GM Service Manual Online
For 1990-2009 cars only

    Important: The sunroof motor has an internal microswitch which opens the motor circuit, turns motor OFF, when the glass reaches the full vent position. If the motor is operated separately from the sunroof module, or the position of the sunroof is changed without the motor installed, the timing of the sunroof motor to the sunroof module will be out of phase. Putting the motor back into the module while it is out of phase will result in the loss of the vent positioning feature. If the motor and the module become out of phase, or the vent positioning feature is not functioning, use the following procedure to re-time the motor:

  1. Use the sunroof switch to operate the actuator until the glass is in full vent position.
  2. Disconnect the actuator connectors.
  3. Remove the sunroof actuator. Refer to Sunroof Actuator Replacement .
  4. Re-install the connectors.
  5. Important: The vent position is the first detent of the sunroof switch. If the switch is pushed to the second detent, which is the OPEN position, the actuator will not be timed.

  6. Push the sunroof switch to VENT position and hold until the actuator stops. The actuator in now timed to the VENT position.
  7. Install the actuator. Refer to Sunroof Actuator Replacement