When switched on, the rain sensor automatically shortens or lengthens the time between wiping
intervals depending on how hard it is raining ⇒ . The rain sensor's sensitivity can be adjusted
manually. Manual wiping (vehicles without rain sensors), see ⇒ Windshield wiper lever.
Push the lever into the desired position ⇒ fig. 80:
(A) Rain sensor off (windshield wiper lever home position).
(B) Rain sensor active – automatic wiping as needed.
(1) Adjust the sensitivity of the rain sensor:
– Move switch to the right – high sensitivity.
– Move switch to the left – low sensitivity.
After switching the ignition off and back on again, the rain sensor stays on and works again when the wiper lever is in position (B).
Possible reasons for changes in the way the rain sensor works
The rain sensor may misread what is happening in the detection zone of its sensitive rain-sensor
surface ⇒ fig. 81 (arrow) and not work for a number of reasons, which may include:
x Worn out wiper blades: Worn out wiper blades may leave a film of water or wiping streaks; this can cause the wipers to run longer, to wipe more often, or to wipe continuously at high speed.
x Insects: Insects hitting the windshield may trigger the wipers.
x Salt streaks: Salt streaks on the windshield from winter driving can cause wiping more often or continuously on glass that is almost dry.
x Dirt: Caked-on dust, wax, any other buildup on the windshield (lotus effect), or car-wash detergent residue can lower the rain sensor's sensitivity and cause it to react too slowly or not at all.
x Crack or chip in the windshield: If a stone hits and chips the windshield while the rain sensor is on, this will trigger a wiper cycle. After that, the rain sensor will recognize the change and recalibrate itself to respond to the sensitive surface's reduced detection zone. Depending on the size of the chip, the sensor's reaction pattern may or may not change.
WARNING
The rain sensor cannot always recognize rain and activate the wipers.
x Switch the wipers on manually when water on the windshield reduces visibility.
Clean the rain sensor's sensitive surface ⇒ fig. 81 (arrows) regularly and check the wiper blades for wear or damage.
To remove wax and coats of polish safely, we recommend using an alcohol-based windshield cleaner.
