Rear Window Wiper System, Function - GF82.30-P-2400GW

Model 463 (except 463.202)

as of model year 2013

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) (as of 03.04.2018 except model 463.342), or the SAM control unit (N10) (up to 02.04.2018 or model 463.342). The front SAM control unit (as of 03.04.2018 except model 463.342), or the SAM control unit (up to 02.04.2018 or model 463.342) is the master control unit for the rear window windshield wiper system.

Rear window wiper system, general

The rear window wiper system allows wiping and washing the rear window.

The logic for control of the rear window windshield wiper system is stored in the front SAM control unit (as of 03.04.2018 except model 463.342), or in the SAM control unit (up to 02.04.2018 or model 463.342).

An appropriate symbol appears on the multifunction display (A1p13) when the rear window wiper is switched on. To do so, the front SAM control unit (as of 03.04.2018, except model 463.342) or the SAM control unit (up to 02.04.2018 or model 463.342) sends the "rear window wiper active" status and as of 03.04.2018 except model 463.342 over the interior CAN, electronic ignition lock control unit and the user interface CAN (CAN HMI) or up to 02.04.2018 or for model 463.342 directly over the interior CAN to the instrument cluster (A1).

When a wiping function is switched off, the rear window windshield wiper is moved to the parked position.

The rear window wiper system function consists of the following subfunctions:

Intermittent wipe function sequence
Function sequence for backup wiping
Washing function sequence
Wiper start suppression function sequence

Intermittent wipe function sequence

The rear window intermittent wipe function is activated by actuating the 2nd ring on the multifunction switch (S4).

As of 03.04.2018 (except model 463.342) the steering column tube module control unit reads in the switch position of the combination switch directly and sends this over the suspension FlexRay (Flex E), electronic ignition lock control unit and the interior CAN to the front SAM control unit. The front SAM control unit evaluates the switch position of the combination switch and transmits the "Switch on rear window wiper" request (wiper speed) via the interior CAN to the rear SAM control unit (N10/8).

Up to 02.04.2018 or for model 463.342, the steering column tube module control unit reads in the switch position of the combination switch directly and sends this over suspension CAN 1 (CAN E1), the electronic ignition lock control unit and the interior CAN to the SAM control unit.

The rear SAM control unit (as of 03.04.2018 except model 463.342), or the SAM control unit (up to 02.04.2018 or model 463.342) evaluates the switch position and actuates the rear-end door wiper motor (M6/4) accordingly.

The actuation time is approx. t = 2 s (duration of a wipe cycle). This is followed by a pause of approx. t = 5 s.

Additional function requirements for backup wiping

Windshield intermittent wiping function active:
As of 03.04.2018 except model 463.342 an active windshield intermittent wipe function on the rear-end door wiper motor is actuated to match the rain sensor (B38/2b1) request in the rain and light sensor with additional functions (B38/2). The front SAM control unit reads in the status of the rain and light sensor with additional functions over the rain and light sensor LIN (LIN B16).

Up to 02.04.2018 or for model 463.342, for an active windshield intermittent wiping function of the rear-end door wiper motor, the rain and light sensor (B38/2) request is then actuated. The SAM control unit reads in the status of the rain and light sensor with additional functions over the roof LIN (LIN B13).

Function sequence for backup wiping

When the windshield intermittent wipe function is activated, the backup wipe function is activated automatically when the vehicle is shifted into reverse gear.

The rear-end door wiper motor is actuated in accordance with the position of the multifunction switch:

With interval 1 or interval 2:
- The rear window wiper runs synchronously with the windshield wiper.
With continuous wipe 1 or continuous wipe 2:
- The rear window wiper wipes in continuous wipe mode, but not synchronously with the windshield wiper.

The steering column tube module control unit reads in the switch position of the combination switch directly and sends it as of 03.04.2018 except model 463.342 over the suspension FlexRay or up to 02.04.2018 or for model 463.342 over suspension CAN 1, the electronic ignition lock control unit and the interior CAN to the front SAM control unit (as of 03.04.2018 except model 463.342), or the SAM control unit (up to 02.04.2018 or model 463.342).

"Reverse gear engaged" status is defined via the engaged gear range.

As of 03.04.2018 and except model 463.342:

The fully integrated transmission control unit (Y3/8n4) sends the engaged drive range over the drive CAN (CAN C1), powertrain control unit (N127) and the suspension FlexRay to the electronic ignition lock control unit.

The electronic ignition lock control unit generates the "reverse gear engaged" signal and sends this over the interior CAN to the front SAM control unit. The front SAM control unit evaluates the status and sends the request "Switch on rear window wiper" via interior CAN to the rear SAM control unit. The rear SAM control unit then actuates the rear-end door wiper motor accordingly.

Up to 02.04.2018 or for model 463.342:

The fully integrated transmission control unit sends the engaged drive range over the drive CAN (CAN C), CDI control unit (N3/9) (engine 642) or the ME-SFI [ME] control unit (N3/10) (engine 157, 273) and suspension CAN 1 to the electronic ignition lock control unit.

On model 176, the fully integrated transmission control unit sends the engaged gear range via the drive train CAN, the powertrain control unit and chassis CAN 1 to the electronic ignition lock control unit.

The electronic ignition lock control unit generates the "Reverse gear engaged" signal and transmits this via the interior CAN to the SAM control unit, which then actuates the rear-end door wiper motor accordingly.

Additional function requirements for wash

Windshield wash not active

Washing function sequence

By actuating the 2nd ring on the combination switch, the rear window wash function is activated.

As long as the request is pending (maximum t = 15 s) the front SAM control unit (as of 03.04.2018 except model 463.342) or the SAM control unit (up to 02.04.2018 or model 463.342) actuates the windshield washer system pump (M5/1). The rear-end door wiper motor is only actuated after a short delay.

If the request is no longer present, actuation of the windshield washer system pump stops immediately. Actuation of the rear-end door wiper motor ends after two afterwipe cycles.

If a request is only present for a short time, only one afterwipe cycle takes place.

Additional function requirements for wiper start suppression

Vehicle speed v < 3 km/h
Combination switch (2nd ring) in interval setting or
reverse gear wiping active

Wiper start suppression function sequence

If, during a wipe procedure, a door or the rear-end door is opened, the front SAM control unit (as of 03.04.2018 except model 463.342) or the SAM control unit (up to 02.04.2018 or model 463.342) interrupts actuation of the rear-end door wiper motor.

The instrument cluster sends the vehicle speed as of 03.04.2018 and except model 463.342 over the user interface CAN, electronic ignition lock control unit and the interior CAN to the front SAM control unit (as of 03.04.2018, except model 463.342) or up to 02.04.2018 or for model 463.342 directly over the interior CAN to the SAM control unit (up to 02.04.2018 or model 463.342).

The opening of the left front door is recognized by the status of the left front door rotary tumbler switch (A85s1) in the left front door lock (A85). The left front door control unit (N69/1) reads in the status of the left front door rotary tumbler switch directly and sends this over the interior CAN to the front SAM control unit (as of 03.04.2018, except model 463.342), or the SAM control unit (up to 02.04.2018 or model 463.342).

The opening of the right front door is recognized by the status of the right front door rotary tumbler switch (A85/1s1) in the right front door lock (A85/1). The right front door control unit (N69/2) reads in the status of the right front door rotary tumbler switch directly and sends this over the interior CAN to the front SAM control unit (as of 03.04.2018, except model 463.342), or the SAM control unit (up to 02.04.2018 or model 463.342).

An opened rear-end door is recognized by the status of the rear-end door rotary tumbler switch (S17/18). The rear SAM control unit (as of 03.04.2018, except model 463.342), (N10/8) or the rear passenger compartment control unit (up to 02.04.2018 or model 463.342) (N10/8) reads in the status of the rear-end door rotary tumbler switch directly and sends this over the interior CAN to the front SAM control unit (as of 03.04.2018, except model 463.342), or the SAM control unit (up to 02.04.2018 or model 463.342).

The front SAM control unit (as of 03.04.2018, except model 463.342), or the SAM control unit (up to 02.04.2018 or model 463.342) reads in all relevant information, evaluates it and interrupts actuation of the rear-end door wiper motor.

The rear-end door wiper motor is actuated again after wiper startup suppression has been deactivated by one of the following events:

Vehicle speed v > 3 km/h
Rear wipe request
Rear wash request
Rotary tumbler switch closed and selector lever in position "D" or "R"
Rotary tumbler switch closed and change from circuit 15C to circuit 15R

Electrical function schematic for rear window wiper system	Model 463 (except 463.202/342) as of model year 2019	PE82.30-P-2056-97ZGB
	Model 463 (except 463.202/342) as of model year 2013 up to model year 2019Model 463.342 as of model year 2017	PE82.30-P-2056-97ZGA
Overview of system components for windshield wiper system		GF82.30-P-9996GW