What causes a SPN 965 code?

SPN 965 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 965 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 965 active.

How do I fix SPN 965?

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 965

J1939 SPN 965 — Engine Management parameter

What it means

SPN 965 typically refers to the Fan Drive State or Engine Cooling Fan Clutch Control circuit. It indicates an electrical discontinuity or irrational signal in the fan control circuit.