Shift from 2H/4L to 4H, Module Chatter/Clicking Noises-No Shift

Electronic Shift Transfer Case Schematic:

Shift From 2H to 4H Results in Chatter and Clicking Noises from the Module, But NO Shift
Typically, in this situation the Motor hunts for 4H, but overshoots, then hunts back and overshoots the other way. After 7-10 seconds, the Module returns to the default, which is 2H. This problem is normally not the sensor input. It is usually the result of the Motor running too fast or braking too slowly to allow the Module to position it accurately. The motor must be replaced.