P0403 code meaning
EGR A Control Circuit/Open
Powertrain system Generic code P04xx codes Check engine light
What P0403 means
Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. P0403 concerns the electrical drive of the EGR valve – solenoid, stepper motor, DC motor or vacuum regulator. The module checks the output and sets the code for an open circuit (GM: above 200 kΩ, MIL after two trips; Ford after 4 s, MIL after two trips). Newer systems report shorts separately as P0489 (low) and P0490 (high); Ford and older GM systems include them in P0403. EGR is then switched off for the rest of the trip.
P0403 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.5 to 2.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0403
- Check engine light on
- EGR switched off: pinging (gasoline) or higher NOx
- Usually no loss of power
Common causes of P0403
- Most likelyConnector at the EGR valve corroded or loose
- PossibleBroken control or supply wire
- PossibleCoil or motor in the EGR valve burnt out
- Less likelyDriver in the engine module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
EGR valveEGR valve actuatorEGR wiringEngine control module
What each part of P0403 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| 03 | The exact fault in that area. |
What to do next
- Note P0403 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0403
What does P0403 mean?
P0403 means "EGR A Control Circuit/Open". Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. It is a generic code, so it means the same on every make.
Is it safe to drive with P0403?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P0403 fail an emissions test?
Yes, it can. P0403 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0403 to fix?
Difficulty: easy. A typical repair takes 0.5 to 2.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0403 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.