Battery Current Sensor
WARNING: This page is about a different car, the 2018 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.
Vehicles without the Auto-start-stop system are equipped with a battery current sensor. The battery current sensor is attached to the battery negative cable. It is supplied a 5-volt reference voltage and a ground from the BCM. The battery current sensor is a Hall-effect sensor that supplies an analog feedback signal to the BCM. The BCM reads the battery current sensor feedback voltage to determine how much current is flowing through the battery ground cable. The BCM uses this information for battery state of charge.