Sunroof / Moonroof: Description and Operation

SUNROOF DESCRIPTION AND OPERATION

POWER SUNROOF SYSTEM COMPONENTS
The power sunroof system consists of the following components:
- Sunroof module
- Sunroof motor (with the limit switches)
- Sunroof switch
- Sunroof glass (spoiler type, with glass sliding above roof)
- Sunshade
- Rail and track assembly upon which the sunroof glass rides
- Power sunroof system fuse (SUNROOF 20 A fuse)
- Ground (G401)

POWER SUNROOF OPERATION
The power sunroof will operate with the ignition switch turned to ON, supplying power through the ignition 3 voltage circuit to the sunroof module from the SUNROOF fuse. Use the rocker type sunroof switch, located in the front center of the headliner, to command the sunroof to :
- Vent
- Express Open
- Close

Pressing the sunroof switch rearward, the sunroof glass will slide from:
- Closed position to the vent position.
- Vent position to the open position.

Pressing the sunroof switch forward, the sunroof glass will slide from:
- Open position to the vent position.
- Vent position to the closed position.

TO EXPRESS OPEN TO VENT
To open the power sunroof to the vent position from the closed position, momentarily press the sunroof switch rearward. This will apply the sunroof switch low reference to the sunroof switch open signal circuit (5 volt reference) input, pulling the reference voltage to 0 volts. As long as the sunroof module only see a single input request from the sunroof switch (open signal circuit), the module will automatically (express open) open the sunroof glass to the full vent position, raising the rear of the glass upward. The sunroof glass will stop (soft stop) at the full vent position based on the inputs from the limit switches. The sunshade will have to be manually slid open. To stop the sunroof glass in a desired vent position other than the full vent position, toggle the sunroof switch in either direction as the glass is expressing to the full vent position.

EXPRESS OPEN
The express open will work only with the glass in between the full vent and partial open positions. Momentarily press (less than 1.5 seconds) the sunroof switch once, this will apply the sunroof switch low reference to the sunroof switch signal open signal circuit (5 volt reference) input, pulling the reference voltage to 0 volts momentarily. The momentary 0 volts input to the sunroof module indicates an express open request. The sunroof glass will slide automatically (express open) above the roof, allowing the wind deflector to raise upward. The sunroof glass will stop (soft stop) at the full open position based on the inputs from the limit switches. As the sunroof glass expresses open so will the sunshade. To stop the sunroof glass in a desired position other than to the express open position:
- As the sunroof is expressing open, press the sunroof switch again (in either direction) to stop the movement.
- Instead of momentarily pressing the sunroof, maintain pressing (more than 1.5 seconds) the sunroof switch rearward and when the sunroof glass reaches the desired position, then release the switch.

TO CLOSE
To close the power sunroof, press and hold the sunroof switch forward, this will apply the sunroof switch low reference to the sunroof switch close signal circuit (5 volt reference) input, pulling the reference voltage to 0 volts. The sunroof switch close signal input to the sunroof module needs to have constant 0 volts applied (switch pressed) to allow the sunroof motor to continue to drive the sunroof glass past the vent position until it reaches the closed position. The sunroof glass will stop (soft stop) at the closed position based on the inputs from the limit switches. The wind deflector will retract prior to the glass reaching the fully closed position. To close the sunshade, this will have to be manually slid closed.

SUNROOF MOTOR
The sunroof has a bi-directional sunroof motor. When the sunroof motor is not operating both circuits are grounded. When the sunroof motor drives the sunroof glass in the direction from the closed to vent or vent to open position, the following occurs:
- Voltage is supplied to the sunroof motor open circuit.
- Ground is maintained to the sunroof motor close circuit.

When the sunroof motor drives the sunroof glass in the direction from the open to vent or vent to closed position, the following occurs:
- Voltage is supplied to the sunroof motor close circuit.
- Ground is maintained to the sunroof motor open circuit.

The sunroof module is equipped with a timer circuit which stops the operation of the sunroof motor after 8 seconds.

SUNROOF LIMIT SWITCHES
The sunroof limit switches track the position of the glass through two limit switches:
- Soft Stop limit
- Vent Stop limit

The sunroof module monitors the limit switches and based on the inputs determines the position of the sunroof glass. As a limit switch closes, the 5 volt reference will be shorted to the sunroof limit switch low reference circuit, pulling the 5 volt reference to 0 volts.

The sunroof module understands the position of the sunroof glass based on the different input combinations from the sunroof limit switch range switch circuit and the sunroof limit switch soft stop signal circuit inputs.