relay BMW 528I 1999 E39 Central Body Electronics ZKE Manual

4
Central Body Electronics ZKE III
System Components
General Module (GM): The GM is reponsible
for the operation and central coordination of
body electronics. The GM is a micro-computer
that is the central component (heart) of the
Central Body Electronics. The GM is located be-
hind the glove box.
The main objectives for using the GM are:
The GM requires inputcommands to perform
Central Body Electronics functions. The inputs
are supplied by digital switched signals such
as:
• Trunk Lock Microswitch - supplies voltage (KL
30) to the GM when switched. A path to gro-
und is provided by the GM (internally). The
GM monitors the switched input voltage.
• Central Lock Button - supplies a ground cir-
cuit to the GM when switched. The GM sup-
plies and monitors a reference voltage (5v)
that is “pulled” low when the switched gro-
und path is provided.
The GM processesthe input information and
contains “coded” instructions that allow a spe-
cific output control of functions.
The GM will produce outputfunctions using
internal transistors to switch current flow (pro-
viding voltage or ground) through circuits and
actuators. Actuators are the final controlling
devices used by the GM to operate or control
various output functions such as relays and
motors.
• Increase Overall Reliability
• Centralize Electronic Systems
• Decrease Assembly and Service Repairs
• Centralized Diagnosis of all ZKE Components
• Individualization of Features (Coding)
CENTRAL LOCK BUTTONCENTRAL LOCK BUTTON
TRUNK LOCK BUTTONTRUNK LOCK BUTTON
KL 30KL 30
TRUNK LOCK MICROSWITCHTRUNK LOCK MICROSWITCHSignal Monitor
5v
Supply/
Monitor
GM
FUEL
FILLER
FLAP
RELAY
Transistors
GM
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Central Body Electronics ZKE III
Power Distribution
The power distribution box for the
E38 is incorporated in the Electr-
onics box in the engine compart-
ment.
The power distribution box for the
E39 and E53 is inside the vehicle.
The main fuse box is located
inside the glove box above a
hinged panel.
A “pull out” fuse designation card
is also located in the fusebox. This
notes:
• Fuse value in amps
• Location
• Circuit listing by fuse
The placement of the power distribution box is
close to the main electronics carrier behind
the glove box. The modules/relays located in
the electronics carrier include (examples):
• General Module III (GM III)
• Drive away protection (EWS II)
• Anti-lock Brake (ABS/ASC+T)
• Light Check Module (LCM) - behind right kick
panel
• Overload protection relay module
An auxiliary fuse block is located in the trunk
above the battery. In addition to fuses, the
auxiliary fuse block also contains relays (exam-
ples):
• Fuel filler flap lock motor relay
• Fuel pump relay (some vehicles)
• Rear defroster relay
• Unloader relay
FUSE
DESIGNATION
CARDFUSE BOX DROPS
DOWN AFTER TURNING
TWO THUMB SCREWS
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Windshield Wiping/Washing
Purpose of the System
The windshield wiping/washing functions are controlled by the GM III when the ignition is
in position KL R or KL15. The system has four wiping stages and four interval wiping
speeds. The wiper motor output control is through two relays (double relay >98 MY, except
E38) that are located in the Electonics box (E box).
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 automati-
cally activates the wipers when the stalk switch is in the intermittent position.
System Components
Wiper Stalk Switch Input:The wiping stage inputs are coded signals through a two wire
link with a combination of high/low inputs. The wiping stages include:
Single (S): Momentarily holding the wiper
switch down in the single position provides a
momentary ground signal to activate a single
sweep in slow speed.
Slow (I) and Fast (II): The stage I and stage II
wiping speeds are road speed dependent.
Stage I switches to intermittent when the vehi-
cle is stopped and stage II switches to stage I
when stopped.
Windshield Washing: The wash request provides a switched ground input to the GM by
pulling the stalk rearward. The GM activates the windshield washer pump directly.
Intermittent (Int): The intermittent wiping time inputs are provided by a potentiometer
mounted in the wiper stalk switch (1 through 4). The intermittent wiping intervals are also
dependent on the road speed. As road speed increases, the wiping interval is shortened.
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Central Body Electronics ZKE III
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Central Body Electronics ZKE III
Blocking Protection = Return
Contact Signal must be
present every 16 seconds
or motor will be deactivated >98 MY
1.49v-3.5v
Headlight Washing (if equipped):When the headlights are on, the headlight washer
pump is activated with the first activation of the windshield washer pump. It is only activat-
ed again after five succesive windshield washer cycles during the same ignition key on cycle
(rest function). The GM recognises headlights on via K-Bus signalling. The GM provides a
ground on the headlight washer relay control circuit providing pump operation. The head-
light washer pump is located on the side of the washer fluid reservoir.
System Components: Inputs - Processing - Outputs
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E53 Shown

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 Body Electronics ZKE III
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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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Central Body Electronics ZKE III
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Central Body Electronics ZKE III
System Components: Inputs - Processing - Outputs
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E38 is
Direct
w/o Relay

Door Contact Hall Sensor: Also included in the drivers door actuator is a third hall effect
sensor. This sensor signals the door open/closed status to the GM. This sensor replaces
the door jamb mechanical switch of previous systems. The rotary latch plate position acti-
vates the door contact hall sensor.
• When the door latch is closed, current flow
through the sensor is <5 mA (0).
• When the door is open, current flow through
the sensor is >12 mA (1).
The passenger side front door and both rear
door lock actuators only include this hall effect
sensor (hall sensor 3). Hall sensors 1 & 2 are
not required.
Trunk Lid Close (E38 SCA)/Tailgate and Window Latching System (E39/E53): The
tailgate/trunk lid is opened by any of the three input signals: FZV, remote button and unlock
switch pad (push - trunk lock cylinder E38).
These inputs request the rear latch
actuator control circuit to be
switched to ground (exception:
presence of road speed signal,
key on with FZV request.)
The rear latch actuator unlatches
the mechanism and signals the
GM of the open latch status. The
SCA motor rotates the striker
180
O. Feed-back signalling stops
the motor. E38 - When closing the
trunk lid the trunk latch micro-
switch signals the GM to activate
the SCA motor to pull the lid
down.
Rear window unlatching is requested by the rear window switch ground signal. This signal
initiates activation of the rear window actuator relay control circuit which activates the rear
window actuator. The actuator unlatches the mechanism opening the window. The latch
simultaneously provides an open window signal for the rear window wiper motor module
as well as an interior light on request (via the wiper module).
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Central Body Electronics ZKE III
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E39 Sport Wagon
Shown
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All window operations signals are digital inputs to the door module and GM III.
• Comfort closing/opening of the windows from the driver’s lock cylinder. The remote key
provides opening only.
• When the ignition key is in accessory or “on” position press the switch to open or close
the windows. Window operation is possible with the ignition switched off until a front
door is opened or 16 minutes (maximum) has elapsed.
• Window load switching is through relays. The front window control relays are located in
the door modules, the rear window relays are in the GM III. The GM III monitors the cur-
rent draw for end limit position. The maximum run time for the window motors is limit-
ed to 6 seconds in the one-touch mode. This allows the motors to be switched off if the
end limit load sensing fails.
E53 Style Window Switches:The E53 power window switch design is a push - pull type
switch. Each switch provides the GM with the coded ground signaling strategy as previous
two wire switches.
Pushing a switch to the first detent and holding
provides
a single ground signal on one wire
requesting the GM to operate the window
motor in the down direction.
When released, the ground signal is removed
and the window motor stops.
Momentarily pushing the switch to the second
detent and releasing provides
an additional
ground signal on the second wire requesting
the “one touch mode”, operating the window
motor automatically.
The motor runs the window down until it reach-
es the end stop.
The switch functions in the same manner for
the upward run of the window motor but the
ground signal sequencing is reversed.
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Central Body Electronics ZKE III
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Power Window Motors: The window motors are mounted on the cable regulators. The
window motor control circuit consists of two wires for operating the motor in both direc-
tions.
The motors are activated by relays in the GM of door
modules (front doors). The relays provide either power
or ground depending on the direction of window travel.
The GM controls the polarity of the motor based on a
request to run the window (window switch,
Convenience Opening/ Closing).
The windows are run to the limit stops which is detect-
ed by an amperage increase in the control circuit.
Additionally, the window run cycle is limited to a 6-8
second duration if in case the amperage increase is not
detected or there is a malfunction with the regulator.
Window Motor Limit Stop Function: If the windows are run up and down continuously
a limit stop function is activated to prevent the window motors from overheating. The GM
monitors the number of times the window motors are activated. Each cycle is counted and
stored in memory.
If the repetitive window activation (up/down) exceeds one minute, the GM deactivates the
internal relays and disregards any further input requests. The GM provides motor activation
after a short duration but not for the full one minute monitoring cycle. Over time, the GM
slowly reverses the stored count of activation until the stored number equals 0.
Convenience Opening/Closing: The GM provides the convenience open/close feature
providing control of the power windows (and sunroof) from outside the vehicle with the key
in the driver’s door lock cylinder. The FZV provides the same function for the opening only.
• The anti-trap feature is active during convenience closing from the driver’s door lock.
• The convenience open feature provides outside activation of the windows and sunroof
in the same manner.
• If the GM receives a request to operate convenience close or open for more than 110
seconds, the function is deactivated and a fault code is stored.
• The Car Memory Feature can activate and deactivate the Convenience Open Feature
from the FZV’s control.
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Central Body Electronics ZKE III
FRONT DOOR
REGULATOR
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