P0255
Injection Pump Fuel Metering Control A Intermittent (Cam/Rotor/Injector)
Fuel injection (diesel)
Generic OBD-II
High
What it means
P0255 means the ECM sees an intermittent fault in the "A" fuel-metering control of the diesel injection pump — the valve that regulates how much fuel the pump delivers. Because that control drops in and out, the engine can run rough, lose power, stall, or become hard to start. Loose wiring and a failing metering valve are common causes; the pump itself is checked last.
High
Can I keep driving? Drive with caution — an intermittent metering-control fault can cause sudden stalling, hard starting, or reduced power. Diagnose it before long trips.
Common symptoms
What you'll notice
- Check-engine light on
- Hard starting or intermittent no-start
- Rough running or stalling
- Reduced power and hesitation
Common causes
Most likely first
- Loose, corroded, or intermittent wiring/connector at the fuel metering control (circuit 'A')Likely
- Faulty fuel metering control valve/actuator on the injection pumpCommon
- Worn or failing injection pumpCommon
- Failed engine control module (ECM)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data, then wiggle-test the metering-control wiring and connector while watching for signal dropouts.
- Inspect and reseat the connector; clean corrosion and repair damaged wiring.
- Test the fuel metering control valve/actuator resistance and command it with a scan tool.
- Check injection-pump fuel pressure/delivery against spec.
- Replace the metering control valve or injection pump only after wiring checks out; suspect the ECM last.
FAQ
Quick answers
Is it safe to drive with P0255?+
Not for long trips — the fault is intermittent and can cause stalling or a no-restart. Get it diagnosed before relying on the vehicle.
Can I just clear P0255?+
It clears, but an intermittent metering-control fault returns once the loose wiring or failing valve acts up again. Fix the cause.
Related codes
Often seen with P0255
Read & clear P0255 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