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.
The following components are described for the windscreen wipers:
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.
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.
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.
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.
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.
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 ground 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.
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.
The windscreen washing pump is attached to the washer fluid container. The windscreen washing pump is electrically activated by the JBE.
The washer nozzles are heated electrically. This prevents the washer nozzles freezing in cold weather. The washer-nozzles heating system consists of heating resistors. The washer nozzles are electrically activated via the JBE at an outside temperature below 3 °C.
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.
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 |
Washer fluid level switch |
Block circuit diagram R56
Index |
Explanation |
Index |
Explanation |
|---|---|---|---|
1 |
Steering Column Switch Cluster (SZL) |
2 |
Fuse and relay carrier in the engine compartment |
3 |
Front wiper motor |
4 |
Heated washer nozzle, left |
5 |
Heated washer nozzles, right |
6 |
Headlamp-washer pump |
7 |
Windshield washer pump |
8 |
Junction box electronics (JBE) |
9 |
Rear wiper motor |
10 |
Additional instrument |
11 |
Outside temperature sensor |
12 |
Rain / driving light sensor (RLS) |
13 |
Washer fluid level switch |
|
|
The following system functions are described for the windscreen wipers:
The wiper functions can be operated as of terminal R.
The following wiper functions are possible:
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).
When the low beam is switched on, the headlamps are washed every 5th time the windscreen washer is operated.
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:
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