Power Sunroof System Components
The power sunroof system consists of the following components:
• | Sunroof motor assembly, with limit switch |
• | Sunroof glass panel tilt slide type, with glass sliding between
roof and headliner |
• | Rail and track assembly upon which the sunroof glass rides |
• | Power supply for the sunroof module: SUNRF fuse 20 A |
Power Sunroof Operation
The overhead console has a sunroof switch that controls both the vent
and slide open options.
The sunroof glass may be moved by the use of the sunroof switch to any
of the following positions:
• | Partially open in either slide open or vent positions |
The sunroof module contains the logic for the opening and the closing
of the sunroof based on the sunroof switch and the limit switch. The sunroof
motor assembly contains the reversible DC drive motor, the gear train, and
the limit switch.
The sunroof module determines sunroof motor direction based on inputs
received from the sunroof switch. When the ignition switch is in the ON position
or when Retained Accessory Power RAP is active, voltage is applied to the
sunroof module via the (RAP) system. For a description and operation of
the RAP system, refer to
Retained Accessory Power (RAP) Description and Operation
in Retained Accessory Power. The
sunroof module controls sunroof motor direction by changing the polarity
of the applied voltage. The sunroof module remembers the sunroof position
whenever the ignition switch is turned to the OFF position. The limit switch
is used to tell the sunroof module that the glass is parallel to the roof.
The limit switch only supplies open circuits or grounds to the module. An
internal pull-up resistor in the sunroof module, connected to battery voltage,
supplies the voltage at each input when the switch contacts are open.
Express Open
The sunroof may be opened to this position by pressing and releasing
the sunroof switch to the rearward position. This will apply the sunroof
switch low reference circuit to the sunroof switch open signal circuit 12 volt
reference input, pulling the reference voltage to 0 volts. The sunroof
module seeing the 0 volt input, will apply voltage to the motor outputs,
automatically sliding the sunroof glass and sunshade to the fully open position
and allowing the wind deflector to raise upward. The motor will slide the
sunroof glass until:
• | The sunroof glass reaches a hard stop, that causes motor internal
circuit breaker to open, stopping the motor. |
• | The sunroof switch is pressed again in any direction. |
Closing Sunroof from the Open Position
Closing the sunroof from the open position, the sunroof switch must
be pressed and held forward until closed. As the close mode is initiated,
the sunroof switch low reference circuit is applied to both the sunroof
switch open vent signal circuit 12 volt reference and sunroof switch
vent signal circuit 12 volt reference inputs, pulling them to 0 volts.
As long as the sunroof switch is held to the close position the sunroof
module will control voltage to the motor outputs to slide the glass to the
closed position. The motor will run until the sunroof limit switch closes,
applying the sunroof limit switch low reference circuit to the sunroof limit
switch soft stop signal circuit 12 volt reference input, pulling
the reference voltage to 0 volts, indicating the closed position
has been reached. The wind deflector will retract prior to the sunroof glass
reaching the fully closed position. To close the sunshade, this will have
to be manually slid forward.
Opening Sunroof to the Full Vent Open Position
The vent open mode is initiated by pressing and held upward on the front
portion of the sunroof switch. This will constantly apply the sunroof switch
low reference circuit to the sunroof switch open vent signal circuit 12 volt
reference input, pulling the reference voltage to 0 volts. As the
sunroof module sees the constant input, it will apply voltage to the motor
outputs, raising the rear of the sunroof glass to the full vent position.
The motor will tilt the rear of the glass upward until it reaches a hard
stop, that causes motor internal circuit breaker to open, stopping the motor.
To stop the sunroof glass other than at the full vent position, release
the sunroof switch when it reaches the desired position. To open the sunshade,
this will have to be manually slid open.
Closing Sunroof from the Vent Position
Closing the sunroof from the vent position, the sunroof switch must
be pulled downward once. This will initiate an express close operation. As
the close mode is initiated, the sunroof switch low reference circuit is
applied to both the sunroof switch open vent signal circuit 12 volt
reference and sunroof switch vent signal circuit 12 volt reference
inputs, pulling them to 0 volts. The sunroof module will control
voltage to the motor outputs to lower the glass to the closed position,
same direction as express opening. The motor will run until the sunroof
limit switch closes, applying the sunroof limit switch low reference circuit
to the sunroof limit switch soft stop signal circuit 12 volt reference
input, pulling the reference voltage to 0 volts, indicating the closed
position has been reached. To close the sunshade, this will have to be manually
slid closed.
Sunroof Motor
The sunroof has a bi-directional motor. When the motor is not operating
both circuits are grounded. When the motor drives the sunroof glass in the
direction from the vent to closed or closed to open position, the following
occurs:
• | Voltage is supplied to the sunroof motor open control circuit. |
• | Ground is maintained to the sunroof motor close control circuit. |
When the motor drives the sunroof glass in the direction from the open
to closed or closed to vent position, the following occurs:
• | Voltage is supplied to the sunroof motor close control circuit. |
• | Ground is maintained to the sunroof motor open control circuit. |
Stuck Switch Protection
If either the sunroof switch open signal circuit or sunroof switch open
vent signal circuit closed for more than 30 seconds, the sunroof
module considers the switch a stuck switch. In this case, the switch input
is ignored by the sunroof module until the switch is opened or the power
is cycled to the module. Under these conditions only, the sunroof is allowed
to close from any position. Once the closed position is obtained, no further
sunroof operation is allowed until the stuck switch is opened or the power
is cycled to the module.