P0203 on Audi: How to Diagnose & Fix
Injector Circuit/Open - Cylinder 3
1 Audi model · 1 documented issue · $1,500-$4,000 repair
P0203 on Audi by model: symptoms, diagnosis and fix
The FSI direct-injection injectors shared across the VAG family (Audi/VW/Porsche) are a documented R8 failure point. Injectors can stick open or closed; a stuck-open injector dumps raw fuel into the cylinder and can wash down the bore, while a stuck-closed injector starves the cylinder. One well-known r8talk case had 6 of 8 injectors fail on a 2008 V8 at only 14,000 miles. Symptoms overlap with coil failure (misfires), so proper diagnosis is important, and carbon buildup on the injector tips is a contributing factor.
Common Symptoms
- Persistent cylinder misfire after coil replacement
- Rough running and reduced power
- Hard starting or stalling after start
- Fuel smell or fuel-trim faults
- Check-engine light
How to Fix
Confirm the failing cylinder with misfire and fuel-trim data and, where possible, injector-specific fault codes rather than replacing coils blindly. Replace the failed injector(s) with OEM FSI units; many owners replace as a bank or full set given shared age and mileage, and clean or address intake-valve carbon at the same service. Expect roughly $2,900 for a multi-injector job including labor per owner reports.
Sources for this issue (1)
P0203 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 P0203 mean on a Audi?
P0203 stands for "Injector Circuit/Open - Cylinder 3." This code means the Engine Control Module detected an electrical problem (open circuit or out-of-range resistance) in the fuel injector control circuit for cylinder 3. The ECM pulses each injector electrically and watches the circuit to verify it is operating. P0203 means the expected feedback for cylinder 3's injector is missing or abnormal, so that cylinder may not be fueling properly. The typical result is a misfire, rough idle, and reduced performance traceable to cylinder 3. On Audi it is documented across 1 model: R8.
What are the most common causes of P0203?
The most common causes of P0203 are: Damaged or corroded injector connector at cylinder 3, Open or shorted wiring in the injector control circuit, Failed (electrically open) fuel injector on cylinder 3, Loose or backed-out connector pin, Poor ground or power feed to the injector, Faulty injector driver inside the ECM/PCM, Chafed harness causing intermittent open. The specific cause varies by vehicle.
How much does it cost to fix P0203 on a Audi?
Published repair estimates on Audi range from $1,500 to $4,000 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.
Looking for P0203 on a different make?
View P0203 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.