2011 E 70 "TRANSMISSION FAILURE" light

[Badasblkbmwx5]

I have had this issue happen 3 times in the past few weeks, leaving us stranded. Towed car to dealer and was told that the computer showing "TRANSMISSION MALFUNCTION" code. During the visit at the dealership for one week they we never able to duplicate the problem. That being said, the problem wasn't found and car was good to go! Picked up vehicle and drove straight home into garage. The very next morning same started fine, but would go into gear. Flat bedded again from inside garage. I'm in a loaner and informed the Service director not to call till they have "diagnosed" the problem. I have never abused this vehicle, completed all required servicing performed by the dealership??? Not really sure what to do but this is terrible as we drive the vehicle and a lot of times in rural areas with no cell phone service.