Windshield Washer, Function - GF82.35-P-3002FH

Model 238 

Up To Model Year 2021 

Function requirements, general 

• Circuit 15R On:

  The electronic ignition lock control unit (N73) sends the status of circuit 15 via interior CAN (CAN B) to the front SAM control unit (N10/6).

Washing windshield, general 

The windshield wash function is comprised of the following subfunctions:

• Washing function sequence 
• Afterwiping function sequence 
• Function sequence for interrupting washing during engine start 
• Function sequence for wash stop 

Washing function sequence 

The washing function is activated by pressing the combination switch (S4) in axial direction beyond the detent point.

The steering column tube module control unit (N80) directly reads in the switch position of the combination switch and sends it to the front SAM control unit via the chassis FlexRay (Flex E), electronic ignition lock control unit and interior CAN.

The front SAM control unit then directly actuates the windshield washer system pump (M5/1) and simultaneously the wiper motor (M6/1) over the rain/light sensor LIN (LIN B16).

Model 238.3

up to model year 2021

with code 413 (Panoramic sliding sunroof/glass roof)

Model 238.4

up to model year 2021

The delivery rate of the windshield washer system pump is reduced with the panoramic sliding sunroof or soft top open. This takes place through reduction of the actuation time of the windshield washer system pump. The ingress of splash water in the vehicle interior is thereby prevented.

If a "Washer fluid level below minimum" is detected via the windshield washer system washer fluid level check switch (S42), the front SAM control unit still actuates the windshield washer system pump. The washer fluid level switch is a so-called two-pin sensor with two metal pins that are surrounded by washer fluid when the washer fluid reservoir is filled.

During washing, wiping takes place with the wiper speed set on the combination switch or in stage "3".

The washing function is interrupted under the following conditions or aborted after t = 15 s:

• Activation of the washer interruption function when the engine starts
• Activating wipe/stop function
• "Combination switch stuck" detection

Afterwiping function sequence 

The afterwiping function is activated as soon as the combination switch is no longer activated.

The number of afterwipe cycles depends on the combination switch actuation time:

• Actuation time t < 200 ms: Afterwiping does not take place.
• Actuation time t < 1 s: Afterwiping takes place once.
• Actuation time t > 1 s: Afterwiping takes place three times.

The front SAM control unit sends the "Afterwiping" status via rain/light sensor LIN to the rain/light sensor with additional functions (B38/2). Wipe requests from the rain sensor (B38/2b1) in the rain/light sensor with additional functions are not taken into account during afterwiping.

Afterwiping takes place with the wiper speed set on the combination switch. When the combination switch is in the rest position, afterwiping takes place with speed "3".

The afterwiping function is interrupted or aborted under the following conditions:

• Activation of the washer interruption function when the engine starts
• Blocking of wiper motor
• Activating wash function
• Activating wipe/stop function

Function sequence for interrupting washing during engine start 

When the engine starts, the front SAM control unit blocks the actuation of the windshield washer system pump and the actuation of the wiper motor.

Any wiping procedure that has already started is terminated.

The engine start is recognized by the transmission of the status of circuit 50. The electronic ignition lock control unit transmits the status of circuit 50 to the front SAM control unit via the interior CAN.

Function sequence for wash stop 

When the engine hood is opened during windshield washing, the front SAM control unit interrupts the actuation of the windshield washer system pump and the actuation of the wiper motor. Opening the engine hood is recognized by the right engine hood contact switch (S62/42) or the left engine hood contact switch (S62/43). The front SAM control unit directly reads in the status of the right engine hood contact switch and the left engine hood contact switch.

If the engine hood is closed, the windshield washer system pump can be actuated again. This is also possible if the engine hood is open and the vehicle speed exceeds v = 8 km/h.

The instrument cluster (A1) sends the vehicle speed to the front SAM control unit over the user interface CAN (CAN HMI), electronic ignition lock control unit and interior CAN.

	Electrical function schematic for windshield washer		PE82.35-P-2051-97DCA
	Overview of system components for windshield wiper system		GF82.30-P-9996FH