I was driving on the highway this afternoon for about 20 minutes at 75mph with the cruise control on. I slowed down to about 65mph until I could change lanes to get around a slower vehicle. When I started hitting the + button to put the cruise back to 75mph, the transmission shifted from 10th to 9th gear, then banged hard into 7th gear, sat there at about 4000rpm for a couple seconds with no acceleration, then showed it shifted into 1st gear, then to 9th gear where it slowly picked up speed again. I tried the same speed change again two more times with the same result and the last time the transmission actually got stuck in 9th gear and wouldn’t budge even in manual mode. I shifted to neutral and pulled off to the side of an exit ramp. I put the truck in park for ~30 seconds and then back into drive and it showed it was in 5th gear despite being stopped. After a key cycle it seemed to go back to normal again. Anyone else ever run into this behavior?

 

Never that behavior, but I would be in touch with the Dealer. Sounds like some electronics misbehaving, hopefully through a code they can detect.