This unit plays audio files as follows:

CAUTION
Do not use an audio file extension on files other than audio files. In addition, do not change the audio file extension. Otherwise, the unit will not recognize the file correctly resulting in noise or a malfunction.
NOTE
MP3/WMA/AAC/OGG files written under specifications other than the indicated specification may not play normally or files/folder names may not display correctly.
Operating Tips for OGG
Audio SetMazda 6 Owners Manual: Warning Light and Brake Pad Wear Indicator
Warning Light
The warning light turns on when the system has a malfunction.
Refer to Warning Indication/Warning Lights
Brake Pad Wear Indicator
When the disc brake pads become worn, the built-in wear indicators contact the
disc plates. This causes a screeching noise to warn that the pads shoul ...
Mazda 6 Owners Manual: Cruise control switch inspection
1. Disconnect the negative battery cable.
2. Remove the driver-side air bag module. (See DRIVER-SIDE AIR BAG MODULE
REMOVAL/INSTALLATION.)
3. Disconnect the cruise control switch connector.
4. Inspect for resistance and continuity between the cruise control switch
terminals using an ohmmeter. ...