P0251
Injection Pump Fuel Metering Control A (Cam/Rotor/Injector)
Fuel injection (diesel)
Generic OBD-II
High
What it means
P0251 means the ECM has detected a problem with the "A" fuel-metering control in the diesel injection pump — the mechanism that meters how much fuel is delivered. When it can't control fuel accurately, the engine may start hard or not at all, stall, run rough, and lose power. Fuel supply and wiring are worth checking before condemning the pump.
High
Can I keep driving? Risky — poor fuel metering can cause hard starting, stalling, or major power loss, so get it serviced before relying on the vehicle.
Common symptoms
What you'll notice
- Check-engine light on
- Hard starting or a no-start
- Rough running or stalling
- Reduced power and poor acceleration
- Surging or excess smoke (diesel)
Common causes
Most likely first
- Faulty fuel-metering control valve or an internal injection-pump faultLikely
- Wiring or connector fault at the metering-control solenoidCommon
- Low fuel-supply pressure, restricted fuel filter, or air in the fuelCommon
- Failed ECM or pump driver (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check fuel supply and the filter first.
- Inspect the metering-valve connector and wiring for damage or corrosion.
- Test the metering-control solenoid's resistance and operation.
- Check injection-pump pressure against the manufacturer's spec; overhaul or replace the pump if it has an internal fault.
- Clear the code and re-test.
FAQ
Quick answers
Is it safe to drive with P0251?+
Not really. Faulty fuel metering on a diesel can cause stalling, hard starting, and severe power loss, which can leave you stranded. Have it diagnosed before further driving.
Can I just clear P0251?+
It comes back until the pump, solenoid, or fuel-supply fault is repaired. Fix the cause rather than clearing it.
Related codes
Often seen with P0251
Read & clear P0251 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX