P0003Fuel Volume Regulator A Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- The fuel volume regulator (also called metering unit or suction control valve) is a solenoid valve on the inlet side of the high-pressure pump, used mainly on common-rail diesel engines. The engine control module pulses it to set how much fuel the pump draws in and delivers to the rail, and in this way controls rail pressure. P0003 means the control module measures a voltage or current below the expected range on the control circuit, typically because of a short to ground. On some output stages an open circuit is also reported as low. A short on the switched ground side can keep the valve permanently energised.
- What you may notice
- Check engine light on
- Hard starting or stalling
- Loss of power or limp mode
- Low rail pressure code possible
- Likely causes
- LikelyHarness chafed through, short to ground
- PossibleShorted turns in the regulator coil (resistance too low)
- PossibleWater or corrosion in the connector
- RareOutput driver in the engine control module faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €80 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.