You're supposed to change the transfer case oil. Then you go into special function for a VTG calibration, and it cycles the electronic clutches on and off inside the transfer case making some kinda Ka-Junka-Junka noise. Then you do a maintenance reset , and after that you should be able to clear the VTG Oil Wear code.
I'm not sure what the Valvetronic code you have but here is a video I made a year ago when I had an issue with one.
https://www.youtube.com/watch?v=xy35Ce9UOE0&t=80s