This has happened now twice while towing our camper. I get the error. "service advance trac" on the display on the dash. Then this last time it added the errors, "steering assist error" then it "hill stop assist deactivated". Once I unhook, there are no errors. I am assuming that it is all tied together. It is a 2017 3.5EB with 45,000 miles. I don't notice anything different with the truck while towing. It is going to the dealer as soon as they can get me in. Just wondering if anyone else has had these errors.

 

No idea, but please keep us posted what the Dealer finds. Good luck, hope it's under warranty, or at least is an inexpensive fix.

 

It did keep a code. The dealer found SSM47045 code. It is a battery monitor reset. There is actually a TSB for this error. The dealer I take it to had to call Ford because they had never encountered this error. Ford told the local dealer to do the reset and see if it happens again. If it does happen again there is a "series" of fixes. I will be towing the camper next week. Hopefully, this fixes it. If not, glad I have an extended warranty.
Side note. The Ford Pass app is great. It stored the error messages which helped the dealer get to the bottom of the problem. It was also nice to get a free Works Service for being an essential worker.

 

If your rear tires are squatting excessively with the trailer hooked up it will change the measured wheel speed for that axle and if the difference between that axle and the front wheels is large enough it can throw codes.

 

Following :

Mine also set messages last year while towing "hill assist", "forward collision" We'll see what happens this week when I finally get on the road again

 

It didn't do this last year or with the previous F-150. Apparently, it is happening to more than just mine if there is a TSB for it. I have a good weight distribution hitch and have it set to within 1/2" of unloaded. I will try airing up the rears before I go next time.

 

Have you tried turning off trailer sway control? Was this the first time you towed this trailer with this truck?

 

I guess I didn't know that could be turned off. I can try that. I assume that is in the menu options. I did tow with this truck last year and didn't have this issue. The only thing that has changed between last year and now is new tires. A responder said that if the tire compressed enough it would change the ratio from the front to the back and possibly throw a code. I will see if the reset from the Ford dealer does the trick. It must be the most correcting as it is the first step. Or it is the first step because it doesn't really cost anything.

 

Mine did it again yesterday, day 4 of a trip after 1500miles of towing with no troubles. I had "service advance trac" "pre-collision assist not available", "hill start assist not available" , "tow mode not available". Now today all works fine.

Obviously not a tire squat/diameter issue but likely a module "bug" that's intermittent. Shutting of the truck including opening and closing the doors does not "reset" the electronics but then next day "poof" it works fine. Will post what the dealer finds next week.

 

Let them know there is a TSB for this. I was pretty impressed that the dealer I go to took the initiative to call Ford.