stepping motor issues

hey guys im working on a Samsung SE240 LC-3 excavator the stepping motor was replaced due to bad wires and the dial switch that controls it as well. the problem is the step motor will not reach max rpm and I have error codes ER14,ER22 but when I switch from auto to man and use the throttle cable it reaches the max rpm.
Ive checked for correct connection, fuses, grounds I cant seem to find where to check next any help will be awesome plus I don't have any schematic's for this piece of equipment

stepping motor issues