Circuit/System Description
WARNING: This page is about a different car, the 2018 Buick Envision. However, it is still accessible from the selected car via links, so may be relevant.
The instrument panel multifunction switch contains the ECO switch indicator and ECO switch. If the ECO switch is pressed and other vehicle criteria are met, the Body Control Module (BCM) responds to the request by entering start/stop mode and illuminates the ECO switch indicator. One side of the ECO switch Indicator is provided battery voltage. When ECO mode is achieved, the BCM illuminates the ECO switch indicator by providing ground to the other side of the ECO switch indicator.