Towing issues and questions

Been a while since I’ve been on.
Got back to Western NC yesterday from towing my 14’ V nose, dual axle enclosed trailer with 2 Harley dressers (about 4500lbs total with gear and luggage) from Colorado and I had an issue that I’m hoping can get some help with. Trailer has brakes and towing with a 2017 CrewMax 5.7
When we got outside of Denver, I was getting off the interstate and hit a massive bridge transition in the road and that’s when things went haywire. I immediately got the info message that said wiring, connector, problem or something of the sort. I’m sure you’ve seen it before. I pulled over, shut off the truck and disconnected the trailer wire and reconnected. The message went away and made it to my destination.
When we left Saturday, the message came back so I turned the truck off and back on. As soon as I touched the brakes, the message came back on. It felt like the brakes were engaging so we continued on the road.
When we were getting off the interstate for fuel, I kept hearing the IBC clicking. This happened repeatedly every time we stopped. In addition, the manual gain stopped working completely.
with that said, is the IBC done and needs to be replaced? If so, I plan on using the Prodigy P3 and harness.

Second question is this…..
Does anyone who tows regularly have a SC and if so, what are your thoughts? Fuel mileage while towing?
The truck pulls good but only getting 11.3 average and then downshifting from S5 to 4 every time we went up a hill got really old, really quick. Not only that but with not using CC, I felt I had to really keep the pedal down the entire trip. And 1200 miles each way made the drive not fun.
Any help and advise on the two questions would be greatly appreciated
Thanks in advance fellas
Mike

 

Your second question is just a fact of life when towing with a gas engine.

 

Sound alike that bridge transition jarred something. Could be the trailer and not the truck. As far as your towing experience, if you were towing 4500#, the manual suggests tow haul mode and S4 gear selection. What was your average speed? I’m sure a trip that far your trying to keep it at 70mph or more which is also not recommended. That new turbo engine or a diesel would fare better at this task. But the supercharger sounds like more fun!!