I did some research on this several months back when I bought my 24x14 wide aftermarket wheels. The plan was to reverse them to face forward so I could see upcoming curbs and objects my wheel might otherwise get road rash. Bottom line, you cannot add them if they didn't come with the vehicle. There's a wiring harness leading from the vehicle inside the mirror that needs to exist. Not only that, but there's no way to program your existing camera system to include that extra view. You'd think that would be a feature included with the "towing package" to get those wide side angles, but sadly it's just a line graph added to the backup camera.
Hope that answers your question.
Not quite the same thing. I believe he is asking about the Rearview Mirror being switched to camera mode...which is an option in the Tech Package on the Denali and Standard on the High Country. Where, in the windshield mounted rearview mirror, you flip the lever (what we used to do when bright lights were reflecting in our face from a car behind us), and you get a camera view from what is behind you on the road, vs the mirror reflecting light. It is a useful feature if you have the 3rd row full of passengers, or the cargo area stuffed so you can't see out the rear window w/ a normal mirror. Although, I find it somewhat annoying, as it is a light source...and a bit unnatural looking, but does provide a view not available when blocked...so it does have its uses.
@Banks22, Not sure if the camera mounted in the back of the vehicles built without the camera mirror is only the down facing bumper/hitch cam, or if they also have the rear looking camera. I will take a pic of the camera module in mine...assuming the camera is there...then maybe swapping out the mirror would do it, but not sure. So much of this stuff runs through the infotainment system now, you may need a software update to pull it off...completely unclear...best to have that question answered by the dealer.
Looks like you need to have camera
P/N 84905646 present on the vehicle as well as the mirror, and probably some wiring harnesses, control modules, software enablement...not sure...