OBD-II Code P0250 — What It Means & How to Fix It

What Does This Error Mean?

P0250 means there's a fault in the fuel metering unit on your injection pump. This part controls exactly how much fuel gets delivered to your engine. It's most common on diesel vehicles with high-pressure fuel injection systems. Your engine may run rough, lose power, or struggle to start. Left unfixed, poor fueling can damage your engine over time.

Affected Models

All diesel vehicles 1996+
Common in Ford F-250/F-350 Power Stroke
Common in GM Duramax diesels
Common in Dodge Ram Cummins
Common in VW TDI models

Common Causes

Failed or sticking fuel metering unit inside the injection pump
Low fuel pressure caused by a clogged fuel filter or weak lift pump
Wiring harness damage or corroded connector at the metering unit
Contaminated diesel fuel with water or debris affecting the pump
Internal injection pump wear causing pressure regulation problems

How to Fix It

Start by replacing the fuel filter. A clogged filter starves the injection pump and can trigger this code. Use the filter specified for your vehicle and diesel engine type.

Diesel fuel filters should typically be replaced every 15,000–30,000 miles. Many owners skip this.
Inspect the wiring and connector going to the fuel metering unit. Look for frayed wires, burnt insulation, or green corrosion on the connector pins. Clean or repair as needed.

Spray electrical contact cleaner on the connector, reconnect firmly, and re-scan for codes.
Check your fuel for water contamination. Many diesel systems have a fuel-water separator — drain it if it shows water. Bad or old diesel fuel can also cause pump issues.

Water in diesel fuel is a common culprit, especially in humid climates or after sitting unused.
Test fuel pressure at the injection pump inlet. Low pressure means the lift pump or supply lines are the issue, not the metering unit itself. A diesel technician can do this properly.

Fuel pressure specs vary by engine — consult your service manual for the correct values.
If all of the above check out, the metering unit or injection pump itself may need replacement. Have a diesel specialist inspect the pump with appropriate diagnostic software.

Some pumps can be rebuilt at a fraction of the replacement cost. Ask your shop about that option.

When to Call a Professional

Diesel injection pump work is highly specialized — not a DIY job for most people. If replacing the fuel filter and checking wiring doesn't clear the code, take it to a diesel shop. Injection pump replacement or rebuild can cost $800–$2,500 depending on the vehicle. Get a diesel specialist, not just any mechanic — this system requires specific tools and knowledge.

Frequently Asked Questions

Can I drive with a P0250 code?

Short trips are usually okay, but you should not ignore this code. Poor fuel metering can starve cylinders, causing rough running and long-term engine wear. If the engine is misfiring, losing significant power, or producing black smoke, stop driving and get it checked immediately.

Is P0250 only a diesel problem?

Mostly yes. P0250 is almost exclusively seen on diesel vehicles with injection pump systems. Gasoline engines use a different fuel delivery design and rarely trigger this specific code. If you see it on a gas vehicle, check for wiring issues or an ECM fault first.

How much does it cost to fix P0250?

If it's just a fuel filter, expect $50–$150 in parts and labor. Wiring repairs typically run $100–$300. If the injection pump needs replacement, budget $800–$2,500 depending on your engine. A diesel rebuild shop may be able to repair the pump for less — ask before replacing.