Dirtleg82

Hi all. I'm new to forum but I'm having this issue now in my new 2016 GMC Sierra Denali 1500 Crew Cab. I recently had a software update to be able to use the projection function and two days later, my screen was blank. My steering wheel controls still work but radio buttons and screen is out. I seen on here that unhooking the battery for a few hours helped...not in my situation. I even unhook both battery post overnight....still nothing. The vehicle now has been at the dealership for 6 days. They are unsure what the problem is. Any help will be greatly appreciated. Thanks.