P0256 — Injection Pump Fuel Metering Control "A" Intermittent (Cam/Rotor/Injector)
Drivable short-term, but fix now to avoid damage.
What P0256 means
This code means the engine computer detected an intermittent (on-and-off) fault in the 'A' fuel metering control circuit of the diesel injection pump. Intermittent codes are usually caused by loose or corroded connectors, chafed wiring, or a metering valve that's beginning to fail. Repairs focus on finding and fixing the unstable connection, often by inspecting and securing wiring and connectors before replacing parts.
Common symptoms
- Check engine light comes and goes
- Intermittent loss of power
- Occasional rough idle or hesitation
- Engine stumbling that comes and goes
- Hard starting at times
Common causes
- Loose or corroded electrical connector
- Chafed or intermittently shorting wiring
- Fuel metering valve beginning to fail
- Poor ground connection
- Vibration affecting a marginal connection
Typical repair cost
$120 – $1200
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0256 code?
You often can for a while, but the fault may become constant without warning and leave you stranded. It's best to get it checked before that happens.
How much does it cost to fix a P0256 code?
Because it's often a wiring or connector issue, repairs can be as low as $120, but can reach $1,200 or more if the metering valve or pump parts need replacing.
Is a P0256 code serious?
It can be. Even if symptoms are occasional now, intermittent fuel metering faults tend to get worse and can lead to stalling or a no-start. Don't put off diagnosis.
Why are intermittent codes like P0256 hard to diagnose?
Because the fault isn't always present, it can be tricky to catch during testing. Technicians often wiggle-test wiring and connectors while monitoring data to reproduce the glitch.