System self-test
The 
indicator lamp illuminates
when you:
- turn the SmartKey to position 1 or 2 in the
ignition lock
- on vehicles with KEYLESS-GO, press the
Start/Stop button once or twice
If an adult occupant is properly sitting on the
passenger seat and the OCS classifies the
occupant as an adult, the indicator
lamp illuminates and goes out again after
approximately 6 seconds.
If the seat is not occupied and the OCS
classifies the front passenger seat as being
unoccupied, the indicator lamp
will illuminate and not go out.
WARNING
If the indicator lamp does
not
illuminate, the system is not functioning. You
must contact an authorized Mercedes-Benz
Center before seating any child on the front
passenger seat.
For more information, see "Problems with the Occupant Classification System"
WARNING
Never place anything between seat cushion
and child seat (e.g. a pillow), since it reduces
the effectiveness of the OCS. The underside
and rear side child restraint system must be
placed entirely on the seat cushion and the
backrest of the front-passenger seat
backrest.
If necessary, adjust the tilt of the passenger seat backrest.
An incorrectly mounted child seat could cause injuries to the child in case of an accident, instead of increasing protection for the child.
Follow the manufacturer's instructions for installation of child restraint systems.
See also:
Removing the mechanical key
Push release catch 1 in the direction of the arrow and at the same time,
remove mechanical key 2 from the SmartKey.
...
Vehicle equipment
This Operator's Manual describes all models
and all standard and optional equipment of
your vehicle available at the time of
publication of the Operator's Manual.
Country-specific differences a ...
Securing hooks
Only use the mounting hooks to secure items
of luggage up to maximum of 9 lbs (4 kg) in
weight.
There are two securing hooks 1 on each side
of the cargo compartment. ...