I have recently bought a 2013 grand cmax with the sony head unit (non sat nav one). I liked the fact that it could read files from a USB stick.
I went out and got a Kingston 64GB usb memory stick (£19 from amazon) and copied my files into the format of Artist-Album-Song Title. I also formatted the USB stick to FAT 32 as I had read on a few forums.
When I first put the memory stick in it worked fine, spent a few seconds initialising and then a few minutes indexing the tracks. Then I could search through all the files and play what I wanted.
However the next day when I went in the car wouldn't play anything and said that there was no USB present even when I was plugging / unplugging trying to get a response. Occasionally it will say it has found the stick but it is not recognised and other times just denies it exists!!
I have no idea why it is doing this, it worked fine the first time but then just had a hissy fit. There seems to be no advice or set up recommendations on the ford website either so I've come here to see if anyone knows what to do! Its been a few days now and I'm stumped.