What causes a SPN 3791 code?

SPN 3791 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 3791 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3791 active.

How do I fix SPN 3791?

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 3791

J1939 SPN 3791 — Body/Chassis parameter

What it means

J1939 Particulate Filter Active Regeneration Inhibit Switch signal received over the CAN network. This code usually indicates a configuration mismatch or an invalid status signal from the body/chassis controller regarding the DPF regen inhibit function.