Circuit/System Description
WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The garage door opener (GDO) is a transmitter operating between 288 and 399 MHz. The GDO has 3 buttons that may be programmed for individual transmitter/receiver combinations to control up to 3 GDOs, security gates, and lighting systems. Each button represents a transmitter code section of the transmitter, which operates separately from any other button, and may be considered a separate transmitter. Battery voltage is provided to the GDO from the PCM fuse in the underhood fuse block.