2021 F150 trailer disconnect alarm issues

[Tvov]

So, last fall I bought a 2021 F150 XLT 2.7. It comes with an amazing amount electronic "stuff", including a bunch of stuff related to towing. One weird thing is, with all the towing / trailer sensors and features, it doesn't have a built in brake controller?! That is silly, but....

It has a "trailer disconnect alarm". I am still figuring it out, but it alarms if the trailer becomes disconnected from the truck. Ford advertises it as a "security" feature, so if the truck and trailer is parked somewhere and someone tries to disconnect and steal the trailer, the truck lights and horn flash and beep. Okay, fine.

Problem is, if I park my truck and utility trailer in my driveway, leave it connected, and walk into the house... a few minutes later the truck's trailer theft alarm turns on. So I thought if I just unplugged the trailer plug it would be fine... Nope! Then the trailer disconnect alarm sounds!!

I have found that I have to unhitch the trailer and then pull the truck away from the trailer so the alarm doesn't activate.

Looking online, one guy figured out that if he locked and unlocked the truck 3 times in a row the trailer alarm shuts off, lol (?). Turns out, a LOT of people are having similar issues with the trailer alarm. I guess it is new for 2021.

I can't find anywhere in the dashboard multi function display where to just shut off the alarm entirely.

I have emailed Ford asking about this yesterday, haven't gotten a reply yet.

Has anyone else run into this, and have you figured out how to deal with it?

[Tvov]

Just found something else about this.

I need to try unplugging the trailer before I lock the truck.

Another odd thing about this is the alarm hasn't gone off when I've been at jobsites with the equipment trailer.

[Tvov]

Mike134 wrote:
Apparently, it is a programming error

https://online.sodapdf.com/document/1cdcc1bc-e69d-4e89-b1d7-7019f7a5e503?url=https:%2F%2Fford.oemdtc.com%2F7459%2Ffalse-alarm-activation-with-a-trailer-connected-2021-ford-f-150&uid=1019974&cmp=spdf_all_partners_all_all_all_infolinks

I'm getting "server not found"... can you get a different link or copy the information? Thanks!

[Mike134]

Apparently, it is a programming error

https://online.sodapdf.com/document/1cdcc1bc-e69d-4e89-b1d7-7019f7a5e503?url=https:%2F%2Fford.oemdtc.com%2F7459%2Ffalse-alarm-activation-with-a-trailer-connected-2021-ford-f-150&uid=1019974&cmp=spdf_all_partners_all_all_all_infolinks

[Tvov]

I have looked through the owner's "manual"... these days, the "manual" is in the multi-function display screen, and I find it very hard to scroll through screen after screen looking for what I want.

I actually downloaded the manual in PDF form onto my computer and it is a little better looking for things, but to my old fashioned brain looking through an actual book is easier.

The owner's manual simply says that the truck has a trailer disconnect alarm.

One thing I did find was that you can setup the truck for different trailers, and there are options to turn on and off with the different trailers. But I just saw that last night and haven't had a chance to check on that.

Funny (or not) on one of the Ford online forums a guy pulled in late to a campground, left the truck and trailer connected to leave early, got into bed in the trailer and then the truck's trailer alarm went off. He jumped out of bed and disconnected the truck completely and pulled it away from the trailer so it wouldn't turn on again.

That is one of the odd things about this alarm... sometimes it waits 5 or 10 minutes before going off. You'd think a "theft" alarm would immediately activate.

So I'm still trying to figure this all out.

[opnspaces]

I'm sure you've probably tried all variants of disconnecting. But I find it extremely difficult to believe that the design engineers missed this, then the testing department missed it during testing.

First question: Have you looked in the owners manual to see if it is mentioned? Don't just rely on the popular forums as all too often people just parrot what they have read on the forum and nobody actually verifies that it is correct.


My only idea, what if you park in the driveway and disconnect the trailer plug with the engine still running. The alarm probably sounds. Then turn the truck off get out and lock the doors? Does the alarm turn off?

Going with the three time idea, try parking and turning off the ignition and removing the key. Then walk back and unplug the trailer. Then get back in the drivers seat and turn the key to run then off then run three times finally ending with it off after the third time. Remove the key, get out and lock the doors.

Good luck with it. I guarantee you Ford has this figured out you just have to find the document.

[Fisherman]

And we wonder why nothing really works properly with the nitwits inventing useless trinkets.

[specta]

Some of the warnings are soo stupid its almost a joke.

When I start this truck it says "trailer connected". If you are soo stupid that you need to be told that your trailer is either connected or disconnected you really shouldn't be driving in the first place.