What causes a SPN 878 code?

SPN 878 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 878 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 878 active.

How do I fix SPN 878?

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 878

J1939 SPN 878 — Engine Management parameter

What it means

Indicates an error or inconsistency in the Engine Management Parameters within the Electronic Control Unit (ECU). This is usually a software or configuration fault rather than a physical circuit failure.