OK, 2017 F-150 2.7 XLT with tow package just went crazy. When I bought the truck a few months ago they said it had the tow package but needed the controller. I had the controller out of my 2004 F-150 Heritage and went to a local trailer dealer to get a new pigtail. Young man could not find it and unplugged and plugged in a couple connectors till his boss came out and reached behind a trim piece under the dash and pulled out the hookup. I just had him hook the new pigtail into the connector and I would hook up the rest when I decided where I would mount the actual controller. So the controller was never hooked up.
When I left I found my cruise control did not work and when I stopped I got a warning message the "hill start assist is not available." And I got a wrench symbol on the dash. If I shut the truck off it would clear the messages and the cruise would work till it was shut off with the brake or off switch then nothing. Sometimes it would work twice but then the "wrench light" would come on and not work again till the truck had been shut off. The young man checked the connectors to make sure they were all tight and they seem to be. They said if they caused it they will make it right and I have dealt with them before and had no trouble. I will be taking it to my dealer next Wednesday unless I figure things out. Happy to hear any suggestions. I don't know if it was from them hooking up the wire harness or if something else un-related just happened at that time, it could happen. Jim.

 

I wonder if things might reset if I disconnected the battery for a few minutes? Don't know if it would be a fix but don't think it would make any thing worse, might go out and try that later. Jim.

 

IMO. I have seen many posts that aftermarket TBC cause issues, even after Ford activates them, or one does it with Forscan. My guess is, that oem harness is not activated correctly. To be determined if brake controller you have plays well with it.

 

Nothing was actually activated, just hooked up the aftermarket harness, the controller itself was not attached. After I saw a problem surfaced I even removed the harness,.but that id not help. He id loosen some of the connectors but they all seem to be back where they belong and tight. Jim.

 

Went to local NAPA and they said their code reader does not read a lot of codes but it did not show any. I also disconnected the battery for a while and that did nothing except make me reset the clock. Jim.

 

All is good! I squeezed my old fat butt under the dash and checked all the connectors making sure they were all tight. Took a test ride and all is fine. Jim.

 

I hate working on stuff under the dash. Seems that the contortions required are not the kind of bending my body can do. If I have the time, I can remove the driver's seat and lay down a cushion or something.

 

I am going to take a stab at this and guess when the kid was unplugging and plugging things back in that he didn't get something tight or possibly bent some pins. Sounds like you have some on your back time looking under the dash, or a trip to the dealer. The other option is go back to the shop that messed it up and talk to the boss?