Control module (connected to GM V
via K-bus)
The rain sensor is on-line as soon as it
receives KL R (ignition on) operating
power.
When the windshield wiper stalk
switch is placed in the intermittent
position, the GM V signals the rain
sensor control module via the K-bus
of the request for intermittent wiping
and the position of the knurled
wheel (sensitivity).
As an acknowledgment, the rain
sensor sends a command via the
K-bus to activate the wiper motor.
If more than 12 seconds pass
before the GM V receives the
acknowledgment, it concludes the
rain sensor has a defect and
operates the intermittent wipe
function as a system not equipped
with a rain sensor. The wiper
intermittent cycling is based solely
on the knurled wheel setting.
The rain sensor continuously monitors
the windshield for rain accumulation and
signals the GM V to activate the wipers
based on the knurled wheel position and
how fast rain accumulates on the
windshield.
The knurled wheel position signal (1 - 4)
via the K-bus informs the rain sensor of
the selected level of sensitivity:
Position 1 (least sensitive) delays
the wiper activation signal.
Position 4 (most sensitive) sends
the wiper activation signal to the
Wipers and Washers
http://ebahn.bentleypublishers.com/BMW/3/E46/Repair%20Manuals/6...
7 of 11
2/25/2009 11:10 PM
