What causes a SPN 4347 code?

SPN 4347 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 4347 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 4347 active.

How do I fix SPN 4347?

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 4347

Cummins fault code 4347

What it means

Aftertreatment 1 SCR Intake Temperature - Root Cause Not Known. This indicates the SCR catalyst is unable to reach or maintain operational temperature, often due to physical obstruction or surface masking.