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).