P0203 Injector Circuit/Open - Cylinder 3
The engine computer detects an electrical fault in the injector circuit for cylinder 3.
Common causes
- Faulty injector for cylinder 3
- Damaged wiring or connector
- Open injector driver circuit
Symptoms
- Check engine light
- Misfire on cylinder 3
- Rough running
- Reduced power
What to check
- Inspect the injector connector
- Measure injector resistance
- Check for power and switching at the connector
Manufacturers may add their own detail to generic codes. If your vehicle shows a different description for P0203, follow the service information for that make and model.