P0001 Fuel Volume Regulator Control Circuit/Open

P0001 indicates an open circuit in the fuel volume regulator control path. The powertrain controller cannot control the regulator circuit as expected.

Code details

Generic OBD-II · P0

System: Fuel / Air
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace the fuel pump or rail regulator before confirming the open control circuit and connector condition.

Symptoms of P0001

Check-engine light on, sometimes with rough or uneven running.
Hesitation, surging, or a noticeable change in fuel economy.
Occasionally hard starting or a smell of unburnt fuel.

Common causes of P0001

A failing or contaminated sensor (MAF, MAP, oxygen or air-fuel sensor).
Intake or vacuum leaks, or an exhaust leak near an upstream sensor.
Wiring, connector, or fuel-delivery problems that skew the reading.

Useful checks before replacing parts

Check fuel volume regulator power, ground or control command, connector fit, circuit continuity, and loaded voltage before replacing parts.
Inspect harness routing near the fuel pump, rail, or high-pressure pump, especially for rubbed insulation, corrosion, or loose terminals.
Compare fuel pressure command, actual pressure, regulator duty cycle, and freeze-frame load conditions to confirm the circuit fault.

Related OBD-II codes

These nearby fuel / air entries can help compare wording and pin down the fault area.