P0003 code meaning
Fuel Volume Regulator A Control Circuit Low
Powertrain system Generic code P00xx codes Check engine light
What P0003 means
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.
P0003 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P0003
- Check engine light on
- Hard starting or stalling
- Loss of power or limp mode
- Low rail pressure code possible
Common causes of P0003
- Most likelyHarness chafed through, short to ground
- PossibleShorted turns in the regulator coil (resistance too low)
- PossibleWater or corrosion in the connector
- Less likelyOutput driver in the engine control module faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel volume regulatorHigh pressure fuel pumpFuel volume regulator wiring
What each part of P0003 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 0 | Area: fuel and air metering and auxiliary emission controls. |
| 03 | The exact fault in that area. |
What to do next
- Note P0003 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0003
What does P0003 mean?
P0003 means "Fuel Volume Regulator A Control Circuit Low". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P0003?
Drive gently and only to a workshop. With P0003 the car can go into limp mode (reduced power) to protect itself.
Will P0003 fail an emissions test?
Yes, it can. P0003 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0003 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0003 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.