P3652critical severityPowertrain
GDI Fuel Rail Pressure Exceeded Maximum Limit
on 2015 Audi R8 5.2L V10 · AWD
What this code means
The fuel rail pressure has exceeded the maximum safe operating pressure. The pressure relief valve may have activated.
Symptoms
- Check Engine Light
- Fuel smell from engine
- Rough running
- Fuel injector damage risk
- Possible fuel leak at high pressure fittings
- Engine running rich
Common causes
- Pressure relief valve failure
- Fuel pressure regulator stuck
- High-pressure pump stuck in max output
- Blocked fuel return line
- PCM commanding excessive pressure
Diagnostic steps
- Read fuel rail pressure PID immediately
- Check if relief valve has opened
- Inspect high-pressure lines for leaks
- Test pressure regulator operation
- Review PCM fuel pressure command
Repair notes
SAFETY ISSUE - high-pressure fuel leak risk. Replace pressure regulator or relief valve. Inspect all high-pressure fittings for damage or weeping.
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