WARNING: This page is about a different car, the 2010 Buick LaCrosse. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: High Speed GM LAN (F46)
Courtesy of GENERAL MOTORS CORP.
Fig 2: High Speed GM LAN (without F46)
Courtesy of GENERAL MOTORS CORP.
Fig 3: High Speed GM LAN Bus 2
Courtesy of GENERAL MOTORS CORP.
Fig 4: Low Speed GM LAN
Courtesy of GENERAL MOTORS CORP.
Fig 5: Communications Enable
Courtesy of GENERAL MOTORS CORP.
Fig 6: Local Interconnect Network Bus 1, 2, 3, 4
Courtesy of GENERAL MOTORS CORP.
Fig 7: Local Interconnect Network Bus 6, 8, 9, 10, 11, and CAN Graphical Interface