Sunroof / Moonroof: Description and Operation

Sunroof Description and Operation

Power Sunroof System Components

The Power Sunroof System consists of the following components:

* Sunroof motor/module assembly
* Sunroof switch
* Sunroof glass, tilt/slide style, with glass sliding between the headliner and roof
* Sunshade
* Rail and track assembly upon which the sunroof glass rides
* Power supply for the sunroof motor/module assembly:

- SUNROOF 20-amp fuse for motor operation
- Sunroof module logic circuitry:

* Short wheelbase and Envoy XUV-Retained accessory power (RAP) supply voltage is supplied and controlled directly from the body control module (BCM) for the RAP function.
* Long wheelbase-VENT WDO 20-amp fuse supplies the voltage through the RAP relay, that is controlled by the BCM, for the RAP function.

* Ground from G306

Power Sunroof Operation

The sunroof motor/module assembly has 2 power circuits battery positive voltage and the retained accessory power (RAP) supply voltage circuit. The Sunroof 20-amp fuse is hot at all times suppling the battery positive voltage circuit for the operation of the sunroof motor. The RAP supply voltage circuit is for the sunroof module logic circuitry and is controlled from, or by the body control module (BCM), depending on the wiring configuration. The power sunroof will operate with the ignition switch turned to Accessory or RUN suppling RAP supply voltage. Once the ignition switch is turned to OFF the sunroof will continue to operate until any door is open or when the RAP has timed out.

Use the rocker type sunroof switch to command the sunroof to :

* Express Open
* Close
* Vent

Pressing the sunroof switch rearward, the sunroof glass will slide from:

* Vent position to the closed position
* Closed position to the open position

Pressing the sunroof switch forward, the sunroof glass will slide from:

* Open position to the closed position
* Closed position to the vent position

Express Open

The express open will operate from the closed or partially open position. To express open the power sunroof, turn the ignition to RUN. Press the sunroof switch rearward once. This will apply the sunroof switch low reference to the sunroof switch open signal circuit. From the closed position, the sunroof motor/module assembly will control the motor to lower the rear of the sunroof glass slightly and then slide it rearward between the roof and the headliner, along with the sunshade. The wind deflector will raise upward. To stop the sunroof glass in a desired position other than to the express open position, press the sunroof switch, in either direction, to stop the movement.

To Close

To close the power sunroof, turn the ignition to RUN, and from the:

* Open position-press and hold the sunroof switch forward. This will apply the sunroof switch low reference to the sunroof switch close signal circuit. The sunroof motor/module assembly needs to have a constant switch press to allow the sunroof motor to drive the sunroof glass until it reaches the closed position. 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.
* Vent position-press and hold the sunroof switch rearward. This will apply the sunroof switch low reference to the sunroof switch open signal circuit. The sunroof motor/module assembly needs to have a constant switch press to allow the sunroof motor to drive the rear of the sunroof glass down to the fully closed position.

To Vent Open

To open the power sunroof to the vent position from the closed position, turn the ignition to RUN. Press and hold the sunroof switch forward. This will apply the sunroof switch low reference to the sunroof switch close signal circuit. The sunroof motor/module assembly needs to have a constant switch press to allow the sunroof control module to control the sunroof motor to tilt the rear of the glass upward to the full vent position.

Sunroof Motor

The sunroof motor/module assembly has a bi-directional motor. The sunroof motor understands when it has driven the sunroof glass to the vent, close and full open positions based on the hall effect sensors within the sunroof motor/module assembly. The sunroof motor/module assembly interprets the hall effect sensor combinations and controls the sunroof motor to soft stop the sunroof glass at the positions. After servicing sunroof system components which may effect the position of the glass panel to the seal in the closed position, the soft stop locations must be reset, refer to Sunroof Motor/Actuator Initialization/Teach Process (New Motor) Sunroof Motor/Actuator Initialization/Teach Process (Existing Motor).