For the past month I have been dealing with an issue where, at higher speeds, ie above 70mph, my 6 speed automatic 2015 Cooper pulls out of gear and will not reengage until the car is shutoff and left off for 5-10 minutes, after which the car engages gear but feels like it is slipping when power is applied. After slipping, the transmission will make a faint grinding noise like it is trying to reengage but can’t. Once it does go back in gear if it is pushed beyond 50 mph it will slip out again.

However, if the trip stays below the 70+ region the car works fine with solid gear engagement.

I checked trouble codes with BimmerLink and there are no transmission faults but the transmission control module is not coded to the car, although, it has been like that since I bought the car four years ago. Transmission fluid has been changed and fluid color was good with no metallic particles suspended in the fluid.

If anyone has an idea of what may be wrong or what has to be replaced please let me know.