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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
615200133.tiff
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Mirror
Principle of Operation
The output stages and memory storage of mirror positions is handled by the respective
door modules. The positioning of the mirrors is signaled from the driver’s door switch
block/module. The signal passes over the P-Bus to the passenger’s door module.
The memory/recall for the driver’s mirror comes directly into the door module from the
memory switch. The operation for the passenger’s side mirror is carried out over the P-Bus
from the driver’s door module to the passenger’s door module.
The memory positions are stored in each respective module. The memory position is rec-
ognized by the feedback potentiometers located on each mirror motor.
The reverse gear tilt feature for the passenger’s mirror is signaled from the GM, over the P-
bus, when reverse is selected and the mirror switch is set for the driver’s side.
Mirror heating is controlled by each respective door module. The GM receives the outside
temperature from the IKE and passes it to the door modules. The “ON” time for mirror heat-
ing is adjusted based on the outside temperature.
A pulsed heating cycle is used for the mirrors based on the outside temperature.
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Central Body Electronics ZKE III
Temperature<-10OC -10 to 0OC 0 to 15OC 15 to 25OC >25OC
ON - duration 100% 75% 50% 25% 5%
E39 Shown
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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.
For example, the approximate E39 (528i) Battery draw is:
• 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 active (high) in the sleep mode.
Sleep Mode Criteria:
KL R, KL 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 signals listed below.
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Central Body Electronics ZKE III
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 “
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9. What type of sensor is used to detect the position of a seat with Memory? What type
of signal does it produce?__________________________________________________
_________________________________________________________________________
10. How does the Seat Module communicate a request for a stored memory position with
the mirror modules?_______________________________________________________
________________________________________________________________________
11. On an E38 with Servotronic, why is the speed signal provided to the GM from both
the IKE “A” signal and the K-Bus?___________________________________________
________________________________________________________________________
________________________________________________________________________
12. An E38 customer complains that when exiting the vehicle the steering wheel moves
up. What is the cause of this?______________________________________________
________________________________________________________________________
13. How does the SZM monitor the Seat Heating temperature?_____________________
________________________________________________________________________
________________________________________________________________________
14. What circuits are controlled by Consumer Cut Off? ____________________________
________________________________________________________________________
________________________________________________________________________
15. If a technician double locked a 2000 MY E39 while still inside the vehicle, how could
he/she exit the vehicle?____________________________________________________
________________________________________________________________________
________________________________________________________________________
16. How is the MY 2000 key charged?__________________________________________
________________________________________________________________________
________________________________________________________________________
17. How is the DWA Disarmed (emergency)?_____________________________________
________________________________________________________________________
18. What functions will deactivate the exterior door handle lighting? _________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
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Central Body Electronics ZKE III