What causes a SPN 3790 code?

SPN 3790 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 3790 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3790 active.

How do I fix SPN 3790?

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.

J1939 SPN

SPN 3790

J1939 SPN 3790 — Body/Chassis parameter

What it means

DPF Regeneration Inhibit Switch Status or general Body/Chassis parameter communication mismatch. This code signifies that the engine controller is receiving invalid data or is failing to receive a message from the body controller regarding chassis-related parameters (often related to DPF inhibit or PTO status).