Part and system guide
Ignition Coils
Ignition coils turn low battery voltage into the high voltage needed to fire spark plugs.
What it does
Supply spark energy to one or more cylinders.
Failure signs
- Misfire under load
- Rough idle
- Flashing check engine light
- Poor fuel economy
- Hard starting
Maintenance notes
- Diagnose with codes and cylinder data before replacing all coils.
- Check plug condition because worn plugs stress coils.
- Keep coil boots dry and properly seated.