I was coming home yesterday from a week long camping trip. I was driving my 2004 Chevy 4500 pickup towing my 36' 5th wheel travel trailer. Driving 55MPH thru a congested area, everyone in front of me started locking up their brakes for no reason. I had to stand on the brakes, causing the truck to shake like crazy with the anti-lock system. As I got up to the rear of the car in front of me, the traffic started again. Really shook up wife and I. I drive another mile before taking a planned exit. As I did, I noticed the truck was not downshifting, Allison tranny, and the service transmission light was on. The transmission temp gauge was up to 180 to 190 degrees. I had never see it move before. I pulled off the side of road and wasn't sure what to do. I decided to turn off the engine and wait a minute or two. Then I started engine and the transmission service light did not come on and the tranny temp was falling like a rock. I put the truck in gear and everything was fine. I drove truck today and it performed like normal. Do I have a problem or did the panic stop just set a code in the tranny. Any suggestions? Thanks, John