What causes a SPN 1863 code?

SPN 1863 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 1863 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 1863 active.

How do I fix SPN 1863?

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 1863

Transmission Automatic/Manual Gear Shift Actuator Feedback Fault

What it means

This fault indicates that the transmission control module cannot verify the physical position of the gear shift actuator relative to the commanded position.