What causes a P0257 code?

P0257 can be triggered by several issues — see the verified probable causes and step-by-step diagnostics shared by mechanics and owners on OBDIY.

Can I drive with a P0257 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P0257 active.

Follow the step-by-step diagnostic on this page, then read the verified fixes contributed by other Heavy Truck owners — the answer marked "Verified Cause" worked for the original poster.

OBDIY

OBD-II

P0257

Injection Pump Fuel Metering Control B Range Fault

What it means

The Engine Control Module (ECM) has detected an out-of-range signal or performance issue with the secondary high-pressure fuel pump metering unit circuit.