What causes a SPN 3233 code?

SPN 3233 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 3233 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3233 active.

How do I fix SPN 3233?

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 3233

SPN 3233 Aftertreatment 1 SCR Intake Gas Temperature

What it means

This code triggers when the Selective Catalytic Reduction (SCR) intake gas temperature sensor detects data that is erratic, intermittent, or outside of the expected operating range.