seat adjustment BMW X5 2002 E53 Central Body Electronics Workshop Manual

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

Car Memory / Key Memory
The Car/Key Memory feature provides the flexibility of allowing the owner to customize cer-
tain 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).
Car & Key memory is marketed as a combined feature but is actually two separate func-
tions of the select vehicle control systems.
Car Memory: The owner is provided with a list of available system functions that can be
customized to their liking. Prior to delivery, the DIS 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 DIS 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 vehicle.
Units DisplayChange (ºF/ ºC)
• DWA - Features
• FZV - Features
• Automatic Seat
Adjustment
• Method Selection
• Recirc
Air Memory
• Daytime Running
Lights
• Home Lights
UNLEADED GASOLINE ONLY01
220km/hMPH1/min
x1000
40 6080100120
140
160
180
200
220
240
1
023
4
5
6
75030
20
15
1220 406080
100
120
1401
1
MoDiC
20 PIN
DIAGNOSTIC
CONNECTION
MoDiC
D-BUS
DIS
A
SEAT
MODULE
GMV
IHKA
LSZ

ZKE - 28
LCM III
GM III

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 V 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.
ZKE - 29

SEAT OPERATION
Each motor for seat adjustment contains a micro-processor (called a Ripple Counter) that
receives a digital signal from the seat control module for motor activation. The motors are
connected to KL 30 and KL 31 and respond to the signals generated by the seat module
when seat movement is requested. The seat adjustment switch provides ground input sig-
nals to the module when seat movement is desired. The module processes these input sig-
nals and sends output signals to the seat motor processors. The seat motor processors
activate the motors and the seat moves to the desired point.
The circuitry of the Ripple Counter detects the motor activation current. As the armature
segments of the motor rotate passed the brushes, the current flow rises and falls produc-
ing a ripple effect. The peaks of these ripples are counted and stored in the Ripple Counter
module. The memory function of the seat module uses this ripple count instead of feed-
back potentiometers to memorize and recall seat positions.
RIPPLE COUNT RECOGNITION
When the seat is installed and the battery is connected, the ripple counter uses the initial
position of the motors as the “Zero Position”. Any movement from this point is counted as
“+” or “-” pulses as the motors move in either direction. The pulse position of the motors
is stored in the seat module, in an EEPROM, before the ZKE goes into its “Sleep Mode”.
This prevents the position recognition from being lost. If the battery is disconnected before
the 16 minute sleep mode activation, the memory positions of the seat will be lost and
reprogramming will be required.
ZKE -57