What causes a SPN 906 code?

SPN 906 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 906 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 906 active.

How do I fix SPN 906?

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 906

J1939 SPN 906 — Engine Management parameter

What it means

SPN 906 indicates a 'Fitting Error' or 'Parameter Mismatch' within the Engine Management system. It typically means the ECM has detected a configuration setting that does not match the hardware or the expected operating map.