Brake fluid level
If you notice that the brake
fluid level in
the brake fluid reservoir has fallen to the
MIN mark or less, check the brake system
immediately for leaks. Also check the
thickness of the brake linings. Contact a
qualified specialist workshop, e.g. an
authorized Mercedes-Benz Center
immediately.
Do not add brake fluid. This does not
correct the error.
Only check the brake fluid level when the vehicle is stationary and on a level surface.

The brake fluid level is correct if it is between MIN marking 2 and MAX marking 1 on the brake fluid reservoir.
See also:
Shifting to transmission position D
When the vehicle is stationary, depress the
brake pedal.
Push the DIRECT SELECT lever down past
the first point of resistance. ...
Important safety notes
The EASY-ENTRY/EXIT feature makes getting
in and out of your vehicle easier.
You can activate and deactivate the EASYENTRY/EXIT feature in the on-board
computer.
WARNING
You must make sure no ...
Removing the ball coupling
Observe the manufacturer's installation instructions.
Press the protective cap into the ball coupling recess.
Make sure that the protective cap is firmly in place.
...
