LIFTGATE OPEN Indicator
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
Manual Liftgate
The instrument panel cluster (IPC) illuminates the LIFTGATE OPEN indicator when the body control module (BCM) detects that the liftgate is open. The IPC receives a serial data message from the BCM requesting illumination. If the vehicle is in the forward or reverse gear position, the BCM activates an audible warning.
Power Liftgate
The liftgate module (LGM) detects the liftgate ratchet switch is closed to ground indicating the liftgate is open. The IPC receives a serial data message from the LGM indicating the liftgate ajar status and the driver information center (DIC) illuminates the LIFTGATE OPEN indicator.