P0351 Ignition Coil A Primary Control Circuit/Open
What does P0351 mean?
P0351 — Ignition Coil A Primary Control Circuit/Open. This is an OBD-II diagnostic trouble code a scanner retrieves when your vehicle's computer detects ignition coil a primary control circuit/open. The level of risk depends on how the vehicle is currently running and how long you've been driving with the light on.
Common causes of P0351
- Open or shorted coil wiring
- Failed ignition coil
- Damaged coil connector
- Faulty PCM coil driver
- Crank or cam sensor fault affecting coil firing
How to fix P0351
- Swap the coil to another cylinder to see if the code follows
- Measure coil primary resistance and inspect the connector
- Check for a trigger signal on the coil low side with a scope
- Verify the coil has power with the key on
- Replace the coil or repair wiring as identified