GM Service Manual Online
For 1990-2009 cars only

Power Sunroof System Components

The power sunroof system consists of the following components:

    • The sunroof module, includes motor
    • The sunroof switch
    • The sunroof glass
    • The sunshade
    • The rail and track assembly upon which the sunroof glass rides
    • Power supply for the sunroof control module--SUNROOF 20 A fuse.

Power Sunroof Operation

The power sunroof will operate with the ignition switch turned to Accessory or RUN. Once the ignition switch is turned to OFF, from RUN, the sunroof will continue to operate until any door is open or when the retained accessory power (RAP) has timed out. For a complete description of the RAP operation, refer to Retained Accessory Power (RAP) Description and Operation in Computer/Integrating Systems.

Important: After a power loss to the sunroof module through the battery positive voltage circuit protected by the SUNROOF 20 A fuse, the sunroof must be re-initialized. Refer to Sunroof Motor/Actuator Synchronization .

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

    • Express open
    • Closed
    • 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 work from the closed or partially open position. To express open the power sunroof, momentarily press the sunroof switch rearward. This will apply voltage momentarily through the sunroof switch open/tilt down contacts through the sunroof switch open signal circuit to the sunroof module indicating an express open request. From the closed position, the sunroof glass will lower slightly, then automatically slide open the glass between the roof and the headliner, to the full open position. As the sunroof glass express opens, the wind deflector will raise upward and the sunshade will move with the sunroof glass. 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 from the:

    • Open position--Press and hold the sunroof switch forward. This will apply voltage through the sunroof switch close/tilt up contacts through the sunroof switch close signal circuit to the sunroof module. The sunroof switch close/tilt up input at the sunroof module needs to have constant voltage applied, switch pressed, to allow the motor to drive the sunroof glass until it reaches the closed position. 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 closed.
    • Vent position--Press and hold the sunroof switch rearward. This will apply voltage through the sunroof switch open/tilt down contacts through the sunroof switch circuit to the sunroof module. The sunroof switch open/tilt down input to the sunroof module needs to have constant voltage applied, switch pressed, to allow the motor to tilt 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, press and hold the sunroof switch forward. This will apply voltage through the sunroof switch close/tilt up contacts through the sunroof switch close signal circuit to the sunroof module. The sunroof switch close/tilt up input to the sunroof module needs to have constant voltage applied, switch pressed, to allow the motor to tilt the rear of the sunroof glass upward to the vent position.

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 position to the open position, the following occurs:

    • Voltage is supplied to the sunroof motor open control/output 1 circuit.
    • Ground is maintained to the sunroof motor close control/output 2 circuit.

When the motor drives the sunroof in the direction from the open position to the vent position, the following occurs:

    • Voltage is supplied to the sunroof motor close control/output 2 circuit.
    • Ground is maintained to the sunroof motor open control/output 1 circuit.

The sunroof module is equipped with a timer circuit which stops the operation of the sunroof motor after 15 seconds.

The sunroof glass will hard stop each time the sunroof glass reaches the following:

    • Full vent
    • Closed
    • Full open

The hard stop will cause an over current condition that the sunroof module monitors. As an over current condition or hard stop is detected, the sunroof module will stop any motor control outputs.