P0003: Fuel Volume Regulator Control Circuit Low

What does P0003 mean?

The monitored fuel-volume regulator circuit measurement is below its expected limit. Low describes an electrical condition; the actual rail pressure must be read separately. This system is common on common-rail diesels and gasoline direct-injection engines; the exact regulator arrangement varies by engine.

Generic OBD-II definition: Fuel Volume Regulator Control Circuit Low. Confirm applicability in your vehicle service information.

Common causes

• Control wire shorted to ground
• Internally failed volume regulator
• Damaged connector or supply circuit

Symptoms

• Hard starting or no start
• Reduced power or limp mode
• Check engine light

Diagnostic focus

A low circuit reading does not prove low pump output. Compare this electrical code with P0087 or P0192 if those are present; each identifies a different part of fuel control.

Can I keep driving with P0003?

Severity: High Avoid driving if the engine stalls, leaks fuel, or runs roughly. High-pressure fuel testing belongs with a qualified technician; never loosen a fuel rail or injector pipe to check pressure.

If the check engine light is flashing or the car runs badly, stop driving and have it checked.

Typical fixes

• Inspect the regulator harness and plug
• Inspect for chafing to ground and check the regulator supply and control signals to the correct wiring diagram.
• Replace only the valve or wiring proven faulty

Sources & review

• OBD-Codes.com: P0003
• TroubleCodes.net: generic code definitions

Definitions and diagnostic background checked 2026-11-06. Generic guidance, not a substitute for the service procedure for your exact year, engine, and transmission.