hi i am shannon i will help on this issue
when the transmission will not shift the computer has put it in to limp in mode.
you will need the have the computer scaned for codes first
this will give the tech a place to start
most likely you have a bad solenoid in the trans.
that is not a hard job to do
after testing the code if it is in the trans they will need to remove the oil pan to get to the solenoids
that takes two hours .one for the computer testing and the other to remove the pan almostany computer controlled part in the trans can be replaced fo less that 1 hour
then you will have the cost of the part the gasket and have the filter changed.
and some trans fluid . it could be less than $500.00 if no hard parts are broken in the transmission
i hope this answered your question please press the green ACCEPT button i will still answer on this issue thanks shannon.