OBD-II code guide
P0203 Injector Circuit Cylinder 3
P0203 means the fuel injector circuit for cylinder 3 has an electrical fault.
What it means
Cylinder 3 may have an injector control or circuit issue.
Common symptoms
- Misfire
- Rough idle
- Hesitation
- Fuel smell
- Check engine light
Likely causes
- Injector circuit open
- Injector circuit short
- Faulty injector
- Loose connector
- Damaged harness
First checks
- Inspect cylinder 3 injector connection.
- Check for related P0303.
- Confirm injector pulse and resistance if applicable.
- Avoid continued driving if the light flashes.