P0257 Code: Injection Pump Fuel Metering Control B Out of Range
🟠 Moderate severity · drivable
Drivable short-term, but the engine may run rough, lose power, or stall. Avoid long trips.
What P0257 means
The engine computer monitors a second fuel metering control (circuit B) inside the diesel injection pump. This code means the signal from that control is outside the expected range, so the pump may not be delivering the right amount of fuel.
Symptoms
- Check engine light is on
- Hard starting or long cranking
- Rough idle or stalling
- Loss of power while driving
- Poor fuel economy
Common causes
- most common: Faulty fuel metering component (circuit B) inside the injection pump
- common: Damaged wiring or a loose connector at the injection pump
- common: Worn or failing injection pump
- less common: Contaminated fuel or a clogged fuel filter
- rare: Engine computer fault
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Inspect and clean the injection pump connector | Yes | $0–20 |
| Repair damaged wiring to the injection pump | Mechanic | $50–200 |
| Replace the fuel filter if it is clogged | Yes | $20–60 |
| Replace or rebuild the injection pump | Mechanic | $1500–4000 |
Frequently asked questions
Can I drive with a P0257 code?
Yes for short trips, but the engine may run rough, lose power, or stall. If it stalls and won't restart, have it towed.
What is the most common cause of P0257?
A faulty fuel metering component inside the injection pump, or wiring and connector trouble at the pump.
How much does it cost to fix a P0257?
Simple wiring and connector repairs can cost under $200. If the injection pump needs replacing, expect $1,500 or more.
Related codes
P0256
P0256 Code: Injection Pump Fuel Metering Control B Malfunction
P0258P0258 Code: Injection Pump Fuel Metering Control B Signal Low
P0216P0216 Code: Injection Timing Control Circuit Malfunction
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.