Someone else has it here, but no answer yet.

 

 

Doesn't seem to be for backup assist sensors; different pin count, and there's no sensors on the bumper in question.

 

maybe disconnect it, see what happens, dashboard lights up, a clue perhaps.

 

It is connected to nowhere, the cover is just water resistance. I could not even open the cover easily. Nowadays things are not too obvious, I pulled the yellow tap, still find no clue how to dislodge the cover. I think it is for some option like one reply saying it is a BSD option, Blind Spot Detection most likely. Thanks. Where can I invest a Service Manual?

 

Image search brings up this thread

https://www.promasterforum.com/threads/trailer-wiring.107190/

You could ask author if they have found what is it....

 

I got that, thank you, your link is to the Diver-side Rear bumper. Mine does not have that, it is for the Hitch. So I use a 3rd party wiring kits, already finish today. Thanks.

 

I had the same in my 2024 i bought in September. I went to a different dealer in January, who had over 50 to look at. I talked to the parts department who had no idea. I encouraged him to crawl under several of them with me so they knew I was not tampering with any. After looking at several with different options not on mine, the conclusion is that plug is for the back up sensors and or rear bumper cameras in the future. I put mine inside the van through the square hole it comes out off, because I have my 12 gauge 120 cords tucked under each side of the rear bumpers. Left side is power in to circuit breaker box. Right side is power out to use by a table outside the sliding door. To protect the plugs I connect a repair socket to each.

 

Thank you for the elaborated research~!