P0403 on Peugeot: How to Diagnose & Fix
Exhaust Gas Recirculation Circuit Malfunction
1 Peugeot model · 1 documented issue · $200-$600 repair
P0403 on Peugeot by model: symptoms, diagnosis and fix
The exhaust gas recirculation valve on diesel 308 models becomes clogged with carbon deposits, causing rough idle and poor performance. The electrically actuated valve sticks in the open or closed position.
Common Symptoms
- Rough idle
- Black exhaust smoke
- Loss of power
- Check engine light
How to Fix
Clean or replace the EGR valve. Install an EGR cooler bypass blanking kit if permitted in your region. Update the ECU software to revised EGR control maps.
Sources for this issue (1)
P0403 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0403 mean on a Peugeot?
P0403 stands for "Exhaust Gas Recirculation Circuit Malfunction." This emissions code indicates a malfunction in the exhaust gas recirculation (EGR) control circuit. The EGR system routes a small amount of exhaust back into the intake to lower combustion temperatures and reduce nitrogen-oxide emissions, and the computer commands the EGR valve open and closed through this circuit. The code sets when the electrical control signal to the EGR valve or its solenoid is out of the expected range — for example, an open, short, or a commanded change that doesn't produce the right feedback. It generally points to an electrical or wiring problem in the EGR control circuit, or the EGR valve/solenoid itself, rather than carbon clogging alone. On Peugeot it is documented across 1 model: 308.
What are the most common causes of P0403?
The most common causes of P0403 are: Faulty EGR valve or EGR solenoid, Damaged wiring or connector in the EGR control circuit, Open or short in the EGR control wiring, Corroded or loose EGR connector, Blown fuse or lost power supply to the EGR circuit, Carbon buildup binding the EGR valve, Faulty engine control module or driver circuit. The specific cause varies by vehicle.
How much does it cost to fix P0403 on a Peugeot?
Published repair estimates on Peugeot range from $200 to $600 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.