Audio Unit
WARNING: This page is about a different car, the 2008 Acura TL and 2007 Acura TL. However, it is still accessible from the selected car via links, so may be relevant.
The audio unit receives the voice guidance instructions from the navigation unit and transmits the instructions through the center speaker even when the audio system is in use.
NOTE:
If the navigation volume is turned OFF, this feature is disabled.