Windshield Wiper, Function - GF82.30-P-3004RD

Model 172.4

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).

Wiping windshield, general

The windshield wiping function keeps the windshield free of water or snow, for example.

The windshield wiper function is comprised of the following subfunctions:

Reaction wiping function sequence
Function sequence for interrupting wiping during engine start
Intermittent wipe function sequence
Function sequence of wiping at specified speed
Single wipe function sequence
Wiper start suppression function sequence
Function sequence for wipe stop (with code 551 (Anti-theft alarm system (ATA [EDW]))
Function sequence for automatic speed reduction (except CODE 494 (USA version))

Reaction wiping function sequence

The reaction wipe function is activated by turning the multifunction switch (S4) to an intermittent wipe stage.

The steering column tube module control unit (N80) directly reads in the switch position of the combination switch and sends it via chassis CAN 1 (CAN E1) as of 01.03.2016 and via chassis CAN (CAN E) up to 29.02.2016 to the front SAM control unit. The front SAM control unit then actuates the wiper motor (M6/1) through the wiper/inside rearview mirror LIN (LIN 2).

The reaction wiping function is immediately interrupted under the following conditions:

Activation of the windshield wash function
Activating single wipe function
Wipe stop function activation through left engine hood contact switch (S62/43) (as of 01.06.2015 or except code U60 (Active engine hood (pedestrian protection)) up to 31.05.2015) or through the pedestrian protection Hall sensor + engine hood ATA [EDW] switch (A38/1) (with code U60 (Active engine hood (pedestrian protection)) up to 31.05.2015)

The reaction wiping function is also canceled if blockage of the wiper motor is detected.

The rear SAM control unit with fuse and relay module (N10/2) reads in the status of the left engine hood contact switch (as of 01.06.2015 or except code U60 (Active engine hood (pedestrian protection)) up to 31.05.2015) or the status of the pedestrian protection Hall sensor + engine hood ATA [EDW] switch (with code U60 (Active engine hood (pedestrian protection)) up to 31.05.2015) and sends it via interior CAN to the front SAM control unit.

Function sequence for interrupting wiping during engine start

During engine start, the front SAM control inhibits the actuation of the wiper motor.

Any wiping 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.

Intermittent wipe function sequence

By turning the combination switch to position "1" (wiping with a longer interval time) or to position "2" (wiping with a shorter interval time), the intermittent wipe function is switched on.

The steering column tube module control unit directly reads in the switch position of the combination switch and sends it via chassis CAN 1 as of 01.03.2016 and via chassis CAN up to 29.02.2016 to the front SAM control unit. The front SAM control unit actuates the wiper motor accordingly.

The time interval for a wipe procedure on vehicles except CODE 345 (Windshield wiper with rain sensor) is defined as a function of the switch position of the combination switch.

On vehicles with CODE 345 (Windshield wiper with rain sensor), the rain/light sensor (B38/2) calculates the frequency of the required wipe actions depending on the switch position of the multifunction switch and the quantity of moisture on the windshield.

The front SAM control unit sends the switch position of the combination switch via wiper/inside rear-view mirror LIN to the rain/light sensor. This then calculates the frequency of the required wipe operations and sends the corresponding requests back to the front SAM control unit.

The front SAM control unit actuates the wiper motor accordingly. Depending on requirements, the wipe speed is dynamically increased up to continuous wipe at high speed (maximum wipe speed).

The intermittent wipe function is interrupted under the following conditions:

Activating wipe/stop function
Activating wash function
Activating touch wipe, afterwipe or reaction wipe function
Activating wiper startup suppression function
Turning combination switch to position "0", "3" or "4"
Blocking wiper motor
Faulty or defective data for rain/light sensor

Function sequence of wiping at specified speed

The wipe function with predefined speed is activated by turning the multifunction switch to position "3" (continuous wipe at low speed) or position "4" (continuous wipe at high speed).

The wash function with predefined speed is interrupted under the following conditions:

Activating wipe/stop function
Activating wash function
Activation of afterwipe function
Activating the speed reduction function (not in vehicles with code 494 (USA version))
Turning the combination switch to position "0", "1", or "2"
Blocking wiper motor

Single wipe function sequence

The single wipe function can only be activated if the combination switch is set to position "0", "1" or "2". If the windshield wiper is not located in the rest position, the request of the combination switch is ignored.

The single wipe function is activated by pressing the combination switch up to the detent point.

Single wipe:
To wipe once, briefly push the combination switch to the detent point.
Repeated wiping:
If the combination switch is pressed for longer, wiping takes place in accordance with the duration for which it is pressed, but only for a maximum of t = 30 s.

If the combination switch is pressed and held in the "0" position for longer than t = 30 s, the front SAM control unit judges this to be a "stuck combination switch" and interrupts the single wipe function despite a pending request.

The speed at which the windshield wiper is moved during single wipe corresponds to the wiping speed in position "3" (continuous wipe at low speed).

The single wipe function is interrupted under the following conditions:

Activating wash function
Activation of afterwipe function
Activating wipe interruption during engine start function
Blocking wiper motor

Additional function requirements for wiper start suppression

Vehicle speed v < 3 km/h
Combination switch in position "1" or "2"
Rain/light sensor (with code 345 (Windshield wiper with rain sensor)) detects a wet windshield

The electronic ignition lock control unit sends the circuit status circuit 15R via the interior CAN to the front SAM control unit.

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

The steering column tube module control unit reads in the switch position of the combination switch and sends it via chassis CAN 1 as of 01.03.2016 and via chassis CAN up to 29.02.2016 to the front SAM control unit.

The rain/light sensor data is read by the front SAM control unit via the wiper/inside rear-view mirror LIN.

Wiper start suppression function sequence

The wiper start suppression is intended to prevent the driver or front passenger from being sprayed with water from the windshield when getting in or out as the result of an initiated wipe operation. The windshield wipers remain in the park position despite a wipe request triggered manually or automatically.

If a door is opened during wiping, the front SAM control unit interrupts the actuation of the wiper motor via wiper/inside rearview mirror LIN.

Opening the left door is recognized by the status of the left door lock rotary tumbler switch (A85s1) which is read in by the left door control unit (N69/1).

Opening the right door is recognized by the status of the right door lock rotary tumbler switch (A85/1s1) which is read in by the right door control unit (N69/2).

The front SAM control unit reads in all relevant information, evaluates it and interrupts actuation of the wiper motor. An already started wiping procedure is not interrupted immediately. The wipers continue to move to the park position.

The wiper start suppression is deactivated under the following circumstances:

Vehicle speed v ≥ 3 km/h
Combination switch in position "3" or "4"
Single wipe or wash function activated
Driver and passenger door closed
Transmission selector lever in position "D" or "R" (with transmission 722.9, 725.0)
Clutch operation (with transmission 711, 716)
Change from circuit 15C to circuit 15R

At circuit 15R On, no information on the current selector lever position is sent; the "Selector lever position N" is constantly sent instead. The current selector lever position is only available as of circuit 15 On. The wiper startup suppression function is not canceled by the selector lever position with circuit 15R On.

The electronic selector lever module control unit (N15/5) (with transmission 722.9) or the DIRECT SELECT INTERFACE (N150) (with transmission 725.0) sends the status of the selector lever position via drive train CAN (CAN C), CDI control unit (N3/9) (with diesel engine) or ME-SFI [ME] control unit (N3/10) (with gasoline engine) and chassis CAN 1 (as of 01.03.2016) or chassis CAN (up to 29.02.2016) to the front SAM control unit.

The "Clutch operated" status (with transmission 711.6, 716.7) is recorded by the clutch pedal switch (S40/3). The CDI control unit or the ME-SFI [ME] control unit reads in the status of the clutch pedal switch and sends it via chassis CAN 1 as of 01.03.2016 and via chassis CAN up to 29.02.2016 to the front SAM control unit.

Additional function requirements for wipe stop (with code 551 (Anti-theft alarm system (ATA [EDW]))

Wipe or wash function activated

Function sequence for wipe stop (with code 551 (Anti-theft alarm system (ATA [EDW]))

The wipe stop function prevents the wiper motor from being actuated with the engine hood open.

If, at a speed of v < 3 km/h, the left engine hood contact switch (as of 01.06.2015 or except code U60 (Active engine hood (pedestrian protection)) up to 31.05.2015) or the pedestrian protection Hall sensor + engine hood ATA [EDW] switch (with code U60 (Active engine hood (pedestrian protection)) up to 31.05.2015) detects an open engine hood, the corresponding wipe function is immediately stopped.

The rear SAM control unit with fuse and relay module sends the status of the left engine hood contact switch (as of 01.06.2015 or except code U60 (Active engine hood (pedestrian protection)) up to 31.05.2015) or the status of the pedestrian protection Hall sensor + engine hood ATA [EDW] switch (with code U60 (Active engine hood (pedestrian protection)) up to 31.05.2015) via interior CAN to the front SAM control unit. The instrument cluster sends the vehicle speed via chassis CAN 2 (CAN E2) as of 01.03.2016 and via interior CAN up to 29.02.2016 to the front SAM control unit.

The front SAM control unit reads in all relevant information and interrupts wiper motor actuation.

The wipe stop function is interrupted at a speed of v > 6 km/h, i.e. the wiper motor is actuated as from this speed again.

Additional function requirements for automatic speed reduction (except CODE 494 (USA version))

Combination switch in position "3" or "4"
Reduction on vehicle speed from v > 6 to v < 3 km/h

Function sequence for automatic speed reduction (except CODE 494 (USA version))

It is assumed that the windshield does not become as wet at slow speeds.

This is why the front SAM control unit activates the automatic speed reduction function for the windshield wiper system.

When the vehicle speed is reduced from v > 6 to v < 3 km/h, the front SAM control unit switches the wiper motor speed back by one stage via wiper/inside rearview mirror LIN.

The instrument cluster sends the vehicle speed via chassis CAN 2 as of 01.03.2016 and via interior CAN up to 29.02.2016 to the front SAM control unit.

The front SAM control unit reads in all relevant information and switches the wiping speed of the wiper motor one stage down.

The automatic speed reduction function of the windshield wiper system is interrupted under the following conditions:

Activating single wipe function
Activating wash function

Electrical function schematic for windshield wiper	Model 172.4 as of model year 2017	PE82.30-P-2051-97TAB
	Model 172.4 up to model year 2017	PE82.30-P-2051-97TAA
Overview of system components for windshield wiper system		GF82.30-P-9996RD