BMW 3 (E46). Manual - part 259
GM V sooner.
Depending on the intensity of the rain
the wipers can be operated continuously
as if set in the normal wiper stalk switch
position regardless of the knurled wheel
setting. For this reason, the vehicle
speed signal on the K-bus is not utilized
on rain sensor equipped wiper systems.
If the ignition switch is turned off with the
wiper switch in the intermittent position,
the rain sensor will only become active
after the ignition is switched back on and
one of the following occurs:
The stalk switch is moved from the
intermittent position and then back.
The knurled wheel setting is
adjusted.
The wash function is activated.
The reasoning behind this switching
strategy is to have the driver make a
conscious decision to activate the
system.
The rain sensor control module adapts
to the optics system environment as
follows:
Windshield aging: As the vehicle
ages, windshield pitting in the rain
sensor monitoring area may cause
a loss of light in the optics system.
The control module adapts for loss
of light based on the intensity of the
detected infrared light with a
cleared windshield. Therefore, rain
sensor function is not adversely
affected due to windshield aging.
Dirty windows: The rain sensor
adaptation reacts less sensitively to