P0001 — Fuel Volume Regulator Control Circuit/Open
Moderate severityWhat it means
P0001 is stored when the engine control unit sees a fault involving the fuel volume regulator control circuit. The fuel volume regulator controls how much fuel the high-pressure pump delivers to the rail, so faults here directly change fuel pressure. The “open” status means the control circuit is electrically broken — usually a cut wire, an unplugged connector or a failed driver.
Common symptoms
- The component does not respond to commands
- Hard starting or long cranking
- Power loss or limp mode under load
- Stalling in some cases
Likely causes
- Open or broken wire in the control circuit
- Unplugged or corroded connector
- Faulty fuel volume regulator
- High-pressure pump or pressure-sensor fault affecting the circuit
What to check first
- Check circuit continuity and connector pins with the key off
- Compare commanded vs actual fuel-rail pressure in live data
- Inspect the regulator connector and pump wiring
Can you keep driving?
Fuel-pressure faults can leave you stranded or trigger limp mode — diagnose it before relying on the car.
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