1999 BMW 750IL ignition

The key data is stored in a transponder chip. The transponder chip is a wireless read and
write EEPROM. It is powered via the ring coil at the steering lock. Power is applied elec-
tromagnetically when the key is in the ignition switch from KL R.
The power supply is used both for data transfer as well as for charging the battery. This has
been made possible by new development of the transponder chip.
As with previous systems, every press of an FZV key also provides the battery charge con-
dition. When the FZV electronics receives a low power condition message three successive
times, the GM sets a fault indicating a low battery within a specific key. The LCM is also
informed via the bus system and alerts the driver via an instrument cluster matrix message.
If the battery is recharged (used operate car), the fault will be automatically deleted when
five successive messages are received indicating a charged battery condition.
The battery has no affect on the EWS III communication function!
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Central Body Electronics ZKE III

Principle of Operation
DWA Arming/Disarming
• The DWA is armed every time the vehicle is locked from the outside with the door lock
cylinder or FZV key.
• The DWA LED flashes as an acknowledgment along with the exterior lights and a
momentary chirp from the siren.
• The GM monitors all required input signals for closed status (door closed, luggage com-
partment closed, etc.) The inputs must be in a closed status for a minimum of 3 sec-
onds for the GM to include them as an activation component. If after 3 seconds any
input signal not in the closed status is excluded (this is acknowledged by the DWA LED)
preventing false alarm activations. The hood switch can be “lifted” to the service posi-
tion to test the alarm with the hood open.
• If the DWA is armed a second time within 10 seconds, the tilt sensor and interior pro-
tection sensor are excluded as alarm activation components. This function is useful if
the vehicle is transported on a train or flat bed truck to prevent false alarm activations.
• While armed, the trunk can be opened with out the alarm being triggered as follows:
- If opened with the trunk remote button via the FZV, the GM prevents the alarm from
activating. (This feature is customizable under the Car Memory function).
- If opened with the key at the trunk lock cylinder the trunk key position switch sig-
nals the GM and in the same manner prevents the alarm from activating.
In either case, when the trunk is returned to the closed position, it is no longer con-
sidered as an activation signal.
Panic Mode Operation: When the trunk button is pressed and held, the GM is signaled
to activate the siren for the Panic Mode. The panic mode is function with either an armed
or disarmed DWA system.
Emergency Disarming: Emergency disarming occurs automatically if a key is used to turn
the ignition switch on and the EWS accepts it. The EWS signals the GM to unlock the doors
and deactivate the DWA.
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Central Body Electronics ZKE III

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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Sunroof
Purpose of the System
When the ignition key is in accessory or “on”
position press the switch or slide it to the desired
direction to lift (2), open (1) or close the sunroof.
When lifting, the headliner retracts several inch-
es. The sunroof can continue to operate after
the ignition has been switched off as long as one
of the front doors has not been opened.
Mechanically, the sunroofs are similar in design.
Some vehicles are equipped with the steel roof
while others are equipped with the glass (moon)
roof.
The anti-trap feature of the sunroof uses a hall
sensor to detect obstructions while the sunroof
is closing. The initialization procedure must be
carried out to allow the sunroof to operate in the
opening direction and allow the anti-trap feature
to function.
The anti-trap is shut down 4mm
prior to full closed and during the tilt closing
function.
System Components
Sunroof Switch:Mounted in the sunroof motor trim cover, the switch provides coded
ground signals for system operation. The following signals are generated over three wires:
• Rest position.
• Slide open request (press and hold switch - first detent of
open position).
• Automatic slide open request (press further to second
detent and release).
• Tilt open (press and hold).
• Slide close request (press and hold switch - first detent of
close direction).
• Automatic slide close request (press further to second
detent and release).
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Central Body Electronics ZKE III

Interior Lighting
Purpose of the System
The GM controls the interior lighting automatical-
ly with the status change of several monitored
inputs. The lighting can also be manually con-
trolled using the interior light switch.
In addition to the various time controls, the inte-
rior lights are also subject to the 16 minute shut
down of the GM (consumer protection).
Principle of Operation
The interior light switch is a push button switch that will carry out the opposite command
of the current status of the lights. (ie: if the interior lights are currently on, pushing the but-
ton will switch the lights off.)
• If the interior lights are switched “ON” by the button with the ignition switched ON, the
interior lights will remain on until they are switched off by the button.
• If the interior lights are switched “ON” when the ignition is switched OFF, the lights will
remain on for 16 minutes (consumer cutout).
• Pressing the interior light button for longer than three seconds will switch the lights to
continuous off. This feature is intended for workshop use.
Pressing the button again will
return the lights to the normal operational status.
• Locking the vehicle from the outside will immediately switch off the interior lights.
The ON/OFF conditions for the interior lights in the automatic mode are as follows:
ON Conditions
• Door Open.
• Switching off ignition after exterior
lights have been switched off.
• MRS Control Module crash input.
• Unlocking with FZV or pressing FZV
lock button when the vehicle is
already locked (interior search fution).
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Central Body Electronics ZKE III
OFF Conditions
• All doors closed with ignition on.
• All doors closed with ignition off after 20
seconds.
• 20 seconds after switching off ignition with
lights off.
• 8 seconds after remote control activation.
• 16 minutes with door(s) open.
• When doors are locked.

Rear Seat Interior/Reading Light Units: In
each C pillar trim panel is an interior/reading light
unit.
These units each contain an interior light that is
controlled with the front interior light and a
mechanically switched reading light on the con-
sumer cut off circuit.
Front Footwell Lights: In each front footwell,
there is also a courtesy light. These lights are
only operated when the GM provides power to
the interior lighting circuit.
On E38 and E53 the doors also contain courtesy
lights at the lower edge of the door panel (1).
Door Warning Lights (E38): The additional
“red” warning lights are installed in the edge of
the doors (2). These lights are illuminated when
the doors are opened.
Illuminated Transmission Shift Indicator
(E38): The E38 uses a microprocessor for dis-
playing the shifter position in the center console.
The processor receives shift position signals
from a console mounted range switch. The
processor illuminates the LED corresponding to
the position of the range selector.
The park position LED will remain “on” after the
ignition is switched off and stay on until the GM
goes into the “sleep” mode.
Soft Lighting Feature: The GM provides progressive voltage (up to 12v) providing the soft
on feature
to the interior lighting circuit when the interior lights are required. The GM grad-
ually reduces the full 12 volt power supply providing soft off
when interior light deactivation
is required.
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Central Body Electronics ZKE III
Park
Position
LED

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Central Body Electronics ZKE III
System Components
- with Principle of Operation
Manual Operation:The manual adjustments of the seat, mirrors and steering column are
carried out with the respective switches as with the previous systems.
The mirror adjustment switch is located in the driver’s switch block. The mirror operation
input is a digital signal that is processed by each respective module for mirror positioning.
Memory Storage: The parameters for storing memory positions are are as follows:
• With the transmission range
selector in “P” and the mirror
change over switched to the left,
switch the ignition on and press
the “M” on the memory switch.
• The memory indicator lamp swi-
tches on for 7 seconds.
• Press one of the three position
switches (1, 2 or 3) within the 7
second memory period.
• The current positions of the mir-
rors, seat and steering column
are stored for recall.
The positions of the mirrors are stored in the respective door
modules based on the position of the feedback potentiome-
ters. The positions of the seat and steering column are stored
in the seat module, based on the ripple count.
Recalling a memory position setting is possible by either
pressing and holding the recall switch (1, 2 or 3) with KL 15
“ON” or tapping the recall button (1, 2 or 3) with:
• The driver’s door open and KL 15 “OFF”.
• KL R ON and KL 15 “OFF”.
The recall movement can be interrupted at any time by touching any of the adjusting
switches.
E38/E39
E53
615200133.tiff

Passenger’s Seat (without memory)
Principle of Operation
The passenger seat control switch is purely a mechanical switching module that activates
the passenger seat motors without position monitoring capabilities. Due to the limited op-
eration requirements, the passenger seat control switch is not equipped with on board
diagnostics.
The Passenger Seat control switch is equipped with an overload protection function. If
excessive amperage is drawn due to a defective motor or a switch is stuck driving a motor
to the end limit, the function activates opening the motor control circuit.
Passenger Seat Motors: Each motor is individually controlled by the Seat Control Switch.
Each position motor is connected to the seat position switch by a two wire circuit provid-
ing motor activation in both directions (no position recognition).
Passenger Seat Adjustment: Operation of the passenger seat is always possible regard-
less of the ignition key position. Moving a position switch operates a the motor control con-
tacts directly, the switch applies voltage and ground path directly to operate the motor.
Reversing the switch simply changes the motor polarity. More than one passenger seat
motor can be run simultaneously.
Optional Seat Back Lumbar Support
The optional air bladder lumbar support system is similar in all
vehicles (if equipped). Each seat contains the following com-
ponents:
• Four position circular rocker switch in the seat base trim in
the area of the seat switches.
• Electrically controlled air compressor with over pressure cut
out under each seat.
• Two solenoid activated air controlling valve blocks (one per
air bladder). Each valve block includes an inlet and an outlet
valve. When energized they direct air into the bladder(s) to
inflate or relieve trapped air to deflate the bladders.
• Connecting hoses and air bladders in lower seat back.
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Central Body Electronics ZKE III