Toyota AURIS HV Owner's Manual page 456

456
5-2. Using the audio system
Selecting a folder (MP3 and WMA or USB memory)
Press
1
Press and hold
2
CAUTION
 To reduce the risk of an accident
Exercise care when operating the audio switches on the steering wheel.
UK_AURIS/AURIS_HV_EE (OM12G88E)
to select CD or USB memory mode.
until you hear a beep.