Wiper Control Module: Description and Operation

1992 4 DOOR, (<9/91 PRODUCTION) - WWM CONTROL

The windshield wiping/washing system on the E36 is controlled by a separate wiper module (WWM). The system has evolved through the model years but has never been directly controlled by either the ZVM or ZKE even though it is a body electrical system.

VEHICLE INTRODUCTION TO 9/91 PRODUCTION
There are four wiping stages (speeds):
- Single wipe (pulse)
- Intermittent
- Stage 1 (slow)
- Stage 2 (fast)

Single wipe: one complete sweep of the wipers is carried out when the switch is moved into the single wipe position and released.

Intermittent: the interval time of the wipers is vehicle speed dependent. As the vehicle speed increases, wiping interval times decrease. This timed interval is set in the control module and is not programmable. The programmed intermittent cycles are as follows:








Stage 1: slow speed wiping is dependent on road speed. When the vehicle stops, the wiping will switch to a 3 second interval time.

Stage 2: fast speed wiping is controlled directly by the wiper switch.

Windshield washing: when the washing function is activated, the pump runs as long as the switch is held. The wipers switch on and will continue to for 3 wiping cycles after the switch is released.







Blocking protection: The wiper module receives a feedback signal from the wiper motor when the wipers are switched on. If this feedback signal is missing for several seconds after the wipers are switched on, the module will switch the motor off.

The wiper switch must be moved to the off position before another attempt can be made to turn the wipers on.

If this blocking protection has activated several times, the ignition must be cycled before the wipers can be switched on again.

The wiper module is not connected to the diagnostic link for troubleshooting purposes. Standard troubleshooting procedures using an ETM and multimeter must be employed to diagnose wiper/washer problems.