What causes a SPN 996 code?

SPN 996 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 996 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 996 active.

How do I fix SPN 996?

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 996

J1939 SPN 996 — Engine Management parameter

What it means

SPN 996 indicates an issue with the Engine Management parameters on the J1939 network, typically relating to engine protection features such as low oil pressure or high coolant temperature overrides.