What causes a SPN 499 code?

SPN 499 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 499 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 499 active.

How do I fix SPN 499?

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 499

J1939 SPN 499 — Fuel/Air parameter

What it means

SPN 499 is a general J1939 network parameter code indicating that specific fuel or air data is missing, invalid, or not being received by a monitoring module.