Windshield wiper (WS) system, function - GF82.30-P-2300MCU

MODEL 451.3 /4

Fig 1: Windshield Wiper System Function Chart

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Function requirements:

Circuit 15 On

Functions

Wiping
Wiping with washer fluid
Intermittent wipe

Wiping

When the wiper switch is moved upwards, the wiper can be activated at 2 different speeds. In position 1 wiping takes place at slow speed, and in position 2 wiping takes place at fast speed.

The request is read in by the SAM control unit, which actuates the wiper motor directly.

The next slower wiping speed is selected if the vehicle is stationary. The wiper is actuated in accordance with the request at speeds of 5 km/h and above.

Switching back to position 0 deactivates the wiper function. If deactivation takes place during a wiper operation, the wiper motor is not switched off until the park position has been reached. Park position feedback is provided by a signal contact integrated in the wiper motor.

Wiping with washer fluid

The window washer fluid pump is actuated directly by pulling the wiper switch backwards and holding it in position. Actuation takes place for as long as the switch is held in this position.

At the same time, the SAM control unit actuates the wiper motor with a time delay of approx. 0.2 s. The wiper motor is actuated for an additional 3 wipe cycles at the end of the request.

If the wipe request was made by tapping the wiper switch, only one wipe cycle is performed.

Intermittent wipe

(in vehicles without code (V54) Rain/light sensor)

Moving the wiper switch downwards requests the intermittent wipe function. The wiping interval is speed-dependent and decreases as the speed increases.

The following wiping intervals are implemented by the SAM control unit:

Wipe every 15 s at v = 0 km/h
Wipe every 12 s at v > 5 km/h
Wipe every 7 s at v > 50 km/h
Wipe every 5 s at v > 75 km/h

Intermittent wipe

(in vehicles with code (V54) Rain/ light sensor)

Moving the wiper switch downwards requests the intermittent wipe function. The wiping interval depends on the wetness of the windshield. The rain/light sensor determines the wetness of the windshield and relays the activation request to the SAM control unit via LIN B. This actuates the wiper motor accordingly.

The rail/light sensor does not issue an activation request if a wipe request with washer fluid is active. The status of the wiper motor is transferred to the rain/light sensor by the SAM control unit via LIN B.

Instrument cluster, component description	A1	GF54.30-P-6000MCU
Rain/light sensor, component description	B38 For vehicles with code (V54) Rain/light sensor	GF54.21-P-6000MCC
Windshield washer fluid pump, component description	M5/1	GF82.35-P-5000MCC
Wiper motor, component description	M6/1	GF82.30-P-5010MCC
SAM control unit, component description	N10/10	GF54.21-P-4157MCU
Wiper switch, component description	S4/4	GF82.30-P-5002MCC