P0001 — Fuel Volume Regulator A Control Circuit/Open
The ECU detects an open circuit in the control of fuel volume regulator A (often the metering valve on the high-pressure fuel pump). The actuator does not respond, so rail pressure cannot be controlled accurately.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Fuel volume regulator
- High pressure fuel pump
- Fvr wiring
- Fvr connector
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Wiring break or unplugged connector
- Regulator solenoid coil open
- ECU output driver failed
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- Reduced-power or limp mode may occur
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
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.