the catalytic converter.
The 10 codes of the block
- P2300Ignition coil A, primary control circuit: signal low
- P2301Ignition coil A, primary control circuit: signal high
- P2302Ignition coil A, secondary circuit: malfunction
- P2303Ignition coil B, primary control circuit: signal low
- P2304Ignition coil B, primary control circuit: signal high
- P2305Ignition coil B, secondary circuit: malfunction
- P2336Cylinder 1: knock/combustion vibration above sensor threshold
- P2337Cylinder 2: knock/combustion vibration above sensor threshold
- P2338Cylinder 3: knock/combustion vibration above sensor threshold
- P2339Cylinder 4: knock/combustion vibration above sensor threshold
Other blocks
Read your car's fault codes on your phone
With an ECO-LITE in the OBD socket you see the codes in your account, with the data captured when the fault happened, and your workshop can check them remotely, always with your permission.
Keep reading
- OBD fault codes: what each one means
- Check engine light on: what to do
- How to read and clear your car's fault codes
- Will your car pass its MOT or inspection with the engine light on?
- Wi-Fi OBD2 reader: which one to choose
- Reading fault codes by car make
- Remote OBD diagnostics: what it is, how it works and what it can't do
- Vehicle diagnostics glossary