Circuit/System Description
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
When the ignition is turned ON, the object alarm module performs a self-test to verify if any critical malfunction exists within the system. When the object alarm system has completed the power-up mode, the object alarm module establishes communication with the body control module (BCM). During the power-up mode the object detection module checks for a valid calibration data set, if no valid calibration set is found, the object alarm module disables the system and commands the red indicator ON.