Fuel and air

P0256 Injection pump fuel metering control: circuit fault ("B")

By: Diagno editorial team · Updated: 2026-10-15

P0256 means: Injection pump fuel metering control: circuit fault ("B"). The computer monitors fuel pressure in the system. Drive gently and have the car checked soon. The repair usually costs about €60–300 in Estonia. The most common cause: connector loose, damp or corroded. Other possible causes: wire broken or chafed, faulty sensor or regulator.

Is it safe to drive?Get it checked soonDrive gently and have the car checked soon.

Typical repair cost€60–300parts and labour in Estonia

What it means

The computer monitors fuel pressure in the system. The pressure is wrong, the regulator isn't working, or the pressure sensor reading isn't plausible. The computer found a fault in the electrical circuit: the part, a wire, a connector or a fuse.

What you may notice

Engine light on
Hard starting
Less power or limp mode
The engine may stall

What could be wrong

1Connector loose, damp or corroded
2Wire broken or chafed
3Faulty sensor or regulator
4Engine computer fault (rare)

Repair difficulty: Moderate

What you can check yourself

First look at the connector and wiring: anything loose, melted or green with corrosion? If the fuel filter hasn't been changed for a long time, start there. Check for any fuel leak or smell. Best left to a workshop. It needs a diagnostic tool and experience.

How we fix it

We read the fault data on the diagnostic tool and check whether the fault is constant
We measure the circuit's supply, ground and signal
We repair the wire or replace the connector
If the wiring is fine, we replace the sensor or regulator

Standard SAE description: Injection Pump Fuel Metering Control B Malfunction (Cam/Rotor/Injector)

This code usually comes with: Check engine lightSee what the light means →

Related symptoms: Car won't start · Loss of power or limp mode

Want a definite answer?

Bring the car to our workshop in Estonia for diagnostics. We read the fault codes, test the sensors and tell you what is wrong. Repair price depends on the work involved, generally €45 per hour.

Book a diagnostic check

Questions

What does fault code P0256 mean?

Injection pump fuel metering control: circuit fault ("B"). The computer monitors fuel pressure in the system. The pressure is wrong, the regulator isn't working, or the pressure sensor reading isn't plausible. The computer found a fault in the electrical circuit: the part, a wire, a connector or a fuse.

Can I drive with code P0256?

Drive gently and have the car checked soon.

How much does it cost to fix P0256?

Roughly €60–300 in Estonia. The price depends on exactly what has failed and on the car.

How is P0256 fixed?

We read the fault data on the diagnostic tool and check whether the fault is constant. We measure the circuit's supply, ground and signal. We repair the wire or replace the connector. If the wiring is fine, we replace the sensor or regulator.

Based on AI combined with our hands-on workshop experience and knowledge. This information is general and prices are approximate (Estonian workshop rates). The same code can mean different things on different cars. Only an inspection of the car gives a definite answer.