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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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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
Page 51 of 80

Interior Lighting
Purpose of the System
The GM controls the interior lighting automatical-
ly with the status change of several monitored
inputs. The lighting can also be manually con-
trolled using the interior light switch.
In addition to the various time controls, the inte-
rior lights are also subject to the 16 minute shut
down of the GM (consumer protection).
Principle of Operation
The interior light switch is a push button switch that will carry out the opposite command
of the current status of the lights. (ie: if the interior lights are currently on, pushing the but-
ton will switch the lights off.)
• If the interior lights are switched “ON” by the button with the ignition switched ON, the
interior lights will remain on until they are switched off by the button.
• If the interior lights are switched “ON” when the ignition is switched OFF, the lights will
remain on for 16 minutes (consumer cutout).
• Pressing the interior light button for longer than three seconds will switch the lights to
continuous off. This feature is intended for workshop use.
Pressing the button again will
return the lights to the normal operational status.
• Locking the vehicle from the outside will immediately switch off the interior lights.
The ON/OFF conditions for the interior lights in the automatic mode are as follows:
ON Conditions
• Door Open.
• Switching off ignition after exterior
lights have been switched off.
• MRS Control Module crash input.
• Unlocking with FZV or pressing FZV
lock button when the vehicle is
already locked (interior search fution).
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Central Body Electronics ZKE III
OFF Conditions
• All doors closed with ignition on.
• All doors closed with ignition off after 20
seconds.
• 20 seconds after switching off ignition with
lights off.
• 8 seconds after remote control activation.
• 16 minutes with door(s) open.
• When doors are locked.
Page 52 of 80
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Central Body Electronics ZKE III
System Components: Inputs - Processing - Outputs
615200119.eps
Page 53 of 80

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.
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Page 54 of 80

Rear Seat Interior/Reading Light Units: In
each C pillar trim panel is an interior/reading light
unit.
These units each contain an interior light that is
controlled with the front interior light and a
mechanically switched reading light on the con-
sumer cut off circuit.
Front Footwell Lights: In each front footwell,
there is also a courtesy light. These lights are
only operated when the GM provides power to
the interior lighting circuit.
On E38 and E53 the doors also contain courtesy
lights at the lower edge of the door panel (1).
Door Warning Lights (E38): The additional
“red” warning lights are installed in the edge of
the doors (2). These lights are illuminated when
the doors are opened.
Illuminated Transmission Shift Indicator
(E38): The E38 uses a microprocessor for dis-
playing the shifter position in the center console.
The processor receives shift position signals
from a console mounted range switch. The
processor illuminates the LED corresponding to
the position of the range selector.
The park position LED will remain “on” after the
ignition is switched off and stay on until the GM
goes into the “sleep” mode.
Soft Lighting Feature: The GM provides progressive voltage (up to 12v) providing the soft
on feature
to the interior lighting circuit when the interior lights are required. The GM grad-
ually reduces the full 12 volt power supply providing soft off
when interior light deactivation
is required.
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Central Body Electronics ZKE III
Park
Position
LED
Page 55 of 80

Visual Entry Aid (E38/E53)
Purpose of the System
The E38 (>99 MY) and E53 is equipped with the “Visual Entry Aid” lighting system which
enhances operator convenience and safety. All interior door handles are supplemented with
soft glow lighting for ease of locating the interior door handles. When activated, the exteri-
or door lighting illuminates providing a subtle underglow for the exterior door handles on
the E38 and exterior rear view mirrors on the E53.
• The interior door handle lighting(including later E53) is provided by slim profile LEDs
and controlled directly by the LCM III.
• The exterior door handle lightingis provided by halogen bulb light sources in each
door and fiber optic tubing. The light sources are controlled by a Visual Entry Aid Control
Module which activates the lights simultaneously when the GM III activates the vehicle
interior lights.
System Components
Interior Door Handle Lighting: The light-
ing is provided by orange glow light strips
illuminated by LED’s.
• The light strips are part of the door han-
dle shell and are not replaceable.
• The LED’s are individually replaceable.
The LED’s are connected to the KL 58g interior panel lighting circuit. KL 58g is an output
pulse width modulated control signal from the LCM III. The duty cycle changes when the
LCM III detects a change in the voltage drop at the light dimmer input signal.
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Central Body Electronics ZKE III
Replacement LED
“Orange Glow”
Light Strip
615200121.eps
Page 56 of 80
Exterior Door Handle Lighting: The Visual
Entry Aid Control Module is located in the elec-
trical carrier forward of the glovebox.
To control the system, the Visual Entry Aid con-
trol module requires:
• KL 30
• KL 15
• KL 31
• Interior Light control signal (GM Output)
The GM controls the soft on/off feature of the vehicle interior lights by a pulse width mod-
ulated control signal. This signal is also an input to the Visual Entry Aid control module
which requests simultaneously control (soft on/off) each exterior door light source.
Light Source Modules: Mounted in each door
are the light source modules.
The light source modules are made up of the
housing, halogen bulb and reflector. The reflec-
tor holds the bulb and focus the bulbs light into
the housing.
The bulbs are are available for individual replace-
ment.
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Central Body Electronics ZKE III
CONTROL MODULE
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