Hello!

I am at a point in my diagnosis here that I need a little outside help.

A couple of weeks ago, my backup camera and Park sensors stopped working.

I had the wife check reverse lights, and they were also out.

The first thing I figured was that it's the switch on the side of the G56 trans.

I pulled it and checked that when it's all the way out, I had continuity, and when I depress the brass switch, it goes open circuit.

I also tried jumping across terminals to see if lights would come on.

Then I checked the wiring side of the plug. I have no voltage at either pin with the ignition on.

One of the wires has .5 ohms resistance to chassis ground, and the other is open, so either the system is ground side controlled, or a wire is shorted to ground.

I do not want to jump 12 volts to a ground circuit and find out if I don't know for sure.

Using my Verus scanner, I went into the BCM, which I figure must be the controller for this system, and could activate left and right reverse lights through a function test, which means wiring to tail lights are probably good.

No faults stored.

Live data for the reverse switch does not change when putting the truck in reverse.

So my question is, is the system, in fact, controlled with 12v or ground? Second, does anyone have a wiring diagram for the BCM/ reverse switch to trace for wire breaks/shorts to the ground?

Where is the BCM located?

Side note: Around 3 weeks ago, my keyless entry fob stopped working and then started working again a few days later—no issue since... not sure if my BCM is crapping out.

I really appreciate any help you can provide.

I really don't think my local dealer will figure it out since they have been terrible from my experience.