Windscreen Wipers

Windscreen Wipers

Windscreen wipers
All windscreen wiper functions in the E70 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
- Steering column switch cluster (SZL)
- Dynamic Stability Control (DSC)
- Junction box electronics (JBE)
- Rain/light solar sensor (RLSS)
- Roof control panel
- Instrument cluster
- Front wiper motor
- Rear wiper motor
- Windscreen washing pumps
- Washer jet
- Headlight-cleaning system

Wiper switch
The wiper switch is operated with one touch. The wiper switch does not lock into place. The wiper switch sends its signals to the steering column switch cluster (SZL).

Steering column switch cluster (SZL)
The SZL forms the interface between the wiper switch and the junction box electronics (JBE). The signals from the wiper switch are processed by the SZL and forwarded to the Dynamic Stability Control (DSC). The SZL sends its information via the F-CAN to the DSC.

Dynamic Stability Control (DSC)
The DSC processes the information from the SZL. The DSC forwards the requests from the SZL and the information regarding driving speed to the junction box electronics (JBE). The DSC is connected to the JBE via the PT-CAN.

Junction box electronics (JBE)
The JBE processes the information from the DSC and the roof function centre (FZD). The JBE controls the load switching for the wiper motors and windscreen washing pumps. The load switching of the wiper motors takes place via internal relays. The washer fluid level switch sends its information to the JBE.

Rain/light solar sensor (RLSS)
On vehicles with a rain/light solar sensor (RLSS), this handles the automatic intermittent control. The rain/light solar sensor (RLSS) is fitted in the mirror base on the windscreen. This means that wiper operation depends on the rain intensity and driving speed. The RLSS sends its request, e.g. wipe, to the roof function centre (FZD). In the case of equipment without RLSS, is the interval for windscreen wiper operation is specified.

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

Roof control panel
The FZD receives the message from the RLSS. The FZD forwards the message 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 internal 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 pumps
The windscreen washing pumps for the front and rear are attached to the washer fluid container. The windscreen washing pumps are 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 heated 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 or intensive cleaning is activated. Switching off terminal R resets the repeat lock-out and the counter for wash operations.












System functions
The following system functions are described for the windscreen wipers:
- Wipe functions
- Wash functions
- Headlight washer
- Safety functions

Wipe functions
The wiper functions can be operated as of terminal R.
The following wiper functions are possible:
- Flick wipe
- Intermittent wipe
- Wiper speed 1
- Wiper speed 2
- Automatic wiping

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:
- approx. three minutes have elapsed
- Terminal R OFF followed by Terminal R ON

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