I just lost a tool bag out of the bed, when I forgot to close the tailgate. Stupid mistake. I know that I have a Hood Ajar, and Door Ajar sensor messages when I put my truck in Drive with things not buttoned up. Wouldn't you think Ford would have thought about a message when you take off with the tailgate not closed? GRRRRR!!!!!

 

The functionality is there you can add it. Forescan and some wiring.

 

OK, I am going to find out how to do this. What is "Forescan"?

 

There is a thread on adding the tailgate ajar message with wiring. I'm about to leave but search for that and if you can't find it, I'll search later.

 

I have a 2019 XLT and it was kind of there. It was there half ways.
When I bought my truck I bought a Bakflip cover for the bed. I was concerned immediately because it looks very easy to break in to. I wanted to tie it into the factory alarm.
I did some digging and asked some questions and somebody here told me about tailgate ajar. I had to find a specific wire in a specific connector under the dash by the glove box, and run a wire to the rear of the truck. Then I added tiny magnetic switches to the Bakflip cover and to the tailgate and wired them into my new alarm wire. The other side of the switches gets wired to ground. Then I had to enable something in Forescan.
It was an ordeal and I had forgotten all about it but it is there and working, now. If I leave the tailgate open or the Bakflip open I get a warning on my dash.
Search for tailgate ajar on this site and you should find something.
This might be it.
https://www.f150forum.com/f118/tailg...lariat-418742/

 

Found it! https://www.f150forum.com/f118/tailg...lariat-418742/

 

My 2019 XLT gives me a warning the minute I put the truck in reverse, so you must not have backed up first.

 

If I back up with the gate down, I'll be looking at the ground from the camera and I think the proximity sensors will also alarm. That isn't the same as a tailgate ajar message.

 

was just getting ready to post this very thought.

 

If you use your truck as a truck tailgate warning can get annoying.