Hello, everyone I’m new to the board but I figured Id better jump on here since we have never ending issues With our Denali. Anyway this time there has been a buzzing every now under the bottom when driving after about a month of that now the car just all of a sudden shows that the service four-wheel-drive is on the dash also it’s stuck in 4 wheel high and it will not shift or change no matter what you do the lights on the shift selector only work in auto any ideas what it could be I know you have the actuator the switch or the transfer case control module, but I don’t wanna just start replacing parts until I find the issue and I’m not gonna take it to the Steeler to have them look at it I always make my own repairs just this one kind of has me stuck. I e tried pulling the #6 fuse along with a few other things so far nothing has helped as far as getting back in 2wd. Any help would be greatly appreciated!