Purchased a new 8500BHS and had installed by a local shop yesterday. I have a Iphone 5 w/ IOS 7 and attached to a digital AV adapter them from the digital AV Adapter to HDMI and lighting connector to back of the head unit. USB1 lights up and when I select all I get is "format read." The 8500BHS never allows to access the music.

 

According to the documentation:

Pioneer's AVH-X8500BHS is ready to roll with direct connectivity to your iPod® or iPhone® for music and video via an optional USB interface cable depending on your iOS device (sold separately). Song, artist, time and album information are beautifully displayed on the 7" touchscreen. Powerful searching tools such as Link Play and Alphabet Search to help you find content faster. The system's wired USB connection provides direct digital signal transfer from the device for clean, clear sound while providing 1 amp of current to keep your iPod®/iPhone® charged

 

What am I missing here?

I have this same issue.

 

When I had my 4S connected to the stereo via Pioneer's 30pin adapter it all worked well. I could do app mode, and with app sound mixing control the volume of the iPod music or any other device I selected from the stereo.

 

When I switched to the 5S and started using the HDMI adapter this ability went away.

 

Now, perhaps if I turn off app sound mixing it would let me select USB1 to play music and/or allow me to control the volume if I use the Music app on the iPhone.

 

The quick and dirty solution for your problem is to go straight to the lightning cable, you'll get USB 1 back and be able to play that way, but won't have app mode.

 

Now, the question is, are we missing something obvious or did Pioneer not think this lighting solution through at all?