Was towing our camper over the weekend. Always tow in tow/haul mode. Going down a hill, heard a small bang and started to accelerate. The dash flash' "transmission modes unavailable", then service advance trac, then hill start assist fail. Check engine light never came on though. My cruise control was also non responsive after this. Took it to a dealer after we got to the campground. Found out there is TSB for '18 & -'19 F-150s made in the Dearborne plant that can exhibit this problem. The tech updated the software and then went through some calibration on the abs sensor. Codes cleared, and everything reset. Had no issues on the return trip. Got up to about 11mpg on the way back.

 

Great they fixed it! Would you have that TSB number? It should be on the worksheet,

 

They didn't even write up a work order. The tech just showed me the TSB that popped up on his diagnostic computer. You're right, though, I should have written it down.