Purpose of the System

Windshield Wiping/Washing

Purpose of the System
The windshield wiping/washing functions are controlled by the GM III when the ignition is in position KL R or KL15. The system has four wiping stages and four interval wiping speeds. The wiper motor output control is through two relays (double relay > 98 MY, except E38) that are located in the Electronics box (E box).

The Windshield Wiping System can also be supplemented with the Rain Sensor system as optional equipment. The Rain Sensor detects rain drops on the windshield and automatically activates the wipers when the stalk switch is in the intermittent position.

System Components




Wiper Stalk Switch Input: The wiping stage inputs are coded signals through a two wire link with a combination of high/low inputs. The wiping stages include:

Single (S): Momentarily holding the wiper switch down in the single position provides a momentary ground signal to activate a single sweep in slow speed.

Slow (I) and Fast (II): The stage I and stage II wiping speeds are road speed dependent. Stage I switches to intermittent when the vehicle is stopped and stage II switches to stage I when stopped.

Windshield Washing: The wash request provides a switched ground input to the GM by pulling the stalk rearward. The GM activates the windshield washer pump directly.


Intermittent (Int): The intermittent wiping time inputs are provided by a potentiometer mounted in the wiper stalk switch (1 through 4). The intermittent wiping intervals are also dependent on the road speed. As road speed increases, the wiping interval is shortened.





System Components: Inputs - Processing - Outputs