Mustang Electronic Fiut Transmission Problem

Very good afternoon friends I hope you can help me in my big problem is sig. I have a Mustang 2000 3.8 Automatic LT with the elctronic fiut is the following when I get to 45 mph I release the change of rest is to have this way all the way enters and the change comes out and in the climb it is forced and only the obdrive enters without activating it when it turns it on the first thing I see is that OD/ OFF SIEMP There are three sensors and the three mentions me Abiero or in circuit I want to know if my problem will be a short circuit in the wiring or my computer is bad and if there is any manual to check it myself I hope I could help me already put everything new to my transmission including the turbine. Friends help you thank you very much