I purchased a 2013 SXT last week and I started having issues with my 4.3S yesterday also. Mine is pretty much stuck on the satellite radio updating screen. If I switch to fm radio I can listen but after about 20-30 seconds the screen will freeze but continue to play music. The only way is to turn off the vehicle and wait for it to power down. If you happen to learn something at the dealership please let me know so I can get mine fixed also.
thanks in advance.