BMW 528I 1999 E39 Central Body Electronics ZKE Manual

Rear Window Wiper/Washer System (E39 Sport Wagon and E53): The system is
included in the scope of ZKE however is not controlled directly by the GM. The control elec-
tronics are integrated into the rear wiper motor assembly. The control electronics 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 control electronics are connected to the vehicle
electrical system via a single seven pin connector.
The rear wiper system is operator controlled
through the wiper stalk switch providing the fol-
lowing 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 intermit-
tent mode
. The timed interval is approximately 7-12 seconds. The full sweep and park posi-
tions 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 as follows:
• 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. Additionally, the system automatically controls the
following safety and convenience features:
• Wiper interrupt with the rear glass opened
• Wiping interrupt with a blocked wiper arm
• Continuous wiping when the vehicle is shifted into reverse
When the transmission is shifted into reverse, the wiper will switch to continuous operation
until the vehicle is shifted out of reverse. This signal (high) is provided by the LCM III when
it activates the back up lights.
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Central Body Electronics ZKE III
Rain Sensor (AIC - if equipped)
Purpose of the System
The Windshield Wiping System is also available with an optionally equipped Rain Sensor.
The Rain Sensor provides added driver convenience and enhances safety by automatical-
ly activating the intermittent function of the windshield wipers when water droplets are
detected on the windshield.
System Components
Rain Sensor: The 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 per-
manently 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 driving
The control module requires four signals for operation; KLR, KL31, Windshield Wiper Motor
Park Signal Feedback and K-Bus interface.
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GM III
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Central Body Electronics ZKE III
Principle of Operation
The optical infra red portion of the sensor operates by the principle of refraction (bending
of a light ray). The rain sensor control module activates the emitter diode which sends a
beam of infra red light through the windshield on an angle. The set angle is important
because it provides the beam with a calculated reflective path back to the detector diode.
The beam is reflected back into the windshield due to the density difference of the glass
compared with the ambient air on the outside surface of the glass. When the windshield is
clean (no rain drops, moisture or dirt) the detector diode receives 100% of the infra red light
that the was sent by the emitter. With this condition, the rain sensor evaluation electronics
determines the windshield is free of rain drops.
The density of water is closer to that of glass than air. When rain starts to accumulate in
the sensor monitoring area, it causes part of the infra red beam to extend past the outside
surface of the glass and into the rain drop. When this occurs, the beam is refracted and
only part of the beam returns to the detector diode.
The rain sensor evaluation elec-
tronics determines the windshield
has a few rain drops (or dirt) on it.
The intensity of the returned infra red beam diminishes proportionally with an increase of
water droplets. The rain sensor control module generates a signal proportionate to the
amount of rain on the windshield and broadcasts it to the GM via the K bus.
The GM activates the intermittent wipe cycle if the windshield wiper stalk switch is in the
intermittent position. It also adjusts the frequency of wiping the windshield depending on
the four position thumb wheel.
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Central Body Electronics ZKE III
Rain Sensor Function
The rain sensor is online as soon as it receives KLR operating power.
• When the windshield wiper stalk switch is placed in the intermittent position the GM sig-
nals 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 acknowledge-
ment, 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 select-
ed 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 causeing 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 fol-
lowing 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 deci-
sion to activate the system themselves.
Rain Sensor Control Module Adaptation
The rain sensor control module adapts to the optics system environment as follows:
Windshield Aging:As the vehicle ages the possibility of stone chipping in the rain sensors
monitoring area may occur which will cause a loss of light in the optics system.
The control module adapts for loss of light based on the intensity of the detected infra red
light with a cleared windshield (wiper motor park signal). Therefore, the rain sensors func-
tion is not adversely affected due to windshield aging.
Dirty Windows:The rain sensor adaptation reacts less sensitively to a dirty windshield
(dirt, road salt, wax residue) after a completed wipe cycle. A dirty windshield has a film on
it that diminishes the ability of the infra red to refract into present water droplets. This caus-
es a delay in the rain sensor detection capabilities which lengthens the time intervals on an
intermittent wipe.
Windshield Wiper System Failsafe Operation
The GM provides failsafe operation of the wiper system if faults are detected with any of the
following input signals:
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Central Body Electronics ZKE III
Function Faulted Input Detected Failsafe Function
Intermittent Wipe
Short or open circuit of
the knurled wheel signalDelay value for
setting 3 used.
Intermittent wipe
with Rain SensorFaulted Rain Sensor or
K-Bus Signal corruptNormal Intermittent
wipe implemented
Wiper Motor not
Functional MovingPark contact feedback
signal takes longer than
16 secondsWiper motor control
deactivated for 3
minutes

Workshop Hints
Windshield Wiper Blade Service
To access the wiper blades for cleaning or replacement,the following is required:
• With the ignition switched on (KL15), switch the wiper stalk to the “Intermittant” wipe
mode.
• Switch the ignition off when the wiper arms are in the “upright” position.
CAUTION: Do not allow the wiper arm to spring back against the windshield, glass
breakage will occur!
Rain Sensor Equipped Vehicles
Make sure the wiper blades are in perfect condition. Only use window cleaner to clean the
windows. Dirty windows can cause the Rain Sensor control module to set a fault
due to the end limits of its adaptation abilities.
Rear Window/Wiper
The wiper arm and driveshaft are connected by
splines.
Special tool #61 1 320 is required to hold the drive
shaft in the park position prior to installing the wiper
arm on to the drive shaft.
Windshield Wiper System Diagnosis
The GM monitors the following circuits:
• Wiper Potentiometer • Wiper Motor • Terminal 30
• Double Relay • Windshield Washer Pump
Note: The wiper/washer operation will be interrupted during engine cranking. The GM pro-
vides this “unload” feature to preserve the battery voltage for the starter motor.
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Central Locking
Purpose of the System
The Central Locking System provides locking/
unlocking of the entire vehicle from one central
exterior point. From the driver’s door or the
remote (key-less) entry, a lock/unlock request will
lock/unlock all exterior doors, luggage compart-
ment and the fuel filler flap.
From inside, the vehicle can be locked/ unlocked using a cen-
tral locking button located in the center console. Individual
doors can be unlocked manually by pulling twice on the inte-
rior door handle.
From 2000 MY
- if the vehicle has been double locked, press
the central locking button and pull the interior door handle
twice (alarm will sound when the door opens).
Locking the vehicle from the central switch will “single lock” all
doors, luggage compartment and not lock the fuel filler flap.
The Central Locking System utilizes the GM III and Door Modules to carry out all of the lock-
ing/unlocking features:
• Remote (key-less) entry is standard.
• When locked from the outside, the vehicle will double lock and arm the DWA System. The
ignition must be switched off and the driver’s door must be opened and closed.
• Selective unlocking from the outside of the vehicle. Unlocking from the driver’s door or
remote transmitter will only unlock the driver’s door and disarm the DWA System. A sec-
ond request will unlock the remaining doors and luggage compartment. This feature can
be modified for individual users in Key Memory to open all doors from a single request.
• A single central locking button is installed in the center console that will operate when all
of the doors are closed. Locking the vehicle from the central switch will “single lock” all
doors, luggage compartment and not lock the fuel filler flap. When unlocking, a single
request will unlock the driver’s door only. This feature can be modified for individual users
in Key Memory to open all doors and luggage compartment from a single request.
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• A remote luggage compartment button is installed in the left kick panel (center console
in the E53) to open the luggage compartment from inside the vehicle.
• The EWS is interfaced for double lock monitoring and unlock function. With the presence
of an accepted EWS key in the ignition, the vehicle will be unlocked and disarm DWA.
• The automatic locking feature (> 99 MY) activates the door locks when a road speed
signal of 5 MPH and engine RPM is detected via the K-Bus. The factory default setting
of this feature is off (can be encoded on for individual users with Key Memory function).
• In the event of an accident (ignition on), the GM will be signalled to unlock all doors.
Hardware Features:
• The external lock cylinders are located in the
driver’s door and luggage compartment lid
(E53/E39 Sport Wagon does not have a tail-
gate lock cylinder).
• The driver’s door and luggage compartment
incorporates an overrunning lock cylinder. The
lock cylinder will free wheel or spin If any key
other than the vehicle key or tool, such as a
screw driver, is inserted into the cylinder. The
lock cylinders can be manually locked/un-
locked by turning the key “past” lock/unlock.
• The door lock buttons are mechanically uncoupled from the
lock actuators when locked.
The door lock buttons “mechanically” lock the individual
doors. This provides manual locking in the event of a central
locking malfunction.
• Child safety locks (located in
the rear doors) are actuated
by inserting a key in the slot on
the door latch or by sliding a
lever (dependent on model).
The door can now only be
opened from outside.
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Door
Button
Lock
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• The luggage compartment can be manually
locked with a “Master Key” and leaving the
lock cylinder in the horizontal position which
prevents opening by any other method (sec-
ured for valet).
The luggage compartment release button in-
side the vehicle will also be ignored by the GM.
Prior to 2000 MY the vehicle could be locked/
unlocked using the luggage compartment lock
cylinder.
• The glove box has a lock cylinder to secure the
contents by manual locking with a “Master
Key” and leaving the lock cylinder in the hori-
zontal position which prevents opening by any
other method (secured for valet).
• The E38 has a lever behind the glove box han
dle which permits locking the glove box with-
out a key. Opening still requires a key.
The valet key is not mechanically capable of
entering either of these lock cylinders.
• The Fuel Filler Flap mechanical release is found
in the right side of the luggage compartment.
The “pull tether” is behind the button as shown
on the right.
Note: Continuous operation of locking/unlocking will cause a timed arrest of the
locking system. When activated, the timed arrest lasts for 2 minutes (or recycle
the ignition KL15). The “crash” signal will override the timed arrest and unlock the
vehicle.
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System Components
- with the Principle of Operation
Driver’s Door Lock: The lock/unlock signals
from the driver’s door lock cylinder are input to
the driver’s door module from the two micro
switches on the lock cylinder. The driver’s door
switchblock module carries out the locking func-
tion of the driver’s door.
The windows and sunroof can be closed or
opened by holding the key in the lock/unlock
position (convenience closing/opening feature).
The signal to lock the remaining doors and fuel filler flap is passed over the P-Bus to the
GM III and passenger’s door module. The locking of the passenger’s door is carried out by
the passengers door module. The rear doors, luggage comparment and fuel flap locking
are carried out directly by the GM III. All four doors will be pulled into the double lock posi-
tion when locking from the driver’s door.
The control of the actuators in the front doors is through final stages in the door modules.
The rear doors, trunk and fuel filler flap actuators are controlled by internal relays in the GM
III. When locked, the GM III will not carry out any opening commands from the central lock-
ing button or luggage comparment interior release button.
Luggage Compartment Lock Cylinder (except E53/E39 Sport Wagon): The vehicle
can be locked/ unlocked (prior to 2000 MY) from the luggage compartment lock cylinder.
The lock/unlock micro switch inputs are processed in the GM III and the locking commands
are carried out.
The signal is passed over the P-Bus to the
door modules to lock/unlock the front
doors and the GM III locks the rear doors
and fuel filler flap.
All door actuators are placed in the double
lock position. Removing the key in the hor-
izontal position will activate the valet mode
and prevent the valet key from opening the
luggage comparment.
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