OBD-II · Engine and powertrain (P)
P0251
Injection pump fuel metering control A fault
What it means
The engine computer detects a fault in the fuel metering control. On common-rail diesels this is usually the fuel metering (volume control) valve on the high-pressure pump, which sets how much fuel the pump pressurises.
Symptoms
- loss of power or limp mode
- hard starting or stalling
- engine warning light
Likely causes, most likely first
| No. | Cause |
|---|---|
| 01 | fuel metering valve sticking or failed |
| 02 | contaminated diesel (water, dirt) |
| 03 | worn high-pressure pump |
| 04 | rail pressure sensor fault |
| 05 | wiring fault |
What to check, step by step
- 01Compare requested and actual rail pressure and metering valve current in live data.
- 02Inspect the metering valve connector and wiring.
- 03Check fuel for water or contamination; change the filter.
- 04Replace the metering valve if faulty (on some pumps only the whole pump is sold).