What causes a SPN 964 code?

SPN 964 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 964 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 964 active.

How do I fix SPN 964?

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 964

J1939 SPN 964 — Engine Management parameter

What it means

Transmission Requested Torque Control Strategy. This code indicates the engine controller is not receiving or cannot process the transmission's request to limit torque during shifts.