See also:

Activating audio CD/DVD or MP3 mode
Option 1 Insert a CD/DVD or an SD card or connect a USB device. COMAND loads the medium inserted and starts to play it. Option 2 Press the function button once or twice. Select an aud ...

Mercedes-Benz M-Class Owners Manual
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Locking the vehicle (mechanical key)
If the vehicle can no longer be locked with the SmartKey, use the mechanical key. Open the driver's door. Close the front-passenger door, the rear doors and the tailgate. Press the locki ...