P0255 Code: Injection Pump Fuel Metering Control A Signal Intermittent

🟠 Moderate severity · drivable

Drivable, but the signal can cut out, causing sudden rough running or stalling. Fix it soon.

What P0255 means

The engine computer monitors a fuel metering valve inside the diesel injection pump. This code means the signal from that valve drops in and out, so the pump delivers fuel unevenly. Intermittent codes usually point to a loose connection or damaged wiring.

Symptoms

Check engine light is on
Engine runs fine sometimes, then rough or stalls
Hard starting
Loss of power that comes and goes
Poor fuel economy

Common causes

most common: Loose or corroded connector at the injection pump
common: Damaged wiring with a broken wire or bad ground
common: Faulty fuel quantity adjuster inside the injection pump
less common: Water or contamination in the connector
rare: Engine computer fault

How to fix it

Fix	DIY?	Typical cost
Inspect, clean, and reseat the injection pump connector	Yes	$0–20
Repair the wiring or ground at the injection pump	Mechanic	$50–200
Replace or rebuild the injection pump if the adjuster is bad	Mechanic	$1500–4000

Frequently asked questions

Can I drive with a P0255 code?

Yes, but the engine may suddenly run rough or stall when the signal drops out. Drive carefully and fix it soon.

What is the most common cause of P0255?

A loose, corroded, or damaged connector and wiring at the injection pump. Intermittent codes are usually electrical connection problems.

Why does my P0255 code come and go?

Because the fault is intermittent — the metering signal works sometimes and drops out at other times, often when the vehicle hits bumps or the wiring moves.

Related codes

P0252

P0252 Code: Injection Pump Fuel Metering Control A Out of Range

P0253

P0253 Code: Injection Pump Fuel Metering Control A Signal Low

P0254

P0254 Code: Injection Pump Fuel Metering Control A Signal High

Updated 2026-08. This page is informational and not a substitute for professional diagnosis.