This is what the manual says:
Portable audio player compatibility
! Make inquiries to the manufacturer about
your USB portable audio player/USB mem-
ory.
This unit corresponds to the following.
— USB MSC (Mass Storage Class) compliant
portable audio player and memor y
— WMA, MP3 and AAC file playback
— JPEG file playback The SAT RADIO READY mark indicates that
more
You can play back MP3 files recorded on CD-
R/RW/ROM (ISO9660 Level 1/Level 2 stan-
dard), DVD-R/RW/ROM (ISO9660 Level 1/Level
2 standard, UDF 1.02) and USB storage device
(FAT 16, FAT 32).
Portable audio player compatibility on page 9.
Operation of JPEG in a USB storage device is
the same as JPEG on a disc.
1 Source icon
Shows the media type currently playing.
2 Folder number indicator
Shows the folder number currently playing.
3 File number indicator
Shows the file number currently playing.
! Last four-digit can be displayed as the
file number.
4 Play time indicator
Shows the elapsed playing time of the cur-
rent file.
5 Song information
Shows detailed information of currently
playing song.
Notes
! Optimum performance of this unit may not be
obtained depending on the connected USB
portable audio player/USB memory.
! If folder 01 (ROOT) contains no files, playback
commences with folder 02.
! If an error message or icon is displayed, refer
to Error messages on page 96.
! When the USB portable audio player having
battery charging function is connected to this
unit and the ignition switch is set to ACC or
ON, the battery is charged.
! You can disconnect the USB portable audio
player/USB memor y anytime you want to fin-
ish listening to it.
! If the characters recorded on the audio file are
not compatible with this unit, those charac-
ters will not be displayed.
! Text information may not be correctly dis-
played depending on the recorded en-
vironment.
This is everything that's usb related on the manual.
I don't know what to do