Sunroof Relay (If Equipped)
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 Chevrolet Tahoe, 2003 Chevrolet Suburban, and 2003 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The BCM has a discrete output used for the control of the sunroof relay. In the RAP power mode the BCM will supply a B+ to the control circuit to enable the relay. The BCM also enables the relay in the Accessory and Run power modes. Refer to RETAINED ACCESSORY POWER (RAP) SCHEMATICS to become familiar with the system and for the circuit identification.