What causes a SPN 2801 code?

SPN 2801 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 2801 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 2801 active.

How do I fix SPN 2801?

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 2801

SPN 2801 FMI 7 - Engine Control Module Internal Hardware Failure

What it means

This fault code indicates a self-diagnostic failure within the Engine Control Module (ECM) related to internal memory, processing, or voltage regulation circuits.