What causes a SPN 425 code?

SPN 425 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 SPN 425 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 425 active.

How do I fix SPN 425?

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

J1939 SPN

SPN 425

J1939 SPN 425 — Fuel/Air parameter

What it means

Fuel Temperature Sensor circuit abnormal. The ECM detects a signal from the fuel temperature sensor that is outside of the calibrated range (too high or too low).