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

Model 190 

Function requirements, general 

• Circuit 15R On:

  The electronic ignition lock control unit (N73) transmits the circuit 15 status to the front SAM control unit with fuse and relay module (N10/1) over the interior CAN (CAN B).

Washing windshield, general 

The windshield washing function permits cleaning the windshield with washer fluid.

The windshield wash function is comprised of the following subfunctions:

• Washing function sequence 
• Extended wiping 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 the axial direction beyond the detent point.

The steering column tube module control unit (N80) reads in the switch position of the combination switch directly and transmits this up to 30.11.2018 via suspension CAN 1 (CAN E1) and as of 01.12.2018 via the AMG FlexRay (Flex AMG), the AMG gateway control unit (N93/9) and suspension CAN 1 to the front SAM control unit.

The front SAM control unit then directly actuates the windshield washer system pump (M5/1) and simultaneously the master wiper motor (M6/6) via wiper/inside rearview mirror LIN (LIN 2). The master wiper motor actuates the slave wiper motor (M6/7) accordingly.

During washing, wiping takes place with the wiper speed set on the combination switch or, with the combination switch in the rest position, 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

Extended wiping function sequence 

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

The rain/light sensor (B38/2) detects the degree of wetness of the windshield. The rain/light sensor then calculates the frequency of the required wiping cycles based on the switch position of the combination switch and sends the corresponding wipe request to the front SAM control unit via wiper/inside rearview mirror LIN.

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.

Detailed information on the wipe request of the rain/light sensor can be found in the subfunction "Windshield wipe, function".

Extended wiping takes place with the wiper speed set on the combination switch. When the combination switch is in the rest position, extended wiping takes place with speed "3".

The extended wiping function is interrupted or aborted under the following conditions:

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

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.

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 

If the engine hood is opened while the windshield is being washed, the front SAM control unit aborts the actuation of the windshield washer system pump. The opening of the engine hood is detected by the right engine hood contact switch (S62/42). The front SAM control unit directly reads in the status of the right 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) transmits the vehicle speed to the front SAM control unit via the user interface CAN (CAN HMI), AMG gateway control unit and the interior CAN.

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