Mercedes-Benz M-Class Operator's Manual page 84

SmartKey
82
Battery compartment cover
:
Mechanical key
;
Press mechanical key ; into the opening
X
in the SmartKey in the direction of the
arrow until battery compartment cover :
opens. Do not hold battery compartment
cover : closed while doing so.
Remove battery compartment cover :.
X
Battery
=
Repeatedly tap the SmartKey against your
X
palm until battery = falls out.
Insert the new battery with the positive
X
terminal facing upwards. Use a lint-free
cloth to do so.
Make sure that the surface of the battery is
X
free from lint, grease and all other forms of
contamination.
Insert the front tabs of battery
X
compartment cover : into the housing
first and then press to close it.
Insert mechanical key ; into the
X
SmartKey.
Check the function of all SmartKey buttons
X
on the vehicle.