Wiper and Washer Systems: Description and Operation
Windscreen Wiper Control (SWS/ZKE):General Block Diagram:
Notes:
These Instructions apply only when a ZKE general module is Installed.
Functional Description:
The windscreen wiper and washer system is controlled by the general module (GM) of the central body electronics (ZKE). The individual functions can be switched on and oft with the combined wiper/washer switch. The ignition switch must be set in position 1 or 2 (R or 15) for this purpose.
The wiper functions intermittent wipe and stage 1 are additionally dependent on the vehicle speed.
Wipe/wash Functions:
General: Ground is switched to the general module in all wipe/wash positions.
The wiper blades are returned to their park position by means of a micro-switch which is installed in the wiper motor. This switch switches ground to the general module provided the wiper is outside the park position.
Single wipe: Press down the wiper/washer switch. The switch does not lock in position. The wiper motor operates in stage 1 for as long as the wiper switch is held in this position.
Intermittent wipe: Pull up wiper/washer switch to the first position. The switch locks in position. The wiper operates in intermittent mode. The intermittent wipe cycle time depends upon the vehicle speed.
Speed: Intermittent wipe cycle time:
0-5km/h 14 seconds
5-30km/h 8 seconds
30-70 km/h 7 seconds
70-100km/h 6 seconds
100-140 km/h 5 seconds
above 140 km/h 4 seconds
Example: The wipe function is activated once every 7 seconds at a vehicle speed of 50 km/h.
The intermittent wipe cycle time can also be freely programmed. Procedure: Switch oft wiper -> briefly switch on intermittent wipe function and immediately switch oft again -> the time counter now begins to run -> wait at least 2 seconds (1 second if vehicle driving) -> switch on intermittent wipe function once again -> the time from switching oft the intermittent wipe function up to switching it on again is stored as the intermittent wipe time cycle. This time is retained until the wiper is switched oft.
The programmed intermittent wipe cycle time is doubled when the vehicle is stationary.
Wipe function in stage 1: Pull the wipe/washer switch up to the second position. The switch locks in position. When the vehicle is stationary, the wiper operates in intermittent mode. The wiper operates continuously in stage 1 at a vehicle speed in excess of 5 km/h.
Wipe function in stage 2: Pull wiper/washer switch up to third position. The switch locks in position. The wiper operates in stage 2 irrespective of the vehicle speed.
Wash function: Pull wiper/washer switch towards driver. Switch does not lock in position. The wash function is performed by the general module of the ZKE.
Wash sequence: Wash pump operates -> the wiper starts after a delay in stage 1 -> wash pump stops -> wiper continues running and wipes the windscreen dry.
The wash pump operates for as long as the switch is operated.
Intensive wash: - Optional Extra - Operate rocker switch on front end. The "intensive wash" function is controlled by the general module of the ZKE.
Procedure: Intensive wash pump operates, a special intensive wash fluid is applied to windscreen => wiper starts time-delayed in stage 1 => intensive wash pump stops => wash pump starts up => wash pump stops => wiper continues to operate and wipes the windscreen dry.
Note: If an intensive wash system is installed, the pumps for wash and intensive wash are switched via a switchover relay (installation location: front power distribution box). If no intensive wash system is installed, the wash pump is switched without a relay.
Important!
Stage 2: The ZKE general module is bypassed in wiper stage 2. Wiper operation is therefore possible in stage 2 (emergency operation) even in the case of failure of the electronic system or when the anti-blocking function is active. In this case, however, the wiper does not return automatically to the park position.
Anti-blocking function: The signal of the reset contact is used for monitoring operation of the wiper motor. The anti-blocking function is activated if the contact constantly switches ground for 30 seconds. Reasons for this could be mechanical stiffness of the wiper or breaks in the wiring. With the exception of stage 2, all wiper functions are blocked when the anti blocking function is active. The wiper does not return to the parked-position.
Clearing the anti-blocking function:
Up to 10 times in succession by switching off the wiper for approx. 3 minutes
or
by switching off the wiper and ignition for approx. 3 minutes.