WARNING: This page is about a different car, the 2010 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: High Speed GMLAN
Courtesy of GENERAL MOTORS CORP.
Fig 2: High Speed GMLAN - BUS 2
Courtesy of GENERAL MOTORS CORP.
Fig 3: Low Speed GMLAN
Courtesy of GENERAL MOTORS CORP.
Fig 4: Communications Enable
Courtesy of GENERAL MOTORS CORP.
Fig 5: Local Interconnect Network Bus 1, 3, 4, 9, 11