How the Circuit Works: GA-Net
WARNING: This page is about a different car, the 2011 Honda Odyssey. However, it is still accessible from the selected car via links, so may be relevant.
The GA-Net bus is basically an audio bus. The GA-Net bus connects the audio-navigation unit, navigation display unit, USB adapter, and XM receiver. Data passed on this bus includes manual audio control functions, such as XM station selection, audio voice commands from the driver, and the muting signal from the audio-navigation unit.