Fault in the cylinder 4 ignition coil primary/secondary circuit.
SYMPTOMS
- Check-engine light
- Misfire
- Rough idle
- Power loss
LIKELY CAUSES
- Failed ignition coil
- Coil wiring/connector fault
- Driver circuit fault in the ECM
DIAGNOSIS STEPS
- Check coil resistance and wiring
- Swap coil to confirm
- Check the driver circuit
- Replace coil
RELATED PARTS
- Ignition coil