Hey
You have to play with it. That or read the manual. There is a screen that you access that allows you to choose the North East, South East, Mid West and West Coast .... something along those lines. The way it is now, you can see limited navigation on your screen for where you physically are located . And if you type an address into it to drive to, chances are it will not be found, as it is accessing that area (region/zone) which is selected in the unit.
When you find that screen there will be an outline of the US toward the lower right of that screen . It is there you select your region/zone.
When up and running, it works well. You can get a later date update Nav Disc other than that offered by GM as late as 2015. It is a two disk set put out by Toyota. If you want I will find the place at E-Bay that sells them about 11 bucks and let you know if you want.
Bill