wipers BMW X5 2001 E53 Central Body Electronics Workshop Manual

WINDSHIELD WIPING/WASHING
• The GM III controls all of the windshield wiping/washer and headlight washing functions.
• Output control of the wiper motor is
through the windshield wiper double
contact relay. The relay is located in the
engine compartment E-box and is tan in
color.
• The system continues to have four wiping
stages and four interval wiping speeds.
The wiping stage inputs are coded signals
through a two wire link with a combination
of high/low inputs as on previous
systems.
• The Windshield Wiping System can also be supplemented with the Rain Sensor system
as optional equipment. The Rain Sensor detects rain drops on the windshield and
automatically activates the wipers when the stalk switch is in the intermittent position.
Wiper Stalk Switch:
SINGLE: Holding the wiper switch down in the single position provides a ground signal to
activate the slow speed circuit providing wiper operation until the switch is released.
INTERMITTENT: The intermittent wiping time inputs are provided by a potentiometer
mounted in the wiper stalk switch.
• The intermittent
wiping intervals are
dependent on the
road speed.
• As road speed
increases, the
wiping interval
delay is decreased.
SLOW (I) AND FAST (II): The stage I and stage II wiping speeds are also affected by road
speed. The factory encoded settings are the same as previous systems:
• Stage I automatically switches to intermittent when the vehicle is stopped
• Stage II switches to stage I when stopped.
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WINDSHIELD WIPER
DOUBLE RELAY

REAR WINDOW WIPER/WASHER SYSTEM
The tailgate window wiper/washer system is included in the scope of ZKE however is not
controlled directly by the GM. The control electronics are integrated into the rear wiper
motor assembly. It contains two hall sensors, one for monitoring park position and other
for the end stop, or to signal reverse direction of the wiper motor.
The rear wiper system is operator controlled
through the wiper stalk switch providing the
following functions:
• Intermittent rear window wiping
• Programmed rear window wiping interval
• Operation of the rear window washer
Pressing the wiper stalk forward to the first
detent activates the rear wiper in the
intermittent mode.
The default timed interval is approximately 12 seconds. The full sweep and park positions
are recognized by the two hall sensors on the motor gear assembly. If the wiper is switched
OFF, the wiper blade will return to the park position.
The programmed wiper interval procedure is identical to the E39 sport wagon; Briefly
switch the rear wiper ON/OFF, Wait the desired interval time, Switch the rear wiper ON
again. The OFF time will be the programmed interval - up to approx. 30 seconds
Rear window washing is activated by pressing the wiper stalk switch to the full forward
position. The washer pump operates followed by two full wiping cycles. The wipers will then
switch to the intermittent wiping mode.
When the transmission is shifted into reverse, the wiper will switch to continuous operation
until the vehicle is shifted out of reverse. This high signal is provided by the LCM III when it
activates the back up lights.
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OPTIONAL RAIN SENSOR (AIC)
The Windshield Wiping System will also be available with an optionally equipped Rain
Sensor. The Rain Sensor provides added driver convenience and enhances safety by
automatically activating the intermittent function of the windshield wipers when water
droplets are detected on the windshield.
COMPONENTS:
The rain sensor unit is mounted on the top center area of the interior windshield surface
directly behind the rear view mirror. The unit contains:
•Optical Prism Body:This portion of the unit is
permanently fixed to the windshield. It can not be
removed and can only be replaced with a
replacement windshield.
The prism body has a reflective surface that faces
the back of the windshield. The prism body also
acts as the windshield mount for the Rain Sensor
Control Module.
•Rain Sensor Control Module:The control module incorporates the following;
- Infra Red Emitter and Detector Diodes
- Optics heater (prevents condensation from forming on diodes and prism)
- Optics evaluation and control electronics
- Photo cell to detect night time driving
The control module requires four signals for operation; KL R, KL 31, Windshield Wiper
Motor Park Signal Feedback and K Bus interface.
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GM III

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RAIN SENSOR FUNCTION:
The rain sensor is online as soon as it receives KL R operating power.
• When the windshield wiper stalk switch is placed in the intermittent position the GM
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 acknowledgement, the rain sensor sends a command via the K Bus to activate
the wiper motor. If more than 12 seconds pass before the GM receives the
acknowledgement, the GM 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 to activate the wipers based on the knurled wheel position and how fast the 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 GM sooner.
• When the wiper motor park contacts signal the GM of the wiper arm position, the signal
is simultaneously sent to the rain sensor as an indication that the windshield has been
cleared of water drops and causes the rain sensor to reset the sensitivity delay timer
back to 0.
• If night time driving is detected via the integral photocell, the sensitivity to water droplets
is increased causing a shorter delay than day time driving.
• Depending on the intensity of the rain the wipers will 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.
- or the wash function is activated.
The reasoning behind this switching strategy is to have the driver make a conscious
decision to activate the system themselves.