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

Model 217, 222

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 front SAM control unit (N10/6).

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:

Intermittent wipe function sequence
Wiper start suppression function sequence
Function sequence of wiping at specified speed
Single wipe function sequence
Function sequence for interrupting wiping during engine start
Automatic speed reduction function sequence (without CODE 494 (USA version))
Function sequence for wipe stop

Intermittent wipe function sequence

The intermittent wipe function is activated by turning the combination switch (S4) to position "1" (rain sensor (B38/2b1) with low sensitivity) or to position "2" (rain sensor with high sensitivity).

When changing the switch position of the combination switch from switch position "0" to "1" or "2" or when changing from switch position "1" to "2", a wipe cycle ("reaction wipe") is activated.

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 sends the switch position of the combination switch via the rain/light sensor LIN (LIN B16) to the rain sensor in the rain/light sensor with additional functions (B38/2).

Based on the position of the combination switch and the degree of wetness of the windshield, the rain sensor calculates the frequency of the required wiping cycles and sends a corresponding request back to the front SAM control unit via the rain/light sensor LIN.

The front SAM control unit then actuates the wiper motor (M6/1) over the rain/light sensor LIN correspondingly.

The intermittent wipe function is interrupted under the following conditions:

Activating wipe/stop function
Activating wash function
Activating single wipe function
Activation of afterwipe function
Activating wiper startup suppression function
Turning combination switch to position "0", "3" or "4"
Blocking wiper motor
Missing or faulty rain sensor data

Additional function requirements for wiper start suppression

Vehicle speed v < 3 km/h
Combination switch in position "1" or "2"

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 of the vehicle 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.

To do this, the following variables are taken into account:

Vehicle speed
Switch position of the combination switch
Status of doors

Vehicle speed:

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.

Switch position of the combination switch:

Status of doors:

The left front door control unit (N69/1) sends the status of the left front door over interior CAN to the front SAM control unit. The right front door control unit (N69/2) sends the status of the right front door over interior CAN to the front SAM control unit.

The front SAM control unit reads in all relevant information, evaluates it and interrupts actuation of the wiper motor. A wiping procedure that has already started 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 front passenger door closed and gear range "D" or "R" engaged

With circuit 15R On, no information on the current gear range is sent to the front SAM control unit by the fully integrated transmission control unit (Y3/8n4) over the drive train CAN (CAN C1), powertrain control unit (N127), chassis FlexRay, electronic ignition lock control unit and interior CAN. Instead, "Gear range N" is constantly sent. The current gear range is only available as of circuit 15 On. The wiper startup suppression function is not canceled by circuit 15R On through the status of the gear range.

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 steering column tube module control unit reads in the switch position of the combination switch directly and sends it via chassis FlexRay, the electronic ignition lock control unit and interior CAN to the front SAM control unit. The front SAM control unit then actuates the wiper motor over the rain/light sensor LIN correspondingly.

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

Activating wipe/stop function
Activating wash function
Activation of afterwipe function
Activation of speed reduction function (without 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.

Wipe once:

To wipe once, briefly push the combination switch axially 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.

The front SAM control unit then actuates the wiper motor over the rain/light sensor LIN correspondingly.

If the combination switch is held in switch position "0" for longer than t = 30 s, a "stuck combination switch" is assumed and the single wipe function is interrupted despite the current 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

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.

Additional function requirements for automatic speed reduction (without CODE 494 (USA version))

Combination switch in position "3" or "4"
Vehicle speed reduction from v > 6 km/h to v < 3 km/h

Automatic speed reduction function sequence (without CODE 494 (USA version))

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

For this reason, the front SAM control unit reduces the wiper speed as soon as vehicle deceleration from v > 6 km/h to v < 3 km/h is detected.

The instrument cluster 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.

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

Additional function requirements for wipe stop

Wipe or wash function activated

Function sequence for wipe stop

The wipe stop function prevents the wiper motor from being actuated by the front SAM control unit when the engine hood is open and thus causing damage to the vehicle. If the engine hood is opened at a speed of v < 3 km/h, the front SAM control unit immediately stops the wiper motor actuation. At a speed of v > 6 km/h, the wiper stop function is deactivated, i.e. the wiper motor is actuated again from this speed onwards.

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

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

The instrument cluster 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.

The front SAM control unit reads in all relevant information, evaluates it and interrupts actuation of the wiper motor via the rain/light sensor LIN.

	Electrical function schematic for windshield wiper		PE82.30-P-2051-97SEA
	Overview of system components for windshield wiper system		GF82.30-P-9996LF