I just put a new/rebuilt tranny in my 94 f-250. The tranny went into limp-mode on test drive as soon as the truck got up to temp. With the key on I'm getting a buzzing noise from the solenoid pack in the tranny. The only tranny code i get with KOEO is for the TOT sensor which I'm assuming was from the heat build up during the test drive after it went into limp-mode and code 55 which is low voltage to PCM pin #5. I did not have any shifting problems with the old tranny.

 

If the old one shifted good why did you replace it?

Go ahead and post up all of your codes. Did the tests run to completion?

I have never heard any electrical noise from my transmission.

Call the transmission builder. Who built it?

 

Replace your PCM relay (for IDI diesel trucks,TECA relay). When the solenoids "buzz" the relay is bad.