The windshield wipers are inoperative

The windshield wiper drive is malfunctioning.

the Select another wiper speed on the combination switch.
at a Have the windshield wipers checked at a qualified specialist workshop.

    See also:

    M-Class in the Market
    It's a bitter pill for a reviewer to swallow when you see a test car do so many things so right, yet fall short in a few key areas. Most shoppers — even most car reviewers — won't get to spend as ...

    Checking the coolant level
    Only check the coolant level when the vehicle is on a level surface and the engine has cooled down. Turn the SmartKey to position 2 in the ignition lock. On vehicles with KEYLESS-GO, press ...

    Changing the set speed whilethe vehicle is in motion
    When DSR is activated, the control speed can be changed to a value between 3 mph and 10 mph (Canada: between 4 km/h and 18 km/h) during the journey. ► To increase or decrease in 1 mph (Ca ...