What causes a SPN 3473 code?

SPN 3473 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 3473 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3473 active.

How do I fix SPN 3473?

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 3473

Aftertreatment 1 Hydrocarbon Injector Stuck Open

What it means

The Engine Control Module detects that the aftertreatment fuel injector (7th injector) is leaking or stuck in the open position, causing unplanned fuel delivery into the exhaust stream.