What causes a SPN 989 code?

SPN 989 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 989 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 989 active.

How do I fix SPN 989?

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 989

J1939 SPN 989 — Engine Management parameter

What it means

Engine Management Parameter (Parameter Identification Conflict/Error). This code indicates that the engine controller is receiving or transmitting a parameter value that is out of range, missing, or inconsistent with expected J1939 network data.