My 17 started doing the very same 4 wks ago while I was pulling my trailer to the MX races 2hrs away. I ended up turning around halfway there and nursing it home. It's been back 2 times since with the same problem and I'm beginning to lose faith in my dealer. They put a module and a valve body in it this week and they tested it with my trailer attached for over an hr on the highway and it didn't get hot or have any issues. I got back but I drove it for less than 50 miles before we left for vacation with our motorhome. I'd swear something is still wrong with it because you know how you know your truck and it feels to me like the tranny is thinking about what gear it wants to be in because it's jumping around quite a bit. It's not shifting hard or anything like that but it just doesn't feel right. I'm going to look into it more when we get home on Monday.
My 18 does the same between 2-5. It holds and the jumps 2-3 gears. No matter how soft I push the pedal. Nothing major but it got to a point that I thought it was normal. Hoping to stay clear from anything major