2006 BMW X5 Central Body Electronics Workshop Manual

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.
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STEERING COLUMN OPERATION
The adjustable steering column is similar to the E38 in components, mechan-
ical linkages and electrical operation. The steering column adjusting switch is
mounted on the left side of the steering column and provides for four directions
of column movement.
The motors for tilt and length also employ ripple counter modules for motor control and
memory recall. The control electronics for the steering column are integrated into the seat
module. The steering column switch inputs are processed by the seat module and the out-
put signals are sent to the steering column ripple counter modules for motor activation.
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RIPPLE
COUNTER

STEERING COLUMN MOTOR DRIVES
Forward/Back (Telescope)
A flexible drive shaft operates a screw drive which causes a forward/back movement of the
steering column.
Up/Down
A flexible drive shaft moves an off-center lever causing up/down steering movement.
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GENERAL FUNCTIONS OF ZKE III
CONSUMER CUT OFF
The interior lights are connected to the consumer cut out circuit. These consumers are con-
nected to KL 30 and can remain on if one of the control switches are left on. This would
prevent the ZKE from going into the sleep mode. However, the consumer cut off will switch
Kl 30, to the interior lighting, off after 16 minutes.
OVERLOAD PROTECTION
The seat and steering column motors are provided operating power through the consumer
cutoff / overload protection relay module as on the E38. The consumer cutoff signal from
the GM signals the relay to maintain operating power to the consumers.
If an overload condition exists, the relay module detects the increase in amperage and
opens the relay. The relay module is located in the electrical carrier forward of the glove
box.
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SLEEP MODE
To lower the constant battery draw when the vehicle is parked, The complete ZKE system
will go into the “Sleep Mode” 16 minutes after the ignition has been switched off and no
further ZKE function is active.
Approximate X5 Battery draw: • Ignition switch off = approx 750 mA.
• One minute after = approx. 560 mA.
• After 16 minutes (sleep mode) = approx. 18 mA.
All modules in the ZKE system will go into the sleep mode. The P-Bus remains active, how-
ever no data transfer takes place until a wake-up request is received. The general module,
door modules or keyless remote module can wake the system up and put the ZKE back
on line. The K-Bus is not active in the sleep mode, however the GM III of Remote Entry
Module can put the K-Bus back on-line with a wake-up request.
SLEEP MODE CRITERIA: KL R, 15 OFF and no further function activated for 16 minutes.
WAKE UP CRITERIA: KL R or 15 “ON” or a change in one of the signal states listed below.
SIGNAL ACTIVITY ORIGINATING
MODULE
K-BUS High General Module
Door jamb switches (possibility of 4) Low “
Trunk lid lock cylinder microswitch High “
Trunk lid pushbutton microswitch Low “
Interior Trunk lid pushbutton microswitch Low “
Central locking button Low “
Hood microswitch Low “
Trunk Lid microswitch Low “
Interior light switch Low “
FIS sensor Low “
Tilt Alarm sensor Low “
FBZV operational signal High FBZV Module
Driver’s door lock microswitch - (lock) High PM-FT/SB
““““ - (unlock) High “
Passenger door lock microswitch - (lock) High PM-BT
““““ - (unlock) High “
Tailgate
Tailgate
Tailgate
Tailgate
UIS

DIAGNOSIS/TROUBLESHOOTING
The GM III contains an EEPROM fault memory. Faults that occur with any of the sub-sys-
tems of the ZKE are stored in the GM III. Diagnosis and troubleshooting is carried out with
the DIS tester. The diagnostic link is through the IKE or Instrument cluster over the K bus
to the GM.
Additional sub-fault memories are incorporated in all of the peripheral modules. The infor-
mation stored in these location is used to pin point defective components.
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BASIC TROUBLESHOOTING
• Always personally verify the customer complaint.
• Always verify that the complaint is truly a system malfunction.
• Perform a Quick Test to determine if the vehicle systems have logged fault codes.
• Call up the faulted system or appropriate test schedule to verify the correct control
module is installed in the car.
• Follow the Diagnostic Information System (DIS) on screen instructions and perform all
tests as specified.
• Use the DIS and fault symptom diagnostic procedures as trained.
• Follow the appropriate test module procedures for systems that malfunction but fail to
set faults in memory.
• System problems which elude diagnostic procedures must be brought to the attention
of BMW of North America, Inc.
•BMW Technical Assistance Hotline 1-800-472-7222
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