P0001: Fuel Volume Regulator A Control Circuit/Open
Do not keep driving
Expect poor starting or a severe loss of power. This is not a code to drive on; the fuelling system is running without proper pressure control.
What this code means
The control module commands the fuel volume regulator — the valve that decides how much fuel the high-pressure pump actually delivers — and has detected an open circuit in that command line. This is direct-injection and diesel territory, where rail pressure is regulated at the pump rather than by a return line. With the circuit open the regulator usually defaults to a fail-safe position, which is why the symptom is often a no-start or a hard limp rather than a subtle running fault.
Likely causes
Start here
- Open or broken wiring to fuel volume regulator · moderate
- Corroded or loose connector · easy
- Failed fuel volume regulator · moderate
Less common
Rare
- Control module driver failure · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about P0001.