The vehicle has a battery saver feature designed to protect the vehicle's battery.
When any interior lamp is left on and the ignition is turned off, the battery rundown protection system automatically turns the lamp off after 20 minutes.
This prevents draining of the battery.
Electric Power Management
Accessory Power Outlet(s)Chevrolet Cobalt Owners Manual. Passenger Airbag Status Indicator
If the vehicle has one of the passenger airbag status
indicators pictured in the following illustrations, then the
vehicle has a passenger sensing system for the right
front passenger position. The passenger airbag status
indicator, if equipped, is on the instrument panel. See
Passenger Sensing ...