What does P0403 mean?
The exhaust gas recirculation (EGR) system feeds a small amount of exhaust back into the intake. That lowers combustion temperatures and cuts NOx emissions. This code means the computer found a problem with EGR flow or control.
The computer tried to control the part and saw an electrical fault, usually an open circuit.
Codes are a starting point. They tell you which test failed, not which part to replace. Check for other stored codes and fix those in a sensible order.
Symptoms
- Check engine light
- Pinging under load (insufficient flow)
- Rough idle or stalling (excessive flow or stuck-open valve)
- Failed emissions test
Common causes
- Open circuit in the solenoid or its wiring
- Unplugged or corroded connector
- Blown fuse feeding the component
- Failed component
How to diagnose P0403
- Check the fuse that feeds the component.
- Measure the component's resistance and compare it with the service spec.
- Check for power at the connector with the key on, and for a broken control wire back to the computer.
- Command the EGR valve with a scan tool and watch the position feedback.
- Check passages for carbon buildup.
How to fix it
- Clean the EGR valve and passages
- Replace the EGR valve
- Replace the EGR sensor
- Repair vacuum lines or wiring
Estimated repair cost
Likely repairs for P0403 run from about $150 to $1,500, depending on the cause.
| Repair | Typical range (parts + labor) |
|---|---|
| Diagnostic fee (scan + testing) | $100 - $200 |
| EGR valve/passage cleaning | $150 - $600 |
| EGR valve replacement (gasoline) | $250 - $700 |
| EGR valve replacement (diesel) | $400 - $1,500 |
These are rough US estimates for an independent shop in 2026, based on typical parts prices and standard labor times. Dealers, big trucks, luxury brands and high-cost areas often run higher. They are not quotes. Use the repair cost estimator to adjust for your vehicle.
How serious is P0403?
Moderate severity
Usually drivable. Fix it to avoid pinging and failed emissions tests.
P0403 FAQ
What does P0403 mean?
P0403 stands for "Exhaust Gas Recirculation "A" Control Circuit". The exhaust gas recirculation (EGR) system feeds a small amount of exhaust back into the intake.
Can I drive with a P0403 code?
Usually drivable. Fix it to avoid pinging and failed emissions tests.
How much does it cost to fix P0403?
It depends on the cause. The likely repairs for P0403 range from about $150 to $1,500 at an independent shop in the US, plus a diagnostic fee of roughly $100-$200. These are rough estimates; dealer prices and some vehicles run higher.
What is the most common cause of P0403?
The most common causes are: open circuit in the solenoid or its wiring; unplugged or corroded connector; blown fuse feeding the component.