BMW 528I 1999 E39 Central Body Electronics ZKE Manual
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LED Status (Keys equipped with LED):
The following functions can be checked with the LED:
• Flashing  LED  when  pressing  a  button.
Indicates  that  the  data  is  being  transmitted.
(battery voltage between  3.2 - 2.6 volts)
• No LED activity when pressing a button:
1. ZKE  responds  to  pressed  button  only  to
unlock  a  locked  vehicle.  Indicates  the  bat-
tery is between 2.6 - 2.2 volts.  Replace bat-
tery.
2. No  unlock  of  vehicle.  Indicates  battery  is
below 2.2 volts. Replace battery.
FZV Key Test: Pressing the trunk release and lock buttons together activates the key test. If
the battery and FZV key EEPROM are  “OK”, the LED will come ON for approximately 1 sec-
ond.
FZV Key Rechargeable Battery
From KL R, the battery inside the key head is charged inductively by the EWS ring antenna
via a coil antenna integrated in the key. The charging process is controlled by electronic
circuitry integrated in the key.
• The service life of a radio-control key used under normal conditions corresponds to the veh- 
icle lifespan.
• If the FZV keys are not used (ie: stored in a drawer), the battery will be discharged after
approx. 1.5 years.
• The time required to fully charge a discharged battery is approx. 30 hours.
• The remote control can be operated about 15 times after a charging period of approx. 30  
minutes (driving time).
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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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Anti-Theft (DWA) System
Purpose of the System
The  DWA  alarm  system  offers  vehicle  protection  by  monitoring  the  doors,  hood,  interior,
luggage  compartment  and  vehicle  tilting.  When  activated,  DWA  deters  theft  by  sounding
an  alarm  siren  for  30  seconds,  flashing  the  low  beam  headlights  (high  beam  on  Xenon
equipped models) and four way flashers for 5 minutes. 
The control electronics for DWA are integrated in the general module. The DWA - LED 
indicator is located in the rear view mirror (E38 in the top center IHKA grille).
The system is “armed/disarmed” from the driver’s door lock cylinder, remote transmitter or
luggage compartment lock cylinder. The alarm is immediately deactivated when disarmed
with the key in the driver’s door lock cylinder (may be deactivated in Conversion) or remote
transmitter.  
The GM utilizes existing components and/or circuits as part of the DWA system:
•  Door latch switch/sensor contacts (door open/closed).
•  Trunk lid switch contact (monitored for closed trunk).
•  Trunk  lock  key  position  switch  (located  on  the  trunk  lock,  this  switch  signal  prevents
DWA from activating if armed when the trunk is opened with the key).
•  Hood switch (monitored for closed hood, located under the hood).
•  DWA status LED (part of rear view mirror).
The additional components required are:
• Interior Sensor                    • DWA Siren                      • Tilt sensor
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System Components
Interior  Sensor  FIS  (up  to  99  MY): The  interior  sensor  is  mounted  in  the  center  of  the
headliner panel. Due to the design of the vehicles interior, the sensor is uni-directional and
must be installed in the proper direction to ensure proper operation of the system.
When the alarm system is armed, the sensor emits electromagnetic waves at a frequency
of  2.45  GHz.  As  long  as  nothing  is  moving  in  the  vehicle,  the  waves  as  bounced  back  to
the sensor at the same frequency. The sensor monitors these bounced back waves as an
indication that nothing is disturbed within the vehicle.
If  a  foreign  object  enters  the  vehicle,  the  frequency  of  the  bounced  back  signal  changes.
The sensor monitors the changed frequency and triggers the alarm.
Every  time  the  DWA  system  is  armed,  the
sensor  adapts  to  what  ever  objects  might  be
stationary in the interior. 
This  allows  packages  or  objects  to  be  left
inside  the  car  without  effecting  the  operation
of  the  system.  The  sensitivity  of  the  sensor  is
set so that the moving object must be at least
as  large  as  a  bumble  bee.  This  prevents  a
false  alarm  from  occurring  from  small  insects
that might be caught in the vehicle.
The FIS is switched OFF when the vehicle is locked two times within ten seconds. The LED
will flash one time for confirmation. This allows the sensor to be switched OFF to avoid false
alarms when the windows are left open for venting.
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Interior Sensor UIS (after 99 MY):Similar to the FIS, the UIS monitors the vehicle interi-
or for motion. The UIS uses ultrasonic sound wavs instead of microwaves (less suceptable
to magnetic interference). The UIS is a combined transmitter and receiver.
The interior sensor is mounted in the center of the headliner panel. Due to the design of the
vehicles  interior,  the  sensor  is  uni-directional  and  must  be  installed  in  the  proper  direction
to ensure proper operation of the system (trim cover ensures directional installation).
Every  time  the  DWA  system  is  armed  (signal  STDWA),  the  sensor  adapts  to  what  ever
objects  might  be  stationary  in  the  interior.  The  sensor  emits  ultra  sonic  waves  in  a  pro-
grammed timed cycle. It receives echos of the emitted waves.  
The UIS amplifies the received sound wave signals and compares them with the transmit-
ted  waves.  The  UIS  also  checks  the  incoming  echos  for  background  hiss  (wind  noise
through a partially open window) and adapts for this.
• If the echos are consistently similar, no movement is detected.
• If  the  echos  are  altered,  (inconsistent),  the  UIS  determines  motion  in  the  interior  com-
partment. 
If motion is detected, the UIS changes to a constant cycle and the echo is compared again.
If the inconsistency is still present the UIS sends the activate siren signal (INRS) to the GM.
The UIS is switched OFF when the vehicle is locked two times within ten seconds. The LED
will flash one time for confirmation. This allows the sensor to be switched OFF to avoid false
alarms when the windows are left open for venting.
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Tilt Sensor (Liquid Type - E38/E39 to 97 MY): The Tilt Sensor consists of a conductive
liquid chamber, a processor board and metal probes (located in the luggage compartment).
The probes are submersed in the liquid and produce a resistance value dependent on the
tilt of the sensor (angle of vehicle). This resistance value becomes the static point when the
DWA System is armed.
If the vehicle is jacked-up or lifted,
the  angle  of  the  liquid  changes
producing  a  change  in  the  resis-
tance  value.  The  sensor  recog-
nizes  this  change  and  signals  the
GM to activate the DWA alarm.
The  resets  at  the  new  angle.  This
allows  the  DWA  to  remain  armed
and  re-activate  the  alarm  if  the
vehicle is moved again.
As with the interior sensor, the tilt sensor is also switched OFF when the vehicle is locked
two times within ten seconds. The LED will flash one time for confirmation. This allows the
sensor to be switched OFF for transportation purposes.
Tilt  Sensor  (Electronic  Type  from  98  MY): Located  in  the  luggage  comparment  area,
the tilt sensor is an electronic sensing device with the sole purpose of monitoring the vehi-
cle's parked angle when DWA is armed.
The  sensor  requires  three  signal  wires  to  func-
tion:
•  KL 30 - Constant battery voltage
•  Signal "STDWA"; switched ground input sig-
nal  provided  by  the  GM  indicating  DWA
armed/disarmed status. 
The tilt sensor is used as a splice location for  
the STDWA signal to the Siren and UIS int-  
erior protection sensor. 
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•  Signal "NG"; switched ground output signal provided to the GM. The signal is used for
two purposes,
1. As  a  momentary  acknowledgment  that  the  tilt  sensor  received  STDWA  and  is  cur-
rently monitoring the vehicle angle.
2. If the tilt sensor detects a change in the vehicle's angle when DWA is armed, signal
NG is switched to inform the GM to activate the siren. 
When  the  tilt  sensor  receives  the  STDWA  signal  from  the  GM  it  memorizes  the  vehicle's
parked  angle.  The  angle  of  the  vehicle  is  monitored  by  the  solid  state  electronics.  Once
armed,  if  the  angle  changes,  the  tilt  sensor  provides  a  switched  ground  signal  to  the  GM
to activate DWA.  
As with the interior sensor, the tilt sensor is also switched OFF when the vehicle is locked
two times within ten seconds. The LED will flash one time for confirmation. This allows the
sensor to be switched OFF for transportation purposes.
Glass Breakage Sensors (Early E38 - before FIS Sensor): The door windows (includ-
ing  the  rear  quarter  glass  wire  loop)  are  monitored  by  inductive  sensors  mounted  on  the
inside of the door behind the trim panel. A closed window is recognized by a magnetic plate
on the glass lining up with the sensor. 
If the glass is broken, the plate falls away and the signal from the sensor changes and the
GM will activate the alarm.
Alarm  Siren: The  alarm  siren  is  mounted  in  the  rear  wheel  well,  behind  the  inner  wheel
housing cover (early E38 used an alarm horn). The E53 alarm siren is located in the left side
of the engine compartment.
The  siren  contains  electronic  circuitry  for  producing  the  warn-
ing tone when the alarm is triggered. The siren also contains a
rechargeable battery that is used to power the siren when the
alarm is triggered.  
The rechargeable battery will allow the siren to sound if it or the
vehicle’s  battery  is  disconnected.  The  siren  battery  is
recharged, from the vehicle’s battery, when the alarm is not in
the armed state.
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The  siren  has  four  wires  connecting  it  to  the  system;  KL  30,  KL  31,  activate  siren  signal
(SIRENE) and the arm/disarm signal (STDWA).
The  arm/disarm  output  signal  from  the  GM  is  provided  to  the  Tilt  sensor,  FIS/UIS  sensor
and the siren. The arm/disarm signal is a switched ground that signals the components of
an armed/disarmed status.
The activate siren signal to the siren is high whether DWA is armed or disarmed. If a mon-
itored input activates the alarm, the high signal to the siren is switched to a 50% duty cycle
at the GM. The control circuitry in the siren activates the siren driver. 
If the DWA is armed and the battery is disconnected the siren recognizes the normally high
“SIRENE” signal as suddenly going low, the siren is activated.
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Central Body Electronics ZKE III
SIRENE
STDWA
97 MY E38 Shown 
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System Components:   Inputs - Processing - Outputs
97 MY E39 Shown 
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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