Fuel and air

P0003 — Fuel Volume Regulator Control Circuit Low

Severity: medium Drive with care, to a shop

What P0003 means

The fuel volume regulator (control valve) meters how much fuel reaches the high-pressure pump, which helps hold the correct fuel pressure. P0003 sets when the control module sees too low a voltage or signal in that regulator's control circuit. Typical triggers are an open circuit, a short to ground or a failing regulator.

Symptoms

  • Check Engine Light on
  • Reduced power and sluggish acceleration
  • Limp mode
  • Hard starting or long cranking
  • Stalling or cutting out
  • Rough or unstable idle

Possible causes

  1. Failed fuel volume regulator or its solenoid
  2. Damaged wiring harness or corroded connector
  3. Control wire shorted to ground
  4. Poor ground or blown fuse in the regulator circuit
  5. Weak low-pressure supply (lift pump, clogged filter)
  6. Faulty PCM (rare)

How to diagnose

  1. Scan all codes and freeze-frame data, clear the code and see if it returns
  2. Inspect the regulator wiring and connector for chafing, moisture and corrosion
  3. Check the fuse and power supply to the regulator circuit
  4. Measure solenoid resistance with a multimeter and compare to spec
  5. Test the control wire for a short to ground or an open to the PCM
  6. Check low-pressure fuel supply pressure and volume
  7. Compare specified and actual rail pressure at cranking, idle and under load with a scan tool
  8. Command the regulator with a scan tool, if supported, to confirm it responds

Common fixes

  • Repair the wiring open or short and clean or replace the connector
  • Replace the fuel volume regulator or solenoid
  • Replace the fuse and restore a good ground
  • Fix the lift pump or replace the fuel filter if supply is weak
  • Reprogram or replace the PCM only if everything else checks out

Questions and answers

What does P0003 mean?

The PCM detected a low signal in the fuel volume regulator control circuit. The regulator itself or its wiring is the most common culprit.

Can I drive with P0003?

Only briefly and carefully, to get to a shop. The engine may lose power, stall or be hard to start, so don't wait long.

What should I check first for P0003?

Start with the regulator connector and wiring, the fuse and ground, then solenoid resistance and low-pressure fuel supply.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.