P0002
Fuel Volume Regulator A Control Circuit Range/Performance
The control signal of fuel volume regulator A is electrically present but the actual rail pressure does not follow the target value within tolerance. Indicates a mechanical or hydraulic issue rather than pure wiring.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- High-pressure pump worn or leaking internallyCommon
- Regulator valve sticking from contaminationPossible
- Rail pressure sensor reading driftedPossible
Parts involved
- Fuel Volume Regulator
- High Pressure Fuel Pump
- Fuel Rail Pressure Sensor
P0002 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.