seat memory BMW 740IL 1996 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: _______________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
28
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

Seat/Mirror/Steering Column Memory
Purpose of the System
The front seats, outside rearview mirrors and steering column (if equipped) positions are
electrically adjustable. The “customized” adjustment positions can be memorized and
stored for three diferent users and recalled back to the individual positions (with the excep-
tion of the passenger seat - not in memory).
The basic features of seat/mirror/steering column operation, as well as the memory posi-
tions is integrated into the ZKE III system.
• Seat/Steering Column Memory
Module (PM SM).
• Driver’s Door Switchblock Mod-
ule (PM FT/SB - early E38 was
separate).
• Passenger’s Door Module (PM
BT - E53 combined with window
switch).
• General Module (GM III).
• 3 Position Memory Switch.
• Seat Switch.
• Steering Column Switch.
• Seat/Steering Column/Mirror
Motors.
The Seat/Steering Column Memory Module communicates with the DISplus or MoDiC for
diagnosis and Vehicle Memory encoding.
58
Central Body Electronics ZKE III
System Components: Inputs - Processing - Outputs
E38/E39 Shown

59
Central Body Electronics ZKE III
System Components
- with Principle of Operation
Manual Operation:The manual adjustments of the seat, mirrors and steering column are
carried out with the respective switches as with the previous systems.
The mirror adjustment switch is located in the driver’s switch block. The mirror operation
input is a digital signal that is processed by each respective module for mirror positioning.
Memory Storage: The parameters for storing memory positions are are as follows:
• With the transmission range
selector in “P” and the mirror
change over switched to the left,
switch the ignition on and press
the “M” on the memory switch.
• The memory indicator lamp swi-
tches on for 7 seconds.
• Press one of the three position
switches (1, 2 or 3) within the 7
second memory period.
• The current positions of the mir-
rors, seat and steering column
are stored for recall.
The positions of the mirrors are stored in the respective door
modules based on the position of the feedback potentiome-
ters. The positions of the seat and steering column are stored
in the seat module, based on the ripple count.
Recalling a memory position setting is possible by either
pressing and holding the recall switch (1, 2 or 3) with KL 15
“ON” or tapping the recall button (1, 2 or 3) with:
• The driver’s door open and KL 15 “OFF”.
• KL R ON and KL 15 “OFF”.
The recall movement can be interrupted at any time by touching any of the adjusting
switches.
E38/E39
E53
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