P03FF
Ignition L Control Signal Circuit High
Generic OBD-II
Common symptoms
What you'll notice
- Check and replace ignition coil
- Inspect and repair damaged or loose wiring in ignition system
- Replace faulty ignition control module
- Check and replace ignition switch
- Inspect and repair any issues with the Engine Control Unit (ECU)
Common causes
Most likely first
- Faulty ignition coil
- Defective ignition control module
- Wiring issue in the ignition system
- Malfunctioning ignition switch
- Faulty engine control unit (ECU)
How to diagnose & fix
Work through it in order
- Engine misfire
- Rough or inconsistent engine idling
- Difficulty starting the engine
- Poor fuel efficiency
- Illuminated check engine light
Read & clear P03FF yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.