I had the same problem that started about 8 months ago. It's going in Tuesday to hopefully get fixed. If your problem is like mine, you might find yourself with a dead battery. I had to pull fuse 73....because there is a problem with my TCU. There's a SIB in this thread (which I've found on other forums but I can't find online to actually read it)
http://www.xoutpost.com/bmw-sav-foru...-failures.html
A few more related threads if your battery is draining too.
http://www.xoutpost.com/bmw-sav-foru...ery-drain.html
http://www.xoutpost.com/bmw-sav-foru...red-light.html