Circuit/System Description
WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. However, it is still accessible from the selected car via links, so may be relevant.
The body control module (BCM) monitors the system voltage to make sure that the voltage stays within the proper range. Damage to components and/or incorrect operation can occur when the voltage is out of range.