What causes a SPN 923 code?

SPN 923 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 923 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 923 active.

How do I fix SPN 923?

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 923

J1939 SPN 923 — Engine Management parameter

What it means

SPN 923 is a J1939 network parameter related to the Engine Management System's identification or configuration data. It usually indicates a data mismatch or missing message rather than a mechanical failure.