What causes a SPN 3490 code?

SPN 3490 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 3490 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3490 active.

How do I fix SPN 3490?

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 3490

SPN 3490 — Aftertreatment 1 Purge Air Actuator

What it means

SPN 3490 refers to the Aftertreatment Purge Air Actuator. This component is responsible for clearing out excess diesel fuel or DEF from the dosing lines/nozzle using compressed air to prevent clogging and crystallization.