Mystery wiring harness on new Yukon near steering column

[neal alexander]

I purchased a new Yukon, dealer demo with 3000 miles. I noticed an 8 pin wiring harness (female) coming from the enclosure with the electronics to the right of the steering column. I posted a photo, it has a little clock on the plastic plug with an arrow pointing to the '1' and the number 15 stamped on it. Wires are Black, Green, Brown, Blue, Blue Black and Yellow. What is it for? The dealer did not know and the service record showed nothing.

Also, when I took it home I found another harness in the back area, called a 282 jumper, which I think is a trailer brake controller. I have the towing equipment, but now not sure if it is all connected rights. Can I install my own brake controller later if I happen to find the need to do so, using that harness?

 

[sumo]

The clock symbol is a stamp date when it was made. January of 2015. As far as the connector, not sure

 

[mizzouguy]

My 04 had a harness in the back storage compartment for adding a non-factory brake controller. Looked similar to that one. If the wires are blue, red, white, and black, its for a controller.