I've had several chronic problems, dropping into 4x4 all by itself being the most problematic. Problem started when I would back out of a parking stall. Upon putting it in drive and moving forward, the transfer case would engage 4WD all by itself. The problem would sometimes occur when pulling up my inclined driveway, upon crossing the over the curb. Took it to the dealer multiple times, and was told it was a software issue, and they updated the transmission software each time. The problem would never show when I was at the dealer. Even took the mechanic on a drive with me, duplicating all the driving I had done when the problem arose. The dealer would do their "magic software update, but the issue would always return. They act all helpful, but never give you an answer until the 3rd or 4th service call, at which point you've dropped $600 on diagnostics alone, and wasted hours off work. Seems like they just want to wear you down so you eventually go away. I even spent over 2 hours on the phone with GM directly trying to get answers, and the incompetence runs even deeper at the Corporate level. I don't think Customer Service could have stepped someone through using their cup holder, let alone providing answers for a 4-wheel drive issue. After over a year of this 4WD drive problem, and four trips to the dealer, they said they had yet another new software update for the transfer case, and applied that. So far it's worked, but what a pain in the ass and dozens of hours wasted off work.