Circuit/System Description

The sunroof electrical system uses a master/slave configuration utilizing a serial data based system for communication. The body control module (BCM) is designated as the master, while the sunroof motor module is configured as the slave.

As the system master, the BCM uses serial data communication bus to enable or disable sunroof operation, communicate vehicle information to the sunroof motor, and request sunroof movement. The sunroof controller provide system status and diagnostic information to the BCM for diagnostic reporting and operational purposes. The control switches places a different resistor ladder network in the circuit depending on the function selected. The sunroof motor analog to digital switch input reads the resulting voltage range and determines the function.