CITROEN DS3 Owner's Handbook Manual page 296

05 USB BOX
USING THE AUXILIARY INPUT (AUX)
JACK SOCKET OR USB PORT (according to vehicle)
The auxiliary input, JACK or USB, allows the connection of
portable equipment (MP3 player...).
Do not connect a single piece of equipment via the JACK socket
and the USB port at the same time.
1
Connect the portable equipment
(MP3 player...) to the JACK
socket or to the USB port, using
a suitable cable (not supplied).
2
Press the SOURCE button several
times in succession and select AUX.
ADJUSTING THE VOLUME OF THE
AUXILIARY SOURCE
1
First adjust the volume of your portable device.
2
Then adjust the volume of your audio
system.
The display and control is via the portable device.