Measured fuel pressure is below the target. The driver may notice weak power, hesitation under load or a hard start.
Likely causes, most common first
- Clogged fuel filter
- Weak fuel pump
- Faulty pressure regulator or high pressure pump
- Faulty fuel pressure sensor
Parts usually involved
- Fuel filter
- Fuel pump
- High pressure pump
- Fuel pressure sensor
Test before you replace
Compare actual and target pressure live under load and confirm with a mechanical gauge where possible.
General guidance for generic OBD2 codes. Always follow the maker's procedure for the car in front of you.