Is there a way to change the AWD system to make it an 'on demand only' system? From what I've read on this site, the AWD is a pita at best. And I've discovered if you talk to 6 GM technicians, you will get 6 different answers as to what the noise you hear might be. And one of the answers is, "They all make that noise". BS. If they did, GM wouldn't be able to sell any of them. I like my Denali but I don't want to spend a fortune trying to find out what the noise is.