P0001Powertrain
Powertrain · SAE
Fuel Volume Regulator Control Circuit Open
Meaning
The fuel volume control valve (FCV/MPROP) on the high-pressure common-rail pump receives no command signal from the ECM. The control circuit is open.
Common causes
- Broken wiring or disconnected connector at the FCV valve
- Faulty FCV valve (open-circuit coil)
- Blown fuse or pump supply relay
- Short circuit in ECM-side wiring
- Faulty ECM (rare)
Symptoms
- Check-engine light (MIL) on
- Hard start or no-start
- Unregulated common-rail pressure
- Black smoke or power loss
- Limp-home mode active
Severity
High: uncontrolled rail pressure can damage injectors and the pump; repair immediately.
What to do
- Check supply voltage and ground at the FCV connector
- Measure FCV coil resistance against manufacturer specification
- Inspect wiring between ECM and valve for breaks or corrosion
- Replace the FCV if the coil is out of specification
- Investigate the ECM only after ruling out all external causes