Wiper system automatic speed reduction, function Without code (494) USA version - GF82.30-P-4006RC

MODEL 171.4 as of model year 09/YoM 08 model refinement package except CODE (494) USA version 

Function requirements, general:  C. 15R On Combination switch (S4) in position "1", "2" or "3" Speed reduction from v > 8 km/h to v < 5 km/h

Automatic wiper speed reduction, general:  The automatic speed reduction is activated at a speed reduction from v > 8 km/h to v < 5 km/h, because at this speed the windshield is normally not very wet.

Automatic wiper speed reduction comprises the following subfunctions:  Function sequence for automatic wiper speed reduction, general; Function sequence for deactivating automatic wiper speed reduction.

Function sequence for automatic wiper speed reduction, general:  If the driver SAM control unit with fuse and relay module (N10/1) detects a speed reduction from v > 8 km/h to v < 5 km/h, then the driver SAM control unit switches the wiper motor (M6/1) back one stage.

Function sequence for deactivating automatic wiper speed reduction:  Actuation of the wiper motor at the speed before automatic speed reduction is accomplished by one of the following events: Speed v > 8 km/h - Changing wiper speed.

The vehicle speed is sent by the instrument cluster (A1) to the interior CAN and read in by the driver SAM control unit. The status of the combination switch is read in by the steering column tube module (N80) and sent over the interior CAN to the driver SAM control unit. This evaluates the signals and actuates the wiper motor accordingly.