P0403 EGR A control circuit/open
What P0403 means
The engine control unit has found an open or faulty circuit when it tries to drive the exhaust gas recirculation (EGR) valve. The valve can no longer be controlled, which mainly affects emissions and can cause poor running.
P0403 is a generic SAE J2012 code: it means the same on every make. The exact cause still depends on the car, so read the freeze-frame data before replacing parts.
At a glance
- Severity
- Medium
- Typical repair cost
- 80–500 €
- Workshop time
- 0.5–2.5 h
- Repair difficulty
- Medium
- DIY possible
- No
- Check engine light
- Yes
- Affects emissions test
- Yes
Parts and labour at an independent workshop in Europe. Main dealers charge more; the cause decides the bill, not the code.
Symptoms
- Check engine light on
- Rough idle or hesitation
- Higher emissions, possible technical inspection failure
- Reduced power on some diesels
Common causes
- Failed EGR valve motor or solenoid coil
- Loose, corroded or oil-soaked connector at the EGR valve
- Broken wire between the ECU and the valve
- Blown fuse or relay in the EGR supply circuit
Can I keep driving with P0403?
You can keep driving, but have it checked within one to two weeks. Emissions will be higher and the car may fail its technical inspection.
What to check first
- Inspect the EGR valve connector for corrosion, oil or bent pins
- Check the fuse and the supply voltage at the connector
- Measure the valve coil or motor resistance against the specification
- Repair the wiring or replace the EGR valve, then clear the code and test drive
Related codes
- P0402 EGR flow excessive detected
- P0404 EGR A control circuit range/performance
- P0401 Exhaust gas recirculation (EGR) A flow insufficient
- P0405 EGR sensor A circuit low
- P0400 Exhaust gas recirculation (EGR) A flow malfunction
- P0406 EGR sensor A circuit high
- P0410 Secondary air injection system A
- P0411 Secondary air injection system incorrect flow detected
Data: TORKO fault-code catalogue, built on OBDex (CC0-1.0) and reviewed against workshop practice. Informational only — it does not replace a diagnosis by a mechanic.
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