Nav System radio will not shut off

[Pascpa]

I just purchased 2012 Denali. Turning off radio turns off nav sustem. Dealer told me to turn volume down. My wife's 2007 Honda does not have this issue.

Also, I notice many small chimes coming from nav system. Is this normal?

Is there a way to load different software to change the interface on the Nav? The Honda graphically shows which lane to get in when approaching exit on interstate. The installed system does not.

I hope i did not make a $45K mistake

 

[Denali24]

I also have a 2012 Denali and owners manual says to push the volume button to shut of the radio and leave the Nav on, hold the button down for several seconds and both nav and radio go off. Mine turns off everything when you push the volume button. Nobody can answer why.