John Lowder

I had similar issues in my 2021 GMC Sierra Denali. Dealer performed 2 software updates with continued intermittent SD card warnings and navigation failure. A second dealer evaluated the problem and found a card reader defect. This was replaced and I have been without any other issues. Problem solved!

Get AutoStop Eliminator. It lets you set the auto-stop to the on or off position and it will remain in that setting unless changed by the dash switch. I installed on my 2021 GMC Sierra 1500 Denali 3.0L in about 2 hours. Could be done much quicker if you have experience with the interior panels. There are multiple dash/console panels to remove to locate the switch behind the dash, but there are multiple installation videos that are very helpful. I hated the factory default to the on position after each start to the on position and the feature in itself.