Trunk Ajar-28
WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
The DIC displays the TRUNK AJAR-28 indicator when the rear integration module (RIM) detects that the trunk is open or ajar. The DIC receives a class 2 message form the RIM requesting illumination. The IPC sends a class 2 message to the radio in order to activate an audible warning.