The windscreen wiper functions are controlled by the general module V of the central body electronics (ZKE).
All wiper functions are active as from ignition lock position 1 (terminal R).
Wiper stages "1" and "2" are controlled depending on the vehicle speed.
Road speed |
Switch set to stage 1 |
Switch set to stage 2 |
|---|---|---|
< 4 km/h |
Intermittent wipe |
Wiper motor at stage 1 |
> 4 km/h |
Wiper motor at stage 1 |
Wiper motor at stage 2 |
When stage 2 is switched on, stage 1 cuts in at > 210 km/h to prevent the wiper arm from lifting.
Intermittent wipe is activated in the first setting of the wiper switch. The intermittent wipe time can be set by means of a rotary switch on the wiper switch in four stages. The intermittent wipe time is also influenced by the driving speed.
The wiper switch can be switched to the positions:
These positions are transferred via two lines to the general module V.
Line SW 1 |
Line SW 2 |
Function |
0 |
0 |
Rest position, wiper OFF |
1 |
0 |
Intermittent wipe |
0 |
1 |
Wiper stage 1 |
1 |
1 |
Wiper stage 2 |
A potentiometer in the form of a rotary is built into the wiper switch to vary the setting of the intermittent wipe interval. The rotary switch can be set in four stages. Based on different resistance values. The general module V can detect the switch position and thus the preselected intermittent wipe time.
Resistance |
Switch position |
Intermittent wipe time(depending on driving speed 0 - 150 km/h) |
2 kOhm |
Position 1 |
25 to 13 seconds |
4 kOhm |
Position 2 |
17 to 7 seconds |
6 kOhm |
Position 3 |
10 to 3 seconds |
8 kOhm |
Position 4 |
5 to 2 seconds |
The wiper motor is designed for two speed stages. It is powered via an external twin relay.
The output WI 1 (signal name) at the general module switches on the wiper. The output WI 2 (signal name) switches the wiper motor to stage 2.
The reset contact in the wiper motor serves the purpose of detecting the wiper rest position. The contact is designed as a slip ring.
The signals from the wiper reset contact are used to detect possible blocking of the windscreen wiper motor.
The wiper motor is switched off immediately if there is no feedback from the reset contact for 16 seconds with the wiper motor switched on (e.g. to prevent dry running).
The wiper motor is switched on again after a waiting time of 3 minutes or after terminal R off.
However, the wiper motor is not switched on automatically even if the wiper switch remains on (risk of injury) but rather only after the wiper switch has been switched off and then on again.
Jamming protection is active in all wiper stages!