My problem isn't exactly with the USB connection to the unit but what happens as I try to play the music off of it. I placed 20 songs on the USB as a test. They are the same ones I listen to on my phone. The pioneer system sees the 20 songs and shows the data from the but of the 20, it only places about 4-5 of the 20. That isn't a good average considering that I have about 16GB worth of songs. Is there something I'm missing? Also, the installers said I can trandfer all of my music to the pioneer system but not exactly sure how that is done. Thanks for any assistance.