What causes a SPN 3248 code?

SPN 3248 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 3248 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3248 active.

How do I fix SPN 3248?

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 3248

Particulate Trap Regeneration Inhibit Switch Out of Range

What it means

Indicates the DPF regeneration inhibit switch signal is outside expected voltage range or reporting an invalid state to the ECM.