Volume through car speakers very low when using AA for navigation in 2016 Honda Accord

[AC Question]

I have a new Samsung Galaxy Grand Prime with Android 5.1.1 and running Android Auto in order to use the navigation feature in a new 2016 Honda Accord E-XL. I had no problems getting AA and the car to "see" each other and no other link or other problems -- except, the volume from the car speakers is just a whisper when using Google Maps with audio directions. I have turned the volume to maximum on the phone itself (including the four sub-volume controls for Bluetooth, etc.) and the car head system volume to maximum as well, but the navigation volume coming from the phone is basically so low as to be inaudible. Anyone have a fix for this problem?