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.

Real-world scan data

Seen in

1,135

scans in the past year

Found in

0.2%

of scans

0.3%

of scans that found faults

Appears alongside · share of P0251 scans

P0401in 46.0% of scans

P0402in 41.5% of scans

P0704in 37.4% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

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.

Read & clear P0251 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX