Fuel Volume Regulator A Control Circuit Range/Performance
The control signal of fuel volume regulator A is electrically present but the actual rail pressure does not follow the target value within tolerance. Indicates a mechanical or hydraulic issue rather than pure wiring.
Affected components
- Fuel volume regulator
- High pressure fuel pump
- Fuel rail pressure sensor
Common causes
- High likelihood: High-pressure pump worn or leaking internally
- Medium likelihood: Regulator valve sticking from contamination
- Medium likelihood: Rail pressure sensor reading drifted
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.