2000 BMW 525i roof

Power Window Motors: The window motors are mounted on the cable regulators. The
window motor control circuit consists of two wires for operating the motor in both direc-
tions.
The motors are activated by relays in the GM of door
modules (front doors). The relays provide either power
or ground depending on the direction of window travel.
The GM controls the polarity of the motor based on a
request to run the window (window switch,
Convenience Opening/ Closing).
The windows are run to the limit stops which is detect-
ed by an amperage increase in the control circuit.
Additionally, the window run cycle is limited to a 6-8
second duration if in case the amperage increase is not
detected or there is a malfunction with the regulator.
Window Motor Limit Stop Function: If the windows are run up and down continuously
a limit stop function is activated to prevent the window motors from overheating. The GM
monitors the number of times the window motors are activated. Each cycle is counted and
stored in memory.
If the repetitive window activation (up/down) exceeds one minute, the GM deactivates the
internal relays and disregards any further input requests. The GM provides motor activation
after a short duration but not for the full one minute monitoring cycle. Over time, the GM
slowly reverses the stored count of activation until the stored number equals 0.
Convenience Opening/Closing: The GM provides the convenience open/close feature
providing control of the power windows (and sunroof) from outside the vehicle with the key
in the driver’s door lock cylinder. The FZV provides the same function for the opening only.
• The anti-trap feature is active during convenience closing from the driver’s door lock.
• The convenience open feature provides outside activation of the windows and sunroof
in the same manner.
• If the GM receives a request to operate convenience close or open for more than 110
seconds, the function is deactivated and a fault code is stored.
• The Car Memory Feature can activate and deactivate the Convenience Open Feature
from the FZV’s control.
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Central Body Electronics ZKE III
FRONT DOOR
REGULATOR
615200114.eps

Sunroof
Purpose of the System
When the ignition key is in accessory or “on”
position press the switch or slide it to the desired
direction to lift (2), open (1) or close the sunroof.
When lifting, the headliner retracts several inch-
es. The sunroof can continue to operate after
the ignition has been switched off as long as one
of the front doors has not been opened.
Mechanically, the sunroofs are similar in design.
Some vehicles are equipped with the steel roof
while others are equipped with the glass (moon)
roof.
The anti-trap feature of the sunroof uses a hall
sensor to detect obstructions while the sunroof
is closing. The initialization procedure must be
carried out to allow the sunroof to operate in the
opening direction and allow the anti-trap feature
to function.
The anti-trap is shut down 4mm
prior to full closed and during the tilt closing
function.
System Components
Sunroof Switch:Mounted in the sunroof motor trim cover, the switch provides coded
ground signals for system operation. The following signals are generated over three wires:
• Rest position.
• Slide open request (press and hold switch - first detent of
open position).
• Automatic slide open request (press further to second
detent and release).
• Tilt open (press and hold).
• Slide close request (press and hold switch - first detent of
close direction).
• Automatic slide close request (press further to second
detent and release).
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Central Body Electronics ZKE III

Sunroof Motor/Module (SHD): The motor is powered to open, close and lift the sunroof
panel. The motor contains two hall effect sensors that monitor the motor shaft rotation pro-
viding sunroof panel position.
The hall sensors also provide the end limit cut
out function for the SHD once the system is ini-
tialized. The SHD counts the pulses and cuts
the motor out prior to the detected end run of
the sunroof panel.
The combined motor module has a pin con-
nector for interfacing the switch, and vehicle
harness (power, ground and Bus.)
The electronic controls and relays are contained in the sunroof module (PM-SHD). The
module is connected to the P-Bus (E38 >99 MY on the K-Bus) for comfort closing/open-
ing and diagnosis/fault memory purposes.
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Central Body Electronics ZKE III
System Components: Inputs - Processing - Outputs
/K-BUS

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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Central Body Electronics ZKE III

Workshop Hints
SHD Self Diagnosis
The SHD monitors operation and stores fault codes if a defect is determined. The SHD
monitors the following conditions:
• SHD motor relays:The relays are checked for sticking contacts (plausibility) and non
functional contacts.
• Hall effect position sensors:The SHD must detect a pulse frequency from the hall
effect sensor(s) during operation.
• Sunroof Switch: The SHD monitors the signal plausibility of the coded signaling from
the sunroof switch.
Sunroof Fault Response Characteristics
If a fault occurs with any of these functions, the SHD responds as follows:
• Overrides the end run detection.
• Switches the motor off if the relay contacts stick for more than 500 ms.
• Switches the motor off if pulses are not received.
Emergency Operation of the Sunroof
If the sunroof motor does not respond to the switch signals, the hex key in the trunk lid tool
kit is used to manually turn the motor shaft drive.
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Central Body Electronics ZKE III

Review Questions
1. List the functions directly controlled by the GM III._______________________________
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2. How does the GM III communicate with other control modules?__________________
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3. What effect does road speed have on the wiper system? What effect does it have on
an AIC equipped vehicle? Where does the road speed come from?_______________
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4. How does the GM III recognize the key position from the drivers door?____________
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5. Describe the procedure used by the GM III to recognize an FZV key. Can the GM
differentiate between different keys? How many can it recognize?________________
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6. What “convenience” features are available from the FZV key?____________________
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7. Describe what happens when the GM receives the crash signal from the MRS.
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8. Why does the SHD (sunroof) module require initialization but the windows do not?
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Central Body Electronics ZKE III