See also:

Making adjustments in 5 mph (Canada: 10 km/h) increments
Briefly press the cruise control lever beyond the pressure point, up 1 for a higher speed or down 2 for a lower speed. The last speed stored is increased or reduced. ...

Please bear the following in mind
At the onset of winter, have your vehicle winterproofed at a qualified specialist workshop, e.g. at an authorized Mercedes- Benz Center. Observe the notes in the "Changing a wheel" ...

System self-test
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 ...