Theory Of Operation
WARNING: This page is about a different car, the 2014 Dodge Journey. However, it is still accessible from the selected car via links, so may be relevant.
The Intelligent Battery Sensor (IBS) is an electrical shunt with a microprocessor and is located on the negative battery post. The IBS measures current flow, voltage, and temperature. The microprocessor uses this data to calculate state of charge, battery internal resistance, charge received, charge delivered, and time in service. These values are then sent on the LIN bus to the Body Control Module (BCM). The BCM communicates this information to the Powertrain Control Module (PCM) over the CAN bus.