Happytown

This thread was very helpful, wanted to contribute something back: Spoiler: replaced Fuse 74 TIM, fixed our issues. 2019 Sierra SLT X31 Texas Edition, just bought it used about a week ago. First time towing our small utility trailer, had trailer lights when we left home Friday. Two days later (today), no trailer lights at all. Even with no trailer connected, the monitoring system was showing trailer connected, and flagging an issue with Left and Right turn lights. Also at this time, the truck turn signals were "fast blinking" like an old school flasher going bad. We left the trailer at the camp and got on the road. This is when we also noticed the Fuel "distance to empty" was not updating, just frozen at like 283 miles even after driving 20 miles or so. Long story long, I head read this entire thread by the time we hit the Dairy Queen (I'm riding shotgun, its my sons truck) and I hopped out and pulled Fuse #74, sure nuff, busted. Replaced it with a spare and all symptoms resolved with the trailer monitoring system and fuel DTE updated immediately. Hope this helps someone else.