Sunroof Description and Operation: Notes

The sunroof system consists of a moving glass panel and a 2nd fixed glass panel located just behind the moving glass panel. The moving glass component slides over the top of the fixed glass, and the roof panel. There is also a power roller sunshade which covers both glass panels. The electrical portion of the system controls the opening and closing of the sunroof glass and the power roller sunshade. The ignition must be in ON/RUN/START, ACC/ACCESSORY, or in retained accessory power (RAP) to operate the sunroof/sunshade.

The electrical portion of the spoiler sunroof system consists of:

• Body control module (BCM)
• Sunroof control module
• Sunshade control module
• Sunroof control switch assembly
• Sunshade control switch assembly

The BCM communicates with the sunroof glass and sunshade control module to enable or disable sunroof and sunshade operation. The sunroof/sunshade control modules provide system status and diagnostic information to the BCM for diagnostic reporting and operational purposes.

The sunroof glass and power sunshade are each controlled by its own integrated motor/controller containing the necessary electronics, motor, hall effect position sensors, as well as the interface to the driver control switches. Each motor/controller is capable of controlling motion based on control switch activation and message commands from the BCM.

There are times when the sunshade and sunroof operation are dependent on each other (see below). This dependency is controlled by the BCM.

Fig 1: Sunroof System Block Diagram

Courtesy of GENERAL MOTORS COMPANY