Sunroof Description and Operation
The tilt/slide sunroof consists of a moving glass panel and a
manual sunshade. In the tilt/slide sunroof system the rear of the
glass tilts up for venting and slides between the head liner and
roof panel as it slides open. The glass is controlled by an
integrated motor/controller. The sunshade has a mechanical
connection to the glass causing it to open with the glass and
keeping it from closing more than the glass.
The electrical portion of the tilt/slide sunroof system consists
of:
• |
Body control module
(BCM) |
• |
Sunroof glass control
module |
• |
Sunroof control switch
assembly |
• |
Vent control switch
assembly |
• |
Local interconnected network
(LIN-Bus) |
The sunroof electrical system uses a master/slave configuration
utilizing a LIN-Bus based system for communication. The BCM is
designated as the master, while the sunroof control module is
configured as the slave.
As the system master, the BCM uses the LIN-Bus communication bus
to enable or disable sunroof operation, communicate vehicle
information to the sunroof controller, and request sunroof
movement. The sunroof controller provides system status and
diagnostic information to the BCM for diagnostic reporting and
operational purposes.
The sunroof glass is controlled by a integrated motor/controller
containing the necessary electronics, motor, hall effect position
sensors, as well as the interface to the driver control switches.
The motor/controller is capable of controlling motion based on
control switch activation and LIN-Bus message commands from the
system master.
The operational calibrations for the sunroof integrated
motor/controller are loaded over the LIN-Bus communication bus by
the sunroof system master, the BCM.
Sunroof Glass and Sunshade Control Switches
The sunroof control switches are connected directly to the
controller. The sliding glass switches provide detent positions for
open, express open, off, close, and express close. The vent
switches provide detent positions for open, off, and close. The
control switch completes the circuit between two signals provided
by the control module, a reference ground input and a pull-up
voltage provided by an analog to digital switch input. The control
switches place a different resistor ladder network in the circuit
depending on the function selected. The controller's analog to
digital switch input reads the resulting voltage range and
determines the function as indicated in the included charts.
System Protection Functions
Normal operation of the sunroof system may be altered by one of
the following events.
Obstacle or Blockage Detection
When enabled, obstacle detection is active only while the sunroof
opening is approximately 4-200 mm (0.16-7.87 in) when moving
in the closing direction. When an obstacle is detected in this
range, the motion in the closing direction will stop and the
sunroof will reverse direction for a short distance. The reversal
shall complete regardless of operating Mode. If the travel is
outside the range defined above, the sunroof will try to continue
closing until it detects a motor stall condition or the system is
at one of it's defined stops.
Motor Stall
If the sunroof is moving in the open or close direction and stops
moving for 350 ms while the switch or LIN-Bus command is active,
and no obstacle has been detected, the motor shall be turned off to
prevent overheating.
Sunroof System Thermal Protection
The sunroof controllers have a thermal protection algorithm to
protect the sunroof controller and motor from damage due to
overheating conditions resulting from immoderately switch
actuations. The thermal protection algorithm will cause any new
sunroof open commands to be ignored until the motor is allowed to
cool. A number of close requests during an over temperature
condition will be allowed. If the thermal protection is triggered
during an obstacle detection event, the sunroof reversal shall be
finished.
Sunroof Operation
Vent - Open to Vent Position
When the sunroof is closed or in a partial vent position and the
sunroof vent open switch becomes active, the sunroof shall begin to
'Express open' to the vent position. sunroof motion shall cease
when the Sunroof reaches the vent position or if the sunroof
sliding glass switch becomes active.
Vent - Close from Vent
When the sunroof is in the vent position and the sunroof vent
switch enters the 'Close' state, the sunroof will begin to express
close the sunroof. Motion will continue until the sunroof has
reached its fully closed position or if the sunroof sliding glass
switch becomes active.
Sliding Class - Normal Open (Non-Express)
When the sunroof is not in a vent position and the sunroof sliding
glass switch is held in the 'Open' position, the sunroof will begin
opening. Motion will continue until the switch returns to the 'Off'
state or the vent switch transitions to any active state.
Sliding Class - Sunroof Express Open
When the sunroof control switch transitions to the 'Express Open'
state and the sunroof is not in a vent position, the sunroof will
express open until the controller determines the sunroof has
reached the comfort stop position or the fully 'Open' position, the
switch transitions to another state after first returning to the
'Off' position, or the vent switch transitions to an active state.
Sliding Class - Normal Close (Non-Express)
When the sunroof switch is in the 'Close' state and the sunroof is
not in the vent position, the controller will begin moving the
sunroof in the close direction. If the vent switch becomes active
the motor will be turned off.
Sliding Class - Sunroof Express Close
When the sunroof switch is in the 'Express Close' state and the
sunroof is not in a vent position, the sunroof will express close
until the controller determines the sunroof has reached the fully
closed position, or the switch transitions to another state after
first returning to the 'Off ' position. The sunroof motion will
cease if the switch transitions back to the 'Close' or 'Express
Close' state after returning to the 'Off ' position first or the
vent switch transitions to any active state.
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