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For 1990-2009 cars only

Sunroof Description and Operation Before VIN 209983

The power sunroof (CF5 option) has the following features:

    • A manually operated sunshade. A recess is provided in the sunshade to be used to push the shade open or pull it shut.
    • An express module at the front of the sunroof module, allows the window panel to stop in the closed, vent and fully open positions.
    • The position encoding system (PES) module contains the limit switches for the window panel operation. Its gearing drives the window into the desired position. The window panel must be in the closed position when this unit is replaced.
    • The sunroof actuator attaches to the PES module and contains the driveshaft that drives the gearing in the PES. This driveshaft will turn infinitely in both directions.
    • The power sunroof switch is a 2 position rocker type switch which electrically operates the power sunroof. The switch is located in the headliner in front of the sunroof. Press and hold the front indent position to move the sunroof glass to the vent position. Press and hold rear indent and the sunroof will return to the full closed position.
        Press rear indent once and the sunroof glass will slide to the full open position automatically (express open).
        Press and hold the front indent position on the control switch in order to close the sunroof window from the open position. The switch must be held until the window reaches a desired position or until it closes completely.
    • A drain trough is positioned under the sunroof glass panel. Water is collected by this trough and is drained off by drain hoses connected at each corner.
    • The glass panel seal fits around the glass panel and is used to seal the opening between the glass panel and the roof panel.
    • The sunroof electrical harness is routed to join the body harness at the right rear pillar.

Power Sunroof System Components

The power sunroof system consists of the following components:

    • Actuator/motor
    • Sunroof control module
    • Sunroof limit switches (position encoding system [PES] module)
    • Sunroof switch
    • Sunroof glass (tilt/slide type, with glass sliding between roof and headliner)
    • Sunshade
    • Rail and track assembly upon which the sunroof glass rides
    • Power supply for the sunroof module: PWR WINDOWS PWR SUN ROOF 30 A circuit breaker
    • Ground from G402

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 the sunroof will continue to operate until any door is open or when the retained accessory power (RAP) has timed out. For a description and operation of the RAP system, refer to Retained Accessory Power (RAP) Description and Operation in Retained Accessory Power.

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 portion), the sunroof glass will slide from:

    • Vent position to the closed position
    • Closed position to the open position

Pressing the sunroof switch (forward portion), the sunroof glass will slide from:

    • Open position to the closed position
    • Closed position to the vent position

To Vent Open

To open the power sunroof to the vent position from the closed position, turn the ignition to ON, with engine OFF. Press and hold the sunroof switch (forward portion). This will apply the sunroof switch low reference to the sunroof switch close signal circuit (5 volt reference) input to drop to 0 volts. As long as the sunroof module sees a constant input request from the sunroof switch close signal circuit (0 volts), the module will continue to raise the rear of the glass upward to the full vent position. The sunroof glass will stop (soft stop) at the full vent position based on the inputs from the limit switches. To stop the sunroof glass in a position other than the full vent position, release the sunroof switch when the sunroof glass reaches the desired vent position. The sunshade will have to manual slid open.

To Close from Vent Position

To close the power sunroof from the vent position, turn the ignition ON, with the engine OFF. Press and hold the sunroof switch (rearward portion). This will apply the sunroof switch low reference to the sunroof switch open signal circuit (5 volt reference) input to drop to 0 volts. As long as the sunroof module sees a constant input request from the sunroof switch open signal circuit (0 volts), the module will continue to lower the rear of the glass (downward) to the closed position. The sunroof glass will stop (soft stop) at the closed position based on the inputs from the limit switches. The sunshade will have to be manually slid closed.

Express Open

The express open will work only with the glass in between the closed and partially open positions. To express open the power sunroof, turn the ignition ON, with engine OFF. Press the sunroof switch (rearward portion) once (less than 1.5 seconds). This will apply the sunroof switch low reference to the sunroof switch signal open signal circuit (5 volt reference) input to drop to 0 volts momentarily. The momentary 0 volts input to the sunroof control module indicates an express open request. The sunroof glass will lower slightly, then begin to automatically slide (express open) between the roof and headliner, 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 switch to express open, maintain pressing (more than 1.5 seconds) the sunroof switch (rearward portion). When the sunroof glass reaches the desired position, then release the switch.

To Close from Open Position

To close the power sunroof from the open position is the same as to opening the sunroof glass to the vent position. Turn the ignition ON, with the engine OFF. Press and hold the sunroof switch (forward portion). This will apply the sunroof switch low reference to the sunroof switch close signal circuit (5 volt reference) input to drop to 0 volts. As long as the sunroof module sees a constant input request from the sunroof switch close signal circuit (0 volts), the module will continue to slide the sunroof glass to the closed position. The sunroof glass will stop (soft stop) at the closed position based on the inputs from the limit switches. The sunshade will have to be manually slide 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 feed open circuit.
    • Ground is maintained to the sunroof motor feed close circuit.

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

    • Voltage is supplied to the sunroof motor feed close circuit.
    • Ground is maintained to the sunroof motor feed open circuit.

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

Limit Switches

The limit switches are part of the position encoding system (PES) that tracks the position of the glass through the limit switches and understands the limits (soft stops) of travel to the:

    • Full vent position
    • Full open position

The sunroof control module monitors the limit switches (PES). As a limit switch closes, the sunroof limit switch circuit 5 volt reference will be shorted to the sunroof limit switch low reference circuit, pulling the reference voltage to 0 volts. The sunroof control module understands the position of the sunroof glass based on the multiple input combinations through the limit switch inputs, which brings the sunroof glass to a soft stop when it reaches the full vent or full open positions and when it has reached the closed position.

Sunroof Maintenance

  1. Clean the surface of the window by wiping with a clean, dampened cloth using GM Window Cleaner GM P/N 10500427 or equivalent.
  2. Apply a silicone lubricant GM P/N 12345579 or equivalent (Canadian P/N 1974984) in order to perform the following functions:
  3. • Prolong the weatherstrip life
    • Help to seal the weatherstrip
    • Assist in eliminating squeaks

Sunroof Description and Operation After VIN 209983

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 A 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 A 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 A 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. For a description and operation of the RAP operation, refer to Retained Accessory Power (RAP) Description and Operation in Retained Accessory Power.

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 internal 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.