Fuel Rail/System Pressure Too Low
The ECU detects fuel rail pressure below the desired setpoint despite maximum pump and metering valve commands. Common in direct injection diesel and gasoline systems where high-pressure pump or rail pressure regulator fails.
Affected components
- High pressure fuel pump
- Fuel pressure regulator
- Fuel rail
- Fuel filter
- Fuel injector
Common causes
- High likelihood: High-pressure fuel pump worn
- Medium likelihood: Pressure regulator stuck open
- Medium likelihood: Fuel filter clogged
- Low likelihood: Injector leaking back
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
- Reduced-power or limp mode may occur
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.