Electrical Load Management
The electrical load management is controlled by the GWM and the BMS control module.
The GWM will monitor the vehicle system power loads before and during an ECO engine stop.
Before an ECO engine stop, the GWM will transmit a signal to system control modules on the CAN bus to request a power save on all electrical loads and set a minimum electrical value override. The GWM monitors the vehicle electrical loads and will inhibit a ECO engine stop until the load current is at a value low enough to be supported by the secondary battery.
If the electrical loads cannot be reduced sufficiently, the GWM will inhibit the ECO engine stop.
When the engine is stopped after an ECO engine stop, the GWM will continue to monitor the primary battery state of charge. If the primary or secondary battery voltage falls below 11.0V, a level which will result in degraded starting performance or possible primary battery damage, the GWM will initiate an engine start.
System Inhibits
The ECO stop/start system is inhibited if the dual battery system is not be capable of preventing electrical loads on the vehicle being subject to unacceptably low voltage levels during ECO stop/start operations due to a fault.
ECO stop/start inhibit monitoring of the primary battery is performed by the BMS control module. If the primary battery voltage is too low to support an ECO stop/start, then the BMS control module will send a message to the GWM on the LIN bus to suspend ECO stop/start.
The GWM monitors the secondary battery and the dual battery system components. Any fault found will cause the GWM to inhibit ECO stop/start and the GWM will record a DTC (diagnostic trouble code).