What causes a SPN 3301 code?

SPN 3301 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 3301 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3301 active.

How do I fix SPN 3301?

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 3301

SPN 3301 Aftertreatment SCR Intake Temp High

What it means

This fault indicates that the Selective Catalytic Reduction (SCR) intake temperature has exceeded the maximum operating threshold allowed by the ECM.