Function of Windshield Washer

The signal acquisition and actuation module (SAM) (N10/1) receives the CAN message indicating the position of the combination switch (S4) from the electronic ignition switch (EIS) control module (N73). The SAM switches on the windshield washer pump (M5/1) and wiper motor (M6/1) via the windshield washer relay (K40/2k3): The pump remains switched on as long as actuation of the combination switch (S4) is received via the CAN bus, however, for a maximum of 7 seconds. After releasing the switch or following the seven second delay the wiper motor (M6/1) remains switched on for 3 more seconds to wipe off the remaining water.

The wiper motor is then braked. If the combination switch (S4) is simultaneously switched to wiper stage 2, the wiper operates in stage 2 during the washing operation as well.

If the combination switch (S4) is pressed only to the pressure point, the electronic ignition switch (EIS) control module (N73) sends the CAN message for one-wipe operation instead of the CAN message to wash the windshield. The SAM then actuates only the wiper.