What causes a SPN 363 code?

SPN 363 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 363 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 363 active.

How do I fix SPN 363?

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 363

J1939 SPN 363 — Fuel/Air parameter

What it means

SPN 363 is a generic J1939 parameter indicating a deviation in the commanded versus actual fuel/air ratio. It signifies that the engine controller cannot maintain the stoichometric or desired combustion mixture.