if you have sideshift try swapping that circuit with the tilt, just move the SS plug on the lever pod to the tilt and see if problem goes away or moves to the SS function.
This will verify if the lever pod is bad or if the input unit or harness is bad.
Can't find anything in the service info about calibrating the joysticks so they may be self calibrating, i'll do some more looking and if i find anything i will post it back here.

make sure the connector sockets are clean , dirt can get in them and cause bad connections that can trigger this code.