
TABLE OF CONTENTS
Subject Page
Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Power Distribution  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Windshield Wiping/Washing  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Optional Rain Sensor (AIC)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Central Locking  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Remote RF Keyless Entry  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Model Year 2000 FZV Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Car Memory / Key Memory  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Power Windows  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Window Anti-Trap Detection  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Sunroof  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Interior Lighting  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Anti-Theft (DWA) System  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Tilt Sensor  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Interior Protection (UIS)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Alarm Siren  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Alarm Indication  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
Seat Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Mirror Operation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Seat Operation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Steering Column Operation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
General Functions of ZKE III  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
Diagnosis/Troubleshooting  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
Revised 6-96 

INTRODUCTION
The  Central  Body  Electronics  (ZKE  III)  equipped  on  the  X5  includes  the  following  sub-
systems under the total scope of its control:
• Windshield/tailgate wiping/washing,
including windshield rain sensor (AIC).
• Interior lighting
• Central locking
• Keyless entry
•  Tailgate release
The following is an overview of new or changed features found on the X5 ZKE III variant. 
• Passenger’s  door  module  is  now  incorporated  into  the  passenger’s  door  switchblock
module.
• Sunroof module (SHD)  located on the K bus.
• The Central Locking system uses a new style door lock actuator with hall effect sensors
similar to E46.
• The  GM  III  is  responsible  for  the  Key  Memory  feature.    It  provides  the  added
convenience  of  identifying  users  of  the  vehicle.   Whenever  the  vehicle  is  locked  or
unlocked  via  the  FZV  keyless  entry  system,  a  unique  key  identification  signal  (key
number) is transmitted to the General Module.
The  key  identification  signal  alerts  the  GM  to  communicate  with  other  control  systems
over the K Bus to store (when locked) or reset (when unlocked) certain driver adjustable
settings  for  the  driver  using  the  specific  key.    The  GM  also  resets  certain  driver
adjustable settings that it controls directly.
• Power windows/Sunroof
• DWA alarm system 
• Mirror - adjustment/memory/heating
• Seat adjustment/memory
• Steering column adjustment/memory
• Consumer cut-off/sleep mode
ZKE - 2 

WINDSHIELD WIPING/WASHING
• The GM III controls all of the windshield wiping/washer and headlight washing functions.
• Output  control  of  the  wiper  motor  is
through  the    windshield  wiper  double
contact  relay.    The  relay  is  located  in  the
engine  compartment  E-box  and  is  tan  in
color.
• The system continues to have four wiping
stages  and  four  interval  wiping  speeds.
The wiping stage inputs are coded signals
through a two wire link with a combination
of  high/low  inputs  as  on  previous
systems. 
• 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
automatically activates the wipers when the stalk switch is in the intermittent position.
Wiper Stalk Switch:
SINGLE: Holding the wiper switch down in the single position provides a ground signal to
activate the slow speed circuit providing wiper operation until the switch is released.
INTERMITTENT: The  intermittent  wiping  time  inputs  are  provided  by  a  potentiometer
mounted in the wiper stalk switch. 
• The intermittent
wiping intervals are
dependent on the
road speed.  
• As road speed
increases, the
wiping interval
delay is decreased. 
SLOW (I) AND FAST (II): The stage I and stage II wiping speeds are also affected by road
speed.  The factory encoded settings are the same as previous systems:
• Stage I automatically switches to intermittent when the vehicle is stopped 
• Stage II switches to stage I when stopped.
ZKE - 6
WINDSHIELD WIPER
DOUBLE RELAY  

ZKE - 8
WINDSHIELD WASHING:
Pulling  the  Windshield  Wiper  Switch  rearward  closes  the  “wash”  contact  providing  a
switched ground input to the GM.  The GM activates the windshield washer pump directly
via a power output final stage transistor.
HEADLIGHT WASHING:
When  the  headlights  are  on,  the  headlight
washer  pump  is  activated  with  the  first
activation  of  the  windshield  washer  pump.
The  GM  recognizes  headlights  on  via  K  bus
signalling.
Within  the  same  “on”  cycle  (ignition  key  has
not  been  switched  off),  it  is  only  activated
again after five successive windshield washer
cycles.
The  GM  provides  a  ground  on  the  headlight
washer  relay  control  circuit  providing  pump
operation.  The relay is located in the e-box.
The  X5  uses  three  separate  washer  pumps
which are all easily accessible on the 5.3 liter
washer  fluid  reservoir  located  in  the  engine
compartment.  
GM III
HEADLIGHT WASHER
RELAY
HEADLIGHT
WASHER
PUMP
WINDSHIELD
WASHER
PUMP
TAILGATE
WASHER
PUMP   

REAR WINDOW WIPER/WASHER SYSTEM
The  tailgate  window  wiper/washer  system  is  included  in  the  scope  of  ZKE  however  is  not
controlled  directly  by  the  GM.      The  control  electronics  are  integrated  into  the  rear  wiper
motor  assembly.    It  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  rear  wiper  system  is  operator  controlled
through  the  wiper  stalk  switch  providing  the
following 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
intermittent mode. 
The default timed interval is approximately 12 seconds. The full sweep and park positions
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  identical  to  the  E39  sport  wagon;  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.
When the transmission is shifted into reverse, the wiper will switch to continuous operation
until the vehicle is shifted out of reverse. This high signal is provided by the LCM III when it
activates the back up lights.
ZKE - 9  

THEORY 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
electronics  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 III via the K bus.
The GM III 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.
ZKE - 11 

ZKE-13
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
function 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  causes  a
delay  in  the  rain  sensor  detection  capabilities  which  lengthens  the  time  intervals  on  an
intermittent wipe.
SERVICE NOTE FOR VEHICLES EQUIPPED WITH THE RAIN SENSOR: 
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.   
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:
WINDSHIELD WIPER SYSTEM DIAGNOSIS
The  GM  monitors  the  circuits  of  the  wiper  potentiometer,  wiper  motor,  double  relay,  the
windshield washer pump and terminal 30.  
FUNCTION FAULTED INPUT DETECTED FAILSAFE FUNCTION
Intermittent wipe Short or open circuit of Delay value for setting 3 
the knurled wheel signal used.
Intermittent wipe Faulted Rain Sensor or K Bus Normal intermittent wipe 
with Rain Sensor Signal corrupt implemented
Wiper motor not Park contact feedback signal  Wiper motor control
functional moving takes longer than 16 seconds deactivated for 3 minutes 

ZKE - 21
LOWER TAILGATE COMPONENTS
BOWDEN CABLES
LATCH POSTS
LATCH MECHANISMS
LOWER TAILGATE
LATCH ACTUATOR 
ACTUATOR
MOUNTING PLATE
LOWER TAILGATE
ACTUATOR SWITCH
UPPER TAILGATE
LATCH POST
CABLE
LEVER
TAILGATE LOCK ACTUATORS
Each tailgate has  a separate latching/actuator system.  The upper tailgate actuator must first be
activated open before the lower tailgate actuator can be operated (program logic).
When  closed,  the  tailgate  actuator  position  switch  provides  a  ground  signal  to  the  GM
signifying  a  "closed  tailgate".    This  switch  also  serves  as  the  tailgate  open  signal  to
automatically switch the interior lights on.
The lower tailgate actuator operates a lever which pulls two bowden cables to unlatch the
outboard mounted latch mechanisms.  The upper and lower latch mechanisms can also be
manually unlatched for if electrical malfunction occurs (refer to complete vehicle section).