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Table of Contents
SubjectPage
Central Body Electronics (ZKE III)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Objectives of the Module  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Purpose of the System  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
System Components  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Power Distribution  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Windshield Wiping/Washing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Headlight Washing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Rear Window Wiper/Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Rain Sensor  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Central Locking. . . . . .  . .  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Trunklid/Tailgate  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Remote (Keyless) Entry.  . .  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Car Memory/Key Memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Anti-Theft (DWA) System . .  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Power Windows/Sunroof . .  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Interior Lighting. . . . . . . . .  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Visual Entry Aid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Seat/Mirror/Steering Column Memory. . . . . . . . . . . . . . . . . . . . . . . . . . 58
Seat Functions  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Steering Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
General Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75
Consumer Cut Off/Overload Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Sleep Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Review Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 
     
        
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Central Body Electronics ZKE III
Central Body Electronics (ZKE III)
Purpose of the System
The Central Body Electronics (ZKE III) system manages the following functions:
GM III
• Windshield Wiping/Washing
• Windsheild Rain Sensor (AIC)
• Headlight Washing
• Tailgate Wiping/Washing
• Interior Lighting
• Central Locking
• Keyless Entry
• Key Memory
• Power Trunk Release
• Electric Opening of Tailgate
• DWA Alarm System
• Servotronics
• Consumer Cut-off/sleep mode
• DiagnosisDriver’s Door Switch Block/
Module
• Power Windows
• Mirror Adjustment/Memory/   
HeatingPassenger’s Door Module
• Mirror Adjustment/Memory/
Heating
• Power Windows
Sunroof Module
• Power SunroofSeat/Mirror/ Steering Column
Memory Module
• Seat Adjustment/Memory
• SteeringColumn Adjustment/
Memory
The ZKE III system was introduced on the E38 and is used in the E39 and E53. Most of the
functions  operate  the  same  on  these  vehicles  with  minor  changes  and  added  features  to
the system.
ZKE III  represents  the  combination  of  Body  Electronics  functions  into  one  central  control
module, the General Module (GM).  
     
        
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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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Remote (Keyless) Entry FZV
Purpose of the System
The Remote Entry System offers the following:
• Locking/unlocking of doors, luggage compartment (tailgate), fuel filler lid.
• Selective unlocking of driver’s door (same as with key in the lock cylinder).
• Arming/disarming of DWA alarm system.
• Remote unlocking of the trunk (tailgate) only.
• Comfort opening of windows and sunroof.
• Interior lighting activation (search mode).
• Panic mode alarm activation.
• Changing code signals - coded signals from transmitter change with every operation.
• Automatic correction for up to 1000 erroneous activation signals.
• Transmitter initialization procedure - including up to four key operation and Key Memory.
• Replacement batteries.
• Low transmitter battery in vehicles equipped with Check Control. 
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Central Body Electronics ZKE III
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