If I can't figure out how a feature works, I refer to the manual that came with my truck. After following the directions and the function is, or appears to be, malfunctioning I take my truck to the nearest dealership service department for assistance. I would not allow any new vehicle under warranty to be a piece of junk. I have purchased new vehicles (not necessarily GM) which have had an inordinate amount of warranty work required, but I always drive vehicles that operate properly. I am particularly concerned about how a vehicle holds up after the warranty period has expired. For me, GM's have always excelled in the long haul! Your Tahoe and Silverado are both great vehicles. The frustrations you have experienced can be fixed.