Windshield washer, function - GF82.35-P-3002FQ

MODEL 218 

Function requirements, general 

• Circuit 15R ON

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

Washing windshield, general 

The windshield is kept clean by washing the windshield.

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) reads in the switch position of the combination switch directly and sends this via chassis CAN (CAN E) (up to 28.2.13) or chassis CAN 1 (CAN E1) (as of 1.3.13) to the front SAM control unit. The front SAM control unit receives the request and actuates the windshield washer system pump (M5/1). During washing, wiping takes place with the wiper speed set on the combination switch.

When the combination switch is in the rest position, wiping takes place with speed "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:

• 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.

The front SAM control unit transmits the status "Afterwipe active" via the wiper/inside rearview mirror LIN (LIN 2) to the rain/light sensor (B38/2). Wiping requests from the rain/light sensor during afterwiping are ignored. 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 (M6/1)
• 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. A washer procedure 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 an open engine hood is detected by the status of the left engine hood contact switch (S62/43), the front SAM control unit deactivates actuation of the windshield washer system pump. 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 information to the front SAM control unit via the interior CAN.

The status of the left engine hood contact switch is read in by the rear SAM control unit with fuse and relay module (N10/2) directly and it sends this over the interior CAN to the front SAM control unit.

Electrical function schematic for windshield washer	PE82.35-P-2051-97XAA
Overview of system components, wiper system (WSA)	GF82.30-P-9997FQ