2008 GMC Sierra Denali tear wheel speed sensors

I have a 2008 GMC Sierra Denali and I have rear wheel speed sensor issue. My ABS light and traction control light are both on and will sometimes times go off for a while then come back on. I brought it to a friends shop and he put it on his scanner and it said both my rear sensors we not working. Which he though was weird that they both would fail at the same time. I told him the lights go off once in a while and then will turn back on. He said it sounds like a wiring issue so here is my question. Do these have a common ground or common power wire? I am pretty good with wiring so I was hopping someone could point me in the right direction.

I know on the W body GM's the wheel speed sensor/abs sensor wiring had a bad habit of corroding and breaking. I'm wondering if they share a harness going to the rear and you have some corrosion going on.

I think I am going to drop the rear tire and start chasing the wires forward and see where it gets me.