Fuel Pressure Regulator 1 Performance
On direct injection engines (common rail diesels and many petrol engines), fuel reaches the injectors at very high pressure from a shared pipe, the rail. A sensor measures that pressure and a regulator adjusts it. This code means the regulator cannot achieve the pressure the engine computer requests.
What the car has detected
The engine computer compares the pressure it commands with the one it measures and has seen a difference, or a correction, larger than allowed.
You can drive carefully, but the engine may run unevenly or lose power. Get it checked soon.
Symptoms
- Engine warning light on
- Uneven running or hesitation
- Loss of power
- Hard starting
Possible causes
- Rail pressure sensor reading off or failing intermittently
- Pressure regulator or its circuit with excessive resistance
- Leaking or restricted injector
- Short circuits in nearby circuits (crankshaft sensor or camshaft actuator)
Checks for the garage
- Read the other codes (for example pump timing ones) and the freeze frame data
- Compare actual and requested rail pressure in live data, at idle and when accelerating
- Command the pressure up and down with diagnostics and see whether the sensor follows
- Check power, earth and wiring of the regulator and the pressure sensor
- Test the injectors if the circuit and sensor are fine
Next step
Have the rail pressure sensor, the regulator and its circuit, and the injectors checked.
Go to a garage if the code comes back or if the engine runs unevenly. Diagnosing the regulator and sensor needs equipment.