Battery Monitoring System

WARNING: This page is about a different variant/trim than selected.

The BMS control module monitors the condition of the startup battery in all Power Modes.

The BMS control module sends the startup battery State of Charge to the BCM /GWM on a LIN. When the startup battery State of Charge is less than a set threshold from the critical start point, the BMS control module sends a message. The warning message is transmitted to the BCM /GWM .

The BMS control module determines that the control modules are still active when the startup battery State of Charge continuously decreased to less than 50%. When this occurs, the BMS control module sends a shutdown message on the LIN to the BCM /GWM . The BCM /GWM then transmits a shutdown message on the CAN systems buses to all control modules, requesting them to shut down.

When in Power Mode 0 (ignition OFF), the BMS control module monitors the startup battery State of Charge for a further 15 minutes. The BMS control module determines when the startup battery State of Charge is still dropping due to the quiescent drain current. The BMS control module sends a power disconnect signal to the BCM /GWM on the LIN. The BCM /GWM then sends a signal to the PJB on the hardwired connections to open its internal relays. When the PJB relays are open, the power supply from the startup battery to non-critical control modules is removed. The non-critical control modules are any modules associated with the infotainment system and also the climate control system.

The use of the LIN communication makes sure that no other control modules 'wake' during this process. When CAN systems bus communication was used, all modules on the CAN systems bus would be woken by the message.