P0257
Injection Pump Fuel Metering Control "B" Range/Performance (Cam/Rotor/Injector)
- Severity
- High
- Driving
- Drive only to a garage
Injection pump fuel metering control "B" is responding, but the amount of fuel delivered does not match what was commanded. That points at the pump, the fuel supply feeding it, or wear - the circuit itself is not being blamed.
Possible causes
- CommonFailed fuel metering control solenoid or valve
- CommonWiring or connector fault at the injection pump
- CommonWorn injection pump
- CommonLow fuel pressure, a blocked filter, or air in the fuel system
- PossibleContaminated or misfuelled diesel
- RareFailed control module driver
What you might notice
- Reduced power or limp mode
- Excessive smoke
- Hard starting or no start
- Rough running
- Engine cutting out
- Check engine light on
What to check, in order
- Check the fuel filter and when it was last changed. A blocked filter starves the pump and produces metering faults with a perfectly good pump - and it is by far the cheapest thing to eliminate.
- Check the connector and wiring at the injection pump.
- Look for air in the fuel system, and for leaks on the suction side that would let it in.
- Ask about recent fuelling. Contaminated or misfuelled diesel damages high-pressure pumps, and the damage spreads to the injectors.
- Get a professional assessment before replacing the pump - it is one of the most expensive parts on a diesel and it is often blamed for supply problems upstream of it.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Fuel and air metering - injector circuits
P0200P0201P0202P0203P0204P0205P0206P0207P0208P0209P0210P0211P0212P0213P0214P0215P0216P0217P0218P0219P0220P0221P0222P0223P0224P0225P0226P0227P0228P0229P0230P0231P0232P0233P0234P0235P0236P0237P0238P0239P0240P0241P0242P0243P0244P0245P0246P0247P0248P0249P0250P0251P0252P0253P0254P0255P0256P0257P0258P0259P0260P0261P0262P0263P0264P0265P0266P0267P0268P0269P0270P0271P0272P0273P0274P0275P0276P0277P0278P0279P0280P0281P0282P0283P0284P0285P0286P0287P0288P0289P0290P0291P0292P0293P0294P0295P0296P0297P0298P0299