Hi,

I have a 8gb usb sandisk pen drive and a 250gb USB Hard Drive 2,5". Whenever I plug them in to the USB on my AVH-8400BT it says ERROR-02-D0, The user's guide says nothing about this error, and it is driving me crazy. 

Both pen drive and hard disk are FAT32 formatted, but still don't work.

Any help?

Problem solved, I was using a USB extension cable. Removing this cable, the USB flash drive is working properly and the hard disk has been necessary to connect a second USB power from the cigarette lighter.