See also:

Treadwear indicators
Narrow bars (tread wear bars) that are distributed over the tire tread. If the tire tread is level with the bars, the wear limit of 1/16 in (1.6 mm) has been reached. ...

Deactivating/activating PARKTRONIC
Deactivating/activating PARKTRONIC 1 Indicator lamp 2 To deactivate/activate PARKTRONIC If indicator lamp 1 lights up, PARKTRONIC is deactivated. Parking Guidance is also deactivated. PARKT ...

The windshield wipers are inoperative
The windshield wiper drive is malfunctioning. Select another wiper speed on the combination switch. Have the windshield wipers checked at a qualified specialist workshop. ...