Battery Gauge
WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
The instrument panel cluster (IPC) displays the voltage as determined by the regulated voltage control (RVC). The IPC receives a serial data message from the BCM indicating the battery voltage. When the engine is ON, the gauge should be between 10 - 16 volts. The gauge will default to 0 volts if the IPC detects a loss of communication with the BCM.