OBD-II · Engine and powertrain (P)
P0403
EGR control circuit fault
What it means
The electrical control circuit for the EGR valve motor or solenoid is faulty.
Symptoms
- engine warning light
- possibly reduced power (limp mode)
- rough idle or hesitation
- more smoke than usual
Likely causes, most likely first
| No. | Cause |
|---|---|
| 01 | failed EGR valve motor or solenoid |
| 02 | wiring open or short |
| 03 | connector corrosion or oil contamination |
| 04 | blown fuse |
| 05 | engine computer driver fault (rare) |
What to check, step by step
- 01Inspect the EGR connector for corrosion and oil.
- 02Check the fuse and supply voltage.
- 03Measure motor/solenoid resistance against specification.
- 04Check wiring continuity to the engine computer.
- 05Replace the valve if the actuator is open or shorted.