What causes a SPN 455 code?

SPN 455 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 455 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 455 active.

How do I fix SPN 455?

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 455

J1939 SPN 455 — Fuel/Air parameter

What it means

SPN 455 is a general J1939 fault indicating a deviation or rationality error in the Fuel/Air parameter, meaning the engine control module detects that the ratio of fuel being injected does not match the air mass entering the cylinders.