What causes a SPN 842 code?

SPN 842 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 842 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 842 active.

How do I fix SPN 842?

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 842

J1939 SPN 842 — Engine Management parameter

What it means

SPN 842 indicates a 'Parameter Programming Error' or 'Out of Range' error related to the Engine Management system. It signifies that the ECM has detected a configuration setting that is invalid, missing, or conflicts with other system parameters.