I just took my first trip to the mountains with my 05 48RE and the 10,000# gooseneck enclosed trailer. While on the interstate everything was fine, and the truck ran great, when I got into the mountains on a 2 lane road, we ended up in 2nd gear, and the hot trans light came on. What temp does this light come on at, and what should I do to fix this. It seemed that the torque converter was not locked up, even though I was in tow/haul. Any ideas???