What causes a SPN 924 code?

SPN 924 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 924 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 924 active.

How do I fix SPN 924?

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 924

J1939 SPN 924 — Engine Management parameter

What it means

SPN 924 refers to the Engine Requested Speed Control. This is a networked parameter where the ECM receives a speed request from an external controller (like a PTO or cruise control) via the J1939 data link.