It is possible to fix this problem yourself and save $3000+ dollars from having the dealer replace and reprogram. But first you want to make sure its the transmission!!!
The video will only cost $10 but you could save $ hundreds and much grief by watching this video. This will help in dealing with fixing a limp-home mode problem.
On the 7-speed transmissions from 2003 to 2016 transmission fluid level has be checked from under the car, with the engine running and the correct temperature reached.