Trailer detected when not present & safety features deactivated (2025 Hybrid)

[Wild Oar]

Howdy, I have a Green 2025 XLT AWD Hybrid with an ARE MX shell/cap. Got the truck in February and the shell in August. After towing my boat for the first time a few months back, I started getting some apparent electrical issues. After disconnecting the trailer and wiring, the next time I started the truck I got these notifications: (1) "Cross-Traffic Alert deactivated, trailer attached" , (2) "Trailer Left Turn Lamps fault; Check lamps" and (3) "Trailer Right Turn Lamps fault...." The blind spot indicator was also deactivated. Finally, I get a rapid blinker when using turn signal. I figured out that these warnings go away when I unplug the brake light wiring for my shell. And, sometimes, after turning it off and plugging it back in, things continue to work normally. But sometimes they don't. Or it will work normally for a few days, then randomly (while driving) start giving me these warnings and the rapid blinker issue. Anyone else experience this problem? Any solutions/recommendations? I did search the threads, but couldn't find previous posts on this topic.

p.s. I really appreciate this forum and the shared knowledge on here. I used it extensively before deciding to buy my Maverick and when researching my shell and other components. At some point, I will post some photos and provide my impressions of the truck (mostly positive) and ARE MX shell (not all positive). I'm at about 6000 miles.

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[padcarroll]

Is it possible you have lost the ground for the cap light? I had a similar issue trying to use a tailgate LED light strip. I was told that you can't mix LED and incandescent lights on the same circuit.

 

[Sticks]

The truck knows that a trailer is connected when power is being drawn from the trailer lamp connector. Most new trucks for the last 5+ years function like this.

It sounds like your installer plugged the cap's 3rd brake light into the trailer connector. If the power draw is very low, it might trigger towing mode occasionally, but not every time. Companies in this industry should know better by now -- They should typically draw power from other sources (like the tail lights) instead.

 

[rgmiller32]

On our work trucks with ARE caps the third brake light is wired into a special wire connection, that the vehicle manufacturers tell the cap manufacturers to connect into. This is wire was not at the trailer connectors. On the Ford he had to run three wires up to engine compartment for the connections. One for ground, one for 12 volt power and one to the third brake light feed wire. The Ford a short wire sticking out of the harness for this. The 12 volt power was picked up from a accessory power post and the ground to the chassis ground post.

He said if wired into the rear of the truck it would cause the truck to think a trailer was connected.

One the two Rams there were spots to hook up near the rear of the truck near the left rear tail light. And the the Chevy it was near the rear of the cab on the frame rail.

Not sure if the Maverick has this same setup.

 

[Wild Oar]

Appreciate the info everyone. This will be helpful when going back to my installer to resolve the issue.

 

[BlueSpec1]

It appears that the BLIS, CTA stuff gets errors unless some kind of adapter that connects to the left and right tail lights.
Or
Tap into the 3rd brake light (CHMSL) wiring up at the light or down at the BCM.

Service Manual > Wiring Diagrams > Turn Signal/Stop/Hazard Lights, C2280F Body Control Module.

BCM/Fusebox on front below passenger foot area:

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