Ram Trucks 2014 ProMaster Commercial - Owner Manual - Manual (Page 160)

In USB mode, the radio plays MP3, WMA and AAC files
stored on the device connected to the USB port that is
located inside the glove compartment of the vehicle.
To enter USB mode, you must press the SRC button.
When you enter USB mode, the display shows
ЉLOAD-
ING
Љ while the radio checks whether the connected
device is valid.
If there is no USB device, an invalid USB device, or a
valid device that is defective, the display will show
ЉERR
USB Љ for two seconds and the radio remains in TUNER
mode. If a valid device does not contain any playable
files (i.e. MP3, WMA or AAC), the display will show
ЉNO
MUSIC Љ for two seconds and the radio remains in
TUNER mode.
If playable files are found, the radio will also check that
the connected device is the same as the one used imme-
diately before the USB function. If this is the case, music
playback will start from the point where it was inter-
rupted (file and music runtime). If not, the file played
will be the first valid file, in the sequence shown in the
following example:
158 UNDERSTANDING YOUR INSTRUMENT PANEL