Circuit/System Description
WARNING: This page is about a different car, the 2012 Buick Verano. However, it is still accessible from the selected car via links, so may be relevant.
The instrument panel cluster (IPC) illuminates the cruise control engaged indicator based on serial data messages received from the engine control module (BCM) or the powertrain control module (ECM). The indicator is commanded ON when the cruise control switch is turned ON and turned OFF with the system disengaged.