See also:

License plate lamps
Switch off the lights. Open the tailgate. Press lug 2 of license plate lamp 1 in the direction of the arrow and remove license plate lamp lens 1. Remove license plate lamp lens 1. Repl ...

Mercedes-Benz M-Class Owners Manual
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Closing the DEF filler cap and fuel filler flap
– Place DEF filler cap 2 on the filler neck and turn it clockwise. – To close the fuel filler flap, press it in the direction of arrow 1. – Drive at a speed above 10 mph (16 km/h). The Check ...