Fuel Economy Mode
WARNING: This page is about a different car, the 2007 Suzuki XL7. However, it is still accessible from the selected car via links, so may be relevant.
The BCM will enter Fuel Economy Mode when the estimated battery temperature is at least 0°C (32°F) but less than or equal to 80°C (176°F), the calculated battery current is less than 15 ampers and greater than - 8 ampers, and the battery SOC is greater than or equal to 80%. It's targeted generator output voltage is the open circuit voltage of the battery and can be between 12.5 and 13. 1 volts. The BCM will exit this mode and enter Charge Mode when any of the conditions described above are present.