Mercedes-Benz R-Class 2012 Owners Manual - Manual (Page 129)

X For safety reasons, you should remove the
SmartKey from the ignition lock.
or
X Switch off the engine using the Start/Stop
button and open the driver's door.
X Remove the cause of the obstruction.
X Switch the windshield wipers back on.
The windshield wipers are inoperative
The windshield wiper drive is malfunctioning.
X Select another wiper speed on the
combination switch.
X Have the windshield wipers checked at a
qualified specialist workshop.
The spray nozzles are misaligned
The windshield washer fluid from the spray
nozzles no longer hits the center of the
windshield. The spray nozzles are misaligned.
X Have the spray nozzles adjusted at a
qualified specialist workshop.
Windshield wipers
127
Lights and windshield wipers
Z