Seat BMW 750IL 2001 E38 Central Body Electronics ZKE Manual

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

2
Central Body Electronics ZKE III
Objectives of the Module
After completing this module, you will be able to:
• List the functions directly controlled by the GM III.
• Describe how the GM III recognizes the key position from the drivers door.
• Explain what “convenience” features are available from the FZV key.
• Describe how the Seat Module communicates a request for a stored memory position
with the mirror modules.
• List what circuits are controlled by Consumer Cut Off.
• Demonstrate how to Emergency disarm DWA.
• Describe the changes in the 2000 MY Key.
• Explain the electronic influence on power steering assist (Servotronic).
• Demonstrate how to open the sunroof (in the event of an electrical malfunction).
CENTRAL BODY ELECTRONICS (ZKE III)
Models: E38 - 740i(L) and 750iL
E39 - 525i, 528i, 530i, 540i and M5
E53 - X5 3.0i and X5 4.4i
Production Date: E38 1994 to Present
E39 1997 to Present
E53 1999 to Present
Manufacturer: Hella
Pin Connectors: White - 26 pin, Black 26 pin, Black 20 pin (large)

3
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).

5
Central Body Electronics ZKE III
The ZKE III system offers an overall reduction in vehicle wiring particularly in the areas sub-
ject to wear from movement such as doors, seats and the steering column. To accomplish
this, the “P- Bus” is used to interface (signaling) with peripheral modules over a single wire.
The ZKE III modular system consisting of the following components:
• General Module III = Main controller for ZKE functions
• PM - SB/FT = Driver’s door switch block and door module
• PM - BT = Passenger’s door module
• PM - SHD =Sunroof module
•PM - SM =Seat/Mirror/Steering Column memory module
• AIC = Rain Sensor (if equipped)
All modules communicate through the P-Bus and GM III onto the K-Bus for diagnosis.
PM-FT/SB
PM-SMPM-BT
PM-SHD
P-BUS
K-BUS
Driver's Door
Switchblock/
ModuleDriver's Door
Switchblock/
Module
Seat Memory
ModuleSeat Memory
Module
Passenger's
Door ModulePassenger's
Door Module
Sunroof
ModuleSunroof
Module
GM IIIFBZVFBZVDWADWA
FBZV
RECEIVER
MODULE
GM III MODULE
LOCATED IN CARRIER
FORWARD OF GLOVE BOX
Separate
Switch and
Module < 96
E38 on K-Bus
>99 MY
12520102.eps

6
Central Body Electronics ZKE III
The following is an overview of new or changed features found on the E53 ZKE III variant:
• Passenger’s door module is incorporated into the passenger’s door switchblock.
• Sunroof module (SHD) is located on the P -Bus.
• The Central Locking system uses a door lock actuators with hall effect sensors.
• The GM III is responsible for the Key Memory feature.
The E53 ZKE III system continues to be a modular system consisting of the following:
•General Module III = Main controller for ZKE functions
•PM - SB/FT = Driver’s door switch block and door module
•PM - SB/BT =Passenger’s door module/Window switch
•PM - SHD =Sunroof module
•PM - SM =Seat/Mirror/ Steering Column memory module
•AIC = Rain Sensor (if equipped)
All of these modules communicate over the “K-Bus and P-Bus” for signaling purposes and
diagnosis.

The Remote Entry System incorporated minor changes since the original introduction
which includes:
• The control electronics are incorporated into the GM III.
• The antenna is incorporated into the rear window lower heater grid.
• The remote key receiver is installed in the left “C” pillar. The receiver produces a digital
signal based on the transmitter command and sends it to the GM for processing. The GM
then carries out all remote entry operations either directly or through the door modules
for the front doors. The frequency at which the key transmits the radio signal to the ant-
enna amplifier is 315 MHz.
Vehicle/Key Memory
The Vehicle/Key Memory feature provides the flexibility of allowing the owner to customize
certain functions of select vehicle systems and automatically identifies users of the vehicle
by a key identification signal provided by the remote keyless entry system (FZV).
Vehicle & Key memory is marketed as a combined feature but is actually two separate func-
tions of the select vehicle control systems.
27
Central Body Electronics ZKE III
A
IHKA
K-BUSKEY #1
KEY #2
KEY #3
KEY #4
GMV
SM
Adjust Setting of Seat
For Key #1 IHKA Features Key #1
Being Used
KEY 4
KEY 3
KEY 2
KEY 1
KEY 1
- Selective Unlocking
- Automatic Locking
615200099.eps

Vehicle Memory: The owner is provided with a list of available system functions that can
be customized to their liking. Prior to delivery, the DISplus or MoDiC is used to encode the
owner’s chosen selections into the appropriate control modules.
These choices become a permanent function of the control module and can only be
changed by re-encoding with the DISplus or MoDiC at a BMW Center.
This feature has been available for some time via the ZCS Conversion Feature but has
never been fully utilized or officially presented to the vehicle owner as a feature of their vehi-
cle.
Key Memory: This feature provides the added convenience of identifying users of the vehi-
cle whenever a lock or unlocked signal is generated via the individual FZV keys. A maxi-
mum of four FZV keys can be used with the Key Memory feature.
Each of the four keys generate a unique key identification signal (key number) that is trans-
mitted simultaneously with the lock/unlock signals to the General Module. Key Memory
does not respond to Lock/Unlock requests from the drivers door lock.
Mostof the key memory functions require the vehicle be configured using the “KEY MEM-
ORY” function of the DIS or MoDiC. However, there are a few features that store settings
automatically without configuration such as IHKA blower speed and temp setting. The key
ID signal alerts the GM to communicate with select control systems over the K Bus to store
(when locked) or reset (when unlocked) certain driver adjustable settings.
There are features that function as both a Car & Key Memory feature.
Example; the Automatic Seat Adjustment feature is encoded as a Car Memory Function
with the following possibilities:
• When unlocking,
• When opening a door after unlocking
• Or not active at all.
If active, the seat positions are stored and reactivated by the Key Memory function for indi-
vidual users of the car.
Notes: _______________________________________________________________________
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28
Central Body Electronics ZKE III

Principle of Operation
Initialization: Initialization is required for the SHD to learn the end positions of the motor's
travel. The hall sensors provide pulses for motor rotation, the SHD counts the pulses and
determines where the panel is by memorizing the stored pulses.
If the system is not initialized, the sunroof will only operate in the tilt up and slide close posi-
tions. Initialize as follows:
• Press and hold the sunroof switch in either the tilt up or slide close positions for 15 sec-
onds.
• The sunroof motor operates momentarily signifying initialization acceptance.
The SHD memorizes the pulses from the hall sensors on the next activation of the motor
by driving the panel to its end run positions. The SHD senses an amperage increase and
determines the end run position. The counted number of pulses is then used as the basis
for calculating the panel position.
Anti-Trap Feature: The anti-trap feature of the sunroof uses a hall sensor to detect
obstructions while the sunroof is closing (pulse frequency slowed down) in the automatic
close function. The anti-trap feature is shut down prior to full closing (4mm from full closed)
to allow the sunroof to seat into the seal.
Note: The anti-trap feature is not functional when the switch is held in the manual close
position.
Notes: _______________________________________________________________________
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49
Central Body Electronics ZKE III

System Components
Door Contacts: As mentioned in the Central Locking Section, the existing door contacts
opened/closed are also an input for the interior lighting function. The E53 uses the Hall
effect sensors for the purpose of monitoring door open/closed status (located directly
behind the rotary latch plate encased in the actuator). The sensor is activated by the rotary
latch plate's position.
• Door closed, the rotary latch plate is in the latched position. Current flow through the
hall sensor is < 5 mA.
• Door open, the rotary latch plate is in the open position. Current flow through the hall
sensor is > 12 mA.
A change in current flow informs the General module when a door is opened or closed.
Front Seat Interior/Map Light Unit:The overhead front seat interior light unit contains a
single main interior light. The light is controlled by the GM automatically or by momentarily
pressing interior light switch located on the light assembly.
The switch provides a momentary ground signal that the GM recognizes as a request to
either turn the light on (if off) or turn the light off (if on).
If the switch is held for more than 3 seconds, the
GM interprets the continuous ground signal as a
request to turn the interior light circuit off for the
Workshop Mode
.
The workshop mode is stored in memory and
will not come back on even if the GM is removed
from it's power supply and reconnected. The
switch must be pressed to turn the lights back
on.
There are two reading/map lights also located in the assembly. Each map light is mechan-
ically controlled by depressing the corresponding on/off switch. The power supply for the
map lights is supplied by the GM through the Consumer Cut Off circuit.
53
Central Body Electronics ZKE III

Rear Seat Interior/Reading Light Units: In
each C pillar trim panel is an interior/reading light
unit.
These units each contain an interior light that is
controlled with the front interior light and a
mechanically switched reading light on the con-
sumer cut off circuit.
Front Footwell Lights: In each front footwell,
there is also a courtesy light. These lights are
only operated when the GM provides power to
the interior lighting circuit.
On E38 and E53 the doors also contain courtesy
lights at the lower edge of the door panel (1).
Door Warning Lights (E38): The additional
“red” warning lights are installed in the edge of
the doors (2). These lights are illuminated when
the doors are opened.
Illuminated Transmission Shift Indicator
(E38): The E38 uses a microprocessor for dis-
playing the shifter position in the center console.
The processor receives shift position signals
from a console mounted range switch. The
processor illuminates the LED corresponding to
the position of the range selector.
The park position LED will remain “on” after the
ignition is switched off and stay on until the GM
goes into the “sleep” mode.
Soft Lighting Feature: The GM provides progressive voltage (up to 12v) providing the soft
on feature
to the interior lighting circuit when the interior lights are required. The GM grad-
ually reduces the full 12 volt power supply providing soft off
when interior light deactivation
is required.
54
Central Body Electronics ZKE III
Park
Position
LED