Exhaust ground wire???
 

While under my car trying to get my tranny in, I noticed a ground on my heat shield. The wire looks like it was cut. Anyone have any idea what this was for? Just curious. Seems like an odd place for a ground

There are several other grounds like this on the underside of the car, I would reconnect the ground. Nissan wouldn't have spent the money to put it there unless there was a good reason.

I would if I knew what it was from lol

It might have been for the oxygen sensor. Usually exhaust is touching engine and can ground this way, however there may be some kind of rubber isolation in the area(s) where oxygen sensors are installed. I can't see the ground having much to do with any of the other in car electronics. It might also just be acting as an electron "drain" of sorts, keeping the exhaust the same potential as the rest of the car to prevent some kind of buildup. I know from reading physics book that some race cars generate enough of an electron buildup in their chassis/tires to come back to the pits and cause a huge spark from the discharge, igniting fuel and causing mayhem etc...