REAR ACCESS OPEN Message
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The instrument panel cluster (IPC) illuminates the REAR ACCESS OPEN message when the body control module (BCM) detects that the liftgate or liftglass is ajar or open. The IPC receives a LAN message from the BCM requesting illumination. If the vehicle is in the forward or reverse gear position, the BCM activates an audible warning.