Reverse issues bmw x5

[poppy400_0]

Coming from work the other day i stop a the supermarket to pick some things up got back into the Xs and to my surprise she wouldn't reverse but drive is ok i didn't get any warnings from the Xs no check engine soon I was able to park in front of my drive way so i could pull out the next day for work Well went to work the next day , on break i sat in the X Started her up to get warm because its a little cold in NYC i decided to put the X IN REVERSE and she reverse i have not a clue to whats going on i checked the trans fluids everything is good . a friend told me it could be the Tcc solenoid .I need help !!!!