
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 

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   

ZKE - 14
CENTRAL LOCKING
SYSTEM FEATURES:
• The  Central  Locking  system  controls  the  door  locks,  tailgate  locks  and  Fuel  Filler  Flap
actuators.  
• The  familiar  single/double  locking  strategy  is  maintained  from  previous  systems  with  a
new style door lock mechanismcombined with dual actuator motors similar to that
of the E46 ZKE V system. 
• The automatic locking feature  activates  the  door  lock  actuators  when  a  road  speed
signal  of    7.5  MPH  is  detected  via  the  K-Bus.    The  factory  default  encoding  of  this
feature is off, but can be encoded on for individual users with the Key Memory function.
• The Driver’s door lock location is the only point outside of the vehicle where the key can
mechanically  control  the  central  locking  system  functions.  The  lock  incorporates  the
familiar overrunning lock cylinder that breaks away and freewheels if an attempt is made
to destroy the lock with a screwdriver,  dent puller, etc. 
• The selective unlocking feature is maintained.  A single unlock request from the driver’s
door with the key or via the remote transmitter unlocks the driver’s door only.  A second
unlock  request  unlocks  the  remaining  doors  and  trunk.      This  feature  can  be  modified
for  individual  users  with  the  new  Key  Memory  capabilities  to  activate  all  lock  actuators
simultaneously. 
• When unlocked, the X5 uppertailgate can be opened by:
- the tailgate button in the center console SZM, 
- trunk release switch pad located above the license plate, or
- the trunk release button on an FZV key.
• With the upper tailgate open, the lower tailgate is then opened by depressing the switch
located along it’s top edge.
• GM  and  EWS  3.3  interface  via  the  K  bus  to  monitor  double  lock  status  and  to  initiate
double lock override.  This feature allows the doors to be opened from the inside if an
accepted EWS key is switched on in the ignition when double locked.   

DOOR LOCK ACTUATORS
The  actuators  are  sealed,  self  contained  units  with  no
replaceable parts.  The door lock actuators use hall effect
sensors to provide:
• Door lock key position (driver’s door only),
• Door open/closed status.
The driver’s door lock provides the following signals to
the driver’s door switchblock module (PM-FT/SB):
• Lock / Unlock,
• DWA arm/disarm 
• Convenience closing and opening signals.
DOOR LOCK POSITION HALL
SENSORS
The  Drivers  door  switchblock
module monitors these key positions
over  two  wires.    The  signals  are
generated by two hall effect sensors
(Hall  Sensor  1  &  2)  located  in  the
actuator. 
When  the  key  is  turned,  a  plastic
cylinder  in  the  lock  actuator  is
simultaneously  rotated  by  the  lock
tumbler extension rod.  
A  magnet  is  incorporated  in  the
plastic  cylinder,  which  when  rotated
changes  the  magnetic  influence  on
the hall sensors.
The  presence  of  a  magnet  in  close
proximity  to  the  sensing  surface  of
either  hall  sensor  creates  a  coded
input over the two wires that the GM
uses to determine the key position.
• Magnet in front of sensor, current flow through the sensor is <5 mA (0). 
• Magnet rotated away from sensor, current flow through the sensor is >12 mA (1).
Hall sensor 1 & 2 are not included in the front passenger door or rear door actuators.
ZKE - 16
NEUTRAL
- 0 -
MANUAL
LOCK
HALL SENSOR 1
MANUAL
UNLOCK
• DOUBLE LOCK
 DWA ARMED
 CONVENIENCE
CLOSING (hold
until activated). UNLOCK
 DWA DISARMED
 CONVENIENCE
OPENING (hold
until activated).
HALL
SENSOR 2
TUMBLER
EXTENSION ROD
PLASTIC CYLINDER WITH ASYMMETRICAL MAGNET
(Shown in the Lock Position)    

ZKE - 18
ACTUATOR MOTOR CONTROL
There are two motors incorporated in each actuator that provide two separate functions:
•Single lock/unlock function.  This  motor  controls  the  mechanical  lock  mechanism
when  the  central  lock  button  is  pressed  to  single  lock  the  vehicle.    The  mechanism  is
locked at this point but can by opened from the interior by pulling an interior door handle
twice or  by  pressing  the  central  lock  button  again.    When  single  lock  function  is
activated, the fuel filler flap actuator is not locked.
•Double lock/unlock function. This motor is activated only when the vehicle is locked
from  the  outside  at  the  driver’s  door  lock  with  a  key  or  when  the  GM  receives  a  lock
request  from  the  FZV  system.      In  this  case  the  double  lock  motor  is  activated
simultaneously  with  the  single  lock  motor.    The  function  of  the  double  lock  motor  is  to
mechanically  offset  an  internal  rod  disabling  it  from  unlocking  the  vehicle  from  the
interior.    This  prevents  the  doors  from  being  unlocked  by  any  means  except  from  an
unlock request at the driver’s door, the FZV remote key or via central lock button.
• Continuous locking/unlocking will initiate a timed arrest of the locking system. The GM counts
each  time  the  locks  are  actuated.  After  approximately  12  cycles,  the  timed  arrest  is  active.
The  timed  arrest  is  deactivated  one  actuator  cycle  for  every  8  seconds  until  the  counter  is
reset to 0. The timed arrest is overridden if a crash signal is received from the MRS III.  

All door lock actuators and the fuel filler flap actuator are controlled directly by the GM via
four  internal  load  relays.    The  drivers  door  lock  actuator  has  a  separate  circuit  for  the
selective unlocking feature.
If this feature is disabled by key  memory encoding, the driver’s door lock actuator selective
unlock circuit is activated simultaneously with the balance of the motors during unlock.
CONTROL DURING DOUBLE LOCK:
CONTROL DURING SINGLE LOCK:
SELECTIVE SINGLE LOCK
- CONTROL - SWITCHED POWER -
SINGLE LOCK CONTROL
- SWITCHED POWER -
GROUND
DOUBLE LOCK CONTROL
-SWITCHED POWER-
FUEL
FILLER
FLAP
LEFT
REAR
DOORRIGHT
REAR
DOORPASS.
DOORDRIVER’S
DOOR
SELECTIVE SINGLE UNLOCK
- SWITCHED GROUND -
SINGLE UNLOCK CONTROL  
- SWITCHED GROUND -
UNLOCK CONTROL
- SWITCHED POWER -
DOUBLE LOCK CONTROL
-GROUND-
FUEL
FILLER
FLAP
LEFT
REAR
DOORRIGHT
REAR
DOORPASS.
DOORDRIVER’S
DOOR
SELECTIVE SINGLE LOCK
- CONTROL - SWITCHED POWER -
SINGLE LOCK CONTROL
- SWITCHED POWER -
GROUND
NOT ACTIVE
FUEL
FILLER
FLAP
LEFT
REAR
DOORRIGHT
REAR
DOORPASS.
DOORDRIVER’S
DOOR
ZKE - 19
CONTROL DURING SINGLE UNLOCK:       

TAILGATE CONTROL
The tailgate can be opened from the following locations:
• Exterior tailgate switch pad above the license plate
• Interior remote tailgate button 
• FZV radio key
The  remote  tailgate  button  is  locked  out  when  the  GM
detects  a  vehicle  speed  signal  >  4  MPH  via  the  K-bus.
The switch has been incorporated into the SZM.
ZKE - 20