All wipe/wash functions can be switched on with the wiper switch as of terminal R (ignition lock in position 1).
The wiper switch can be switched to intermittent wipe, stage 1 and stage 2. These settings are coded by means of two lines leading to the general module. They are each switched to ground
On vehicles equipped with the special option automatic interval control (AIC), in the "intermittent" switch position, the intermittent wipe function is controlled by a rain sensor (refer to functional description for automatic interval control).
A knurled wheel with a potentiometer is integrated in the wiper switch. This makes it possible to set four different intervals. These times are also controlled according to road speed. The faster the vehicle is driven, the shorter the interval.
On vehicles equipped with automatic interval control (AIC), the sensitivity of the rain sensor can be influenced with the thumbwheel.
The wiper motor is configured for two different wiper speeds. The load is switched via two external relays.
The end position (park position) of the wiper motor is recognized by means of a reset contact integrated in the motor. This contact switches ground to the general module when the motor has reached its end position.
The reset contact is also used for monitoring the wiper motor. If the contact signal is not received for 16 seconds with the wiper motor switched on (e.g. dry running), the wiper motor is switched off in order to protect it from overloading.
The wiper is not switched on again before it has been switched off and a lock-out time of 3 minutes has elapsed.
The wiper speed is set at the wiper switch. If automatic interval control is not installed, the wiper speed will be additionally controlled according to the road speed. The following settings apply:
Road speed |
Switch set to stage 1 |
Switch set to stage 2 |
|---|---|---|
< 6 km/h |
Intermittent wipe |
Wiper motor at stage 1 |
> 6 km/h |
Wiper motor at stage 1 |
Wiper motor at stage 2 |
When stage 2 is switched on, stage 1 cuts in at > 205 km/h to prevent the wiper arm from lifting.
On vehicles with the optional extra automatic interval control (AIC), the windscreen wipers are not controlled according to road speed.
The drive for the headlight washer pump is actuated via an external relay.
The headlight wash function is triggered every fifth time wash or intensive wash is activated when the headlight or parking lights are switched on. The headlights are sprayed twice.
The headlight wash function is blocked for 3 minutes at the end of a wash cycle.
Switching off terminal R resets the repeat lock-out and the counter for wash operations. When terminal R is switched on again with the lights on, the headlight wash function can be activated immediately.