Sunroof / Moonroof: Description and Operation

SUNROOF DESCRIPTION AND OPERATION

POWER SUNROOF SYSTEM COMPONENTS
- Sunroof control module
- Sunroof motor, with limit switch
- Sunroof switch
- Sunroof glass
- Rail and track assembly upon which the sunroof glass rides
- LIFTGATE/SUNROOF Fuse 20-A
- Ground G401

The sunroof module contains the logic for the opening and the closing of the sunroof. The sunroof motor assembly contains the reversible DC drive motor, the gear train, and the soft stop limit switch.

The sunroof module determines the sunroof motor direction based on inputs received from the overhead console sunroof switches. When the ignition switch is in the ON position or when retained accessory power (RAP) is active, voltage is applied to the sunroof module. The sunroof module controls the sunroof motor direction by changing the polarity of the applied voltage. The sunroof module remembers the sunroof position whenever the ignition switch is turned to the OFF position. The limit switch is used as an input to the sunroof module to indicate that the glass is fully closed, or in the comfort stop positions. The limit switch is grounded when the sunroof glass is in the fully closed or comfort stop positions, otherwise it is open.

Express Open
The EXPRESS OPEN mode is initiated by momentarily moving the sunroof slide switch rearward to the second position (EXPRESS OPEN). This applies a ground through both the sunroof switch open signal and the sunroof switch express signal circuits to the sunroof module. The sunroof module will then control voltage to the control circuits of the sunroof motor. The sunroof motor will run until the limit switch contacts are closed, indicating the comfort stop position has been reached. The comfort stop position is a predetermined position that the sunroof glass will open to allowing minimal wind noise. If the sunroof slide switch is pressed again, the sunroof motor will run until a mechanical stop is met in the sunroof track, indicating the fully open position. Also, the sunroof module will revert back to manual operation if the switch is not released within 1 second. As the sunroof is expressing open the wind deflector will raise upward and the sunshade will slide along with the glass.

Slide Close
The SLIDE CLOSE mode is initiated by moving and holding the sunroof slide switch forward. This applies a ground to the sunroof switch close vent signal input of the sunroof module. The sunroof module controls voltage to the control circuits of the sunroof motor. The sunroof motor will run until the limit switch contacts are closed, indicating the flush closed position has been reached. As the sunroof is approaching the close position the sunroof glass will force the wind deflector downward. The sunshade must be manually closed.

Slide Open
The SLIDE OPEN mode is initiated by moving and holding the sunroof slide switch rearward to the first position. This applies a ground through the sunroof switch open signal circuit to the sunroof module. The sunroof module controls voltage to the control circuits of the sunroof motor. The sunroof motor will run until the a mechanical stop is met in the sunroof track, indicating the fully open position. As the sunroof is opening the wind deflector will raise upward and the sunshade will slide along with the glass.

Vent Open
The VENT OPEN mode is initiated by pressing and holding the rear portion of the sunroof vent switch. This applies a ground through the sunroof switch open vent signal circuit to the sunroof module. The sunroof module controls voltage to the control circuits of the sunroof motor. The sunroof motor will run until a mechanical stop is met in the sunroof track, indicating the vent open position. The sunshade must be manually opened.

Vent Close
The VENT CLOSE mode is initiated by pressing and holding the forward portion of the sunroof vent switch. This applies a ground through the sunroof switch close vent signal circuit to the sunroof module. The sunroof module controls voltage to the control circuits of the sunroof motor. The sunroof motor will run until the limit switch contacts are closed, indicating the flush closed position has been reached. The sunshade must be manually closed.

Stuck Switch
The sunroof system has a sunroof stuck switch feature that will allow a closing due to one of the sunroof switch signal circuits being shorted to ground or a faulty sunroof switch. If either the sunroof switch open, open vent or express signal circuits should become grounded, that sunroof signal circuit will input a low signal to the sunroof module. This will drive the sunroof window to the requested position. If the same signal circuit continues to remain low, as if a stuck sunroof switch or a short to ground, the sunroof module will ignore any other input request for 1 minute. After 1 minute, a request to close the sunroof window will be granted once the sunroof switch is pressed to the close position. The sunroof system will become inoperative once in the close position, until the ignition is cycled back on.