Mazda 2015 5 Owner's Manual page 241

Interior Comfort
Audio System
Message display
If CHECK CD is displayed, it means
that there is some CD malfunction. Check
the CD for damage, dirt, or smudges, and
then properly reinsert. If the message
appears again, take the unit to an
Authorized Mazda Dealer for service.
qOperating the Auxiliary jack/
USB port
Audio can be heard from the vehicle's
speakers by connecting a commercially-
available portable audio unit to the
auxiliary jack.
Use a commercially-available, non-
impedance (3.5 ) stereo mini plug cable.
Contact an Authorized Mazda Dealer for
details.
In addition, audio can be played from the
vehicle's audio unit by connecting USB
device or an iPod to the USB port.
Refer to AUX/USB/iPod Mode on page
6-50.
6-45