Windscreen wipers

Windscreen wipers

All windscreen wiper functions in the R56 can be operated with the wiper switch as of terminal R On. The windscreen wipers are driven by an electric motor with a reduction gear.

Brief description of components

The following components are described for the windscreen wipers:

Wiper switch

The wiper switch is operated with one touch. The wiper switch does not lock into place. Wiping the rear window is switched on by turning the cap on the wiper switch.

Steering column switch cluster (SZL)

The SZL forms the interface between the wiper switch and the junction box electronics (JBE). The signals from the SZL are forwarded via the PT-CAN to the JBE.

Junction box electronics (JBE)

The JBE processes the signals from the SZL and the driving speed. The JBE controls the load switching for the wiper motors. The load switch from the front wiper motor takes place via two external relays. These external relays are located on the fuse and relay carrier in the engine compartment. The JBE electrically activates the windscreen washing pump and the headlight-cleaning system. The washer fluid level switch sends its information to the JBE.

Rain / driving light sensor (RLS)

On vehicles with a rain / driving light sensor (RLS), this handles the automatic intermittent control. The rain / driving light sensor is fitted in the mirror base on the windscreen. This means that wiper operation depends on the rain intensity. The RLS sends its request, e.g. wipe, via the LIN bus to the JBE. The JBE is responsible for power supply to the RLS. In the case of equipment without RLS, is the interval for windscreen wiper operation is specified.

Additional instrument

The additional instrument receives information on the outside temperature from the outdoor temperature sensor. The additional instrument forwards the information on the K-CAN to the JBE.

Front wiper motor

The wiper motor is a rotary motor without electronic modules. The wiper motor is configured for two different wiper speeds. The wiper motor is activated via two external relays. The wiper motor's end position (off position) is detected by a reset contact integrated in the wiper motor. The reset contact switches earth to the JBE as soon as the wiper motor has reached the end position (rest position). The reset contact is also used for monitoring the wiper motor.

Rear wiper motor

The rear wiper motor has the same structure as the front wiper motor. The rear wiper motor is electrically activated via an integrated relay in the JBE.

Windscreen washing pump

The windscreen washing pump is attached to the washer fluid container. The windscreen washing pump is electrically activated by the JBE.

Washer jets

The washer jets are heated electrically. This prevents the washer jets freezing in cold weather. The washer-jet heating system consists of heating resistors. The washer jets are electrically activated via the JBE at an outside temperature below 3 °C.

Headlight washer

The headlight-cleaning system is offered as an optional extra. The JBE handles activation of the washer pump for the headlight-cleaning system. Headlight cleaning only takes place when the low-beam headlight is switched on. The headlight cleaning is activated every 5th time the washing is activated. Switching off terminal R resets the repeat lock-out and the counter for wash operations.

 

GR_FB6107044

The graphic shows the R56

Index

Explanation

Index

Explanation

1

Washer fluid container

2

Headlamp-washer pump

3

Windscreen washing pump for windscreen and rear-window washing

4

Windscreen wash fluid-level switch

 

GR_FB6107031

Block circuit diagram R56

Index

Explanation

Index

Explanation

1

Steering Column Switch (SZL)

2

Fuse and relay carrier in the engine compartment

3

Front wiper motor

4

Heated washer jet, left

5

Heated washer jet, right

6

Headlamp-washer pump

7

Windscreen washing pump

8

Junction box electronics (JBE)

9

Rear wiper motor

10

Additional instrument

11

Outside temperature sensor

12

Rain / driving light sensor (RLS)

13

Windscreen wash fluid-level switch

 

 

 

System functions

The following system functions are described for the windscreen wipers:

Wipe functions

The wiper functions can be operated as of terminal R.
The following wiper functions are possible:

Wash functions

The windscreen-washer functions are available as soon as Terminal R status is ON. To operate the windscreen washer, the wiper switch is pulled backwards (towards driver). To wash the rear window, the wiper switch must be pushed forwards (away from the driver).

Headlight washer

When the dipped headlights are switched on, the headlamps are washed every 5th time the windscreen washer is operated.

Safety functions

If the wiper motor is switched on and the signal from the reset contact is not detected for approx. 16 seconds, the wiper motor is switched off to protect against overload. It is only possible to switch the wiper motor on again after:

No liability can be accepted for printing or other errors. Subject to changes of a technical nature