What causes a SPN 787 code?

SPN 787 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 787 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 787 active.

How do I fix SPN 787?

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 787

J1939 SPN 787 — Engine Management parameter

What it means

J1939 SPN 787 indicates a mismatch or error in the Engine Management Parameters stored within the Electronic Control Module (ECM). This usually refers to a 'Customer Parameter' configuration fault.