Circuit/System Description
WARNING: This page is about a different car, the 2020 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.
The backup power source provides voltage to the K73 Telematic Control Module to be able to successfully place a call in the event of a main battery disconnect during a collision event. The Communication Interface Module Battery is under an access cover on the K73 Telematic Control Module.