Sunroof / Moonroof: Description and Operation

Sunroof Description and Operation

Power Sunroof System Components

The Power Sunroof System consists of the following components:

* Sunroof control module
* Sunroof switch
* Sunroof glass
* Rail and track assembly upon which the sunroof glass rides
* Sunroof sunshade
* S/ROOF 15A Fuse
* Ground G302

Power and Grounds

Battery positive voltage is supplied at all times to the sunroof control module from the 15 A S/ROOF fuse located in the rear fuse block. Ground is supplied to the sunroof control module through the module ground circuit and G302.

Ground is supplied to the sunroof switch through the switch ground circuit and G302.

Power Sunroof Operation

The Power Sunroof System will operate only with the ignition turned to the RUN or Accessory position, this allows for retained accessory power (RAP) control of the sunroof through the body control module (BCM). With the ignition in the run or accessory position, the BCM supplies the sunroof with ignition voltage which allows sunroof operation. Once the ignition switch is turned off the sunroof will continue to operate until any door is opened or when the RAP timer reaches its shut-off limit. For a description and operation of the RAP operation, refer to Retained Accessory Power Description and Operation (Retained Accessory Power).

Note:
* If, during service, the sunroof control module has lost battery positive voltage or ground, or has been replaced, it will be necessary to initialize the control module once service has been completed. Refer to Control Module References (Programming and Relearning).
* The sunroof can be manually cycled with a regular screwdriver, once the headliner is removed. This screwdriver fits into the drive gear, and when turned will operate the sunroof drive cables and simultaneously open or close the sunroof.

When the sunroof is commanded to open, it will move the sunshade to the open position as well. The sunshade can be manually opened and closed from inside of the vehicle while the sunroof is in the closed position. The sunshade is designed to stay in the open position while the sunroof is in the open position.

Any water that passes the roof seal is drained from the sunroof tray by 4 tubes that lead from the corners of the tray to the rocker panels of the vehicle. The tray which acts as a framework for the sunroof assembly, has a water channel that encircles the sunroof opening and directs the water to the drain tubes.

Sunroof Switch Operation

When the sunroof is in the closed position, it can be raised to the vent position by pressing the OPEN/VENT side of the switch lever once. The sunroof may then be expressed to the fully open position by momentarily pressing the OPEN/VENT side of the switch lever a second time, or it may be adjusted to any preferred open position by pressing and holding the OPEN/VENT side of the switch lever until the sunroof has reached the desired position. To fully close the sunroof, press and hold the CLOSE side of the switch lever. Release the CLOSE side of the switch lever in order to stop the sunroof at any preferred closed position. Whenever the sunroof is in the express open mode, it can be stopped by momentarily pressing either side of the switch.

Sunroof Control Module

The sunroof control module is located between the headliner and the roof structure, while the sunroof switch is located above the rearview mirror. The sunroof control module supplies voltage to the contacts of the sunroof switch through the sunroof switch close signal circuit and the sunroof switch open signal circuit. The sunroof control module also supplies ground to the switch contacts through the sunroof switch low reference circuit. When the switch is operated, the contacts and signal circuit for the selected mode are closed to ground, the voltage is pulled low in the sunroof control module, and the appropriate signal is recognized by the sunroof control module. The sunroof control module then internally applies battery positive voltage and ground to the appropriate circuits of the reversible power sunroof motor in order to move the sunroof glass to the open, close, or vent position.