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

Model 166 

as of model year 2016 

Model 292 

Function requirements, general 

• Circuit 15R ON

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

Washing windshield, general 

The windshield is kept clean by washing the windshield.

Wiper blade (shown with CODE 874 (MAGIC VISION CONTROL, heated)) 

Courtesy of MERCEDES-BENZ USA

The windshield wash function is comprised of the following subfunctions:

• Function sequence for washing (without CODE 874 (MAGIC VISION CONTROL, heated)) 
• Function sequence for washing (with CODE 874 (MAGIC VISION CONTROL, heated)) 
• Afterwiping function sequence 
• Function sequence for interrupting washing during engine start 
• Function sequence for wash stop 

Function sequence for washing (without CODE 874 (MAGIC VISION CONTROL, heated)) 

The washer fluid is delivered to the spray nozzles via hoses and sprayed onto the windshield accordingly.

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 this via chassis CAN 1 (CAN E1), electronic ignition lock control unit and interior CAN to the SAM control unit.

The SAM control unit receives the request and actuates the windshield washer system pump (M5/1) directly.

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 after t = 15 s:

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

Function sequence for washing (with CODE 874 (MAGIC VISION CONTROL, heated)) 

The washer fluid is pumped through the hoses to the wiper blades and sprayed directly in front of the wiper blades in accordance with the direction in which the wiper arms are moving. In other words, when the wiper arms move upwards, only the top part of the wiper blades is supplied with washer fluid.

In other words, when the wiper arms move downwards, only the lower part of the wiper blades is supplied with washer fluid. With its low washer fluid consumption, this optimizes the windshield cleaning process while also reducing the level of wiper blade wear.

The status of the washer fluid level switch (S42) is read in by the SAM control unit. When the washer fluid level falls below the minimum level, the front SAM control unit sends the request to output a message via the interior CAN to the instrument cluster (A1). In the multifunction display (A1p13), a message and a symbol indicate that washer fluid should be refilled. The 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. A resistance measurement detects whether the washer fluid level is low.

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

The steering column tube module control unit reads in the position of the combination switch directly and forwards it via chassis CAN 1, electronic ignition lock control unit and interior CAN to the SAM control unit.

The SAM control unit receives the request and actuates the windshield washer system pump directly.

Depending on the direction in which the wiper arms are moving, only the upper or the lower side of each wiper blade is supplied with washer fluid. An algorithm in the SAM control unit is used to calculate where the wiper arm is located on the windshield and in which direction it is moving.

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 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.

On vehicles without CODE 874 (MAGIC VISION CONTROL, heated):

• Actuation time t < 200 ms: Afterwiping does not take place.
• Actuation time t < 1 s: A single afterwipe occurs.
• Actuation time t > 1 s: Three afterwipes occur.

On vehicles with CODE 874 (MAGIC VISION CONTROL, heated):

• Actuation time t < 200 ms: Afterwiping does not take place.
• Actuation time t < 2 s: A single afterwipe occurs.
• Actuation time t > 2 s: Two afterwipes occur.

The SAM control unit sends the "Afterwiping active" status via roof LIN (LIN B13) to the rain/light sensor with additional functions (B38/2).

Wiping requests from the rain/light sensor with additional functions are ignored during afterwiping.

The SAM control unit directly actuates the wiper motor (M6/1).

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
• Wiper motor blockage detection
• Activating wash function
• Activating wipe/stop function

Function sequence for interrupting washing during engine start 

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

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 sends the status of circuit 50 via interior CAN to the SAM control unit.

Function sequence for wash stop 

The wash stop function prevents the windshield washer system pump from being actuated when the engine hood is open.

The status of the engine hood is monitored by the following components that are read in directly by the SAM control unit:

• Right engine hood contact switch (S62/42)
• Left engine hood contact switch (S62/43)

If an open engine hood is recognized, the SAM control unit interrupts the windshield washer system pump actuation.

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 > 6 km/h.

The instrument cluster (A1) sends the vehicle speed information via interior CAN to the SAM control unit.

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