It is not necessary to check the transmission fluid level.
A transmission fluid leak is the only reason for fluid loss. If a leak occurs, take your vehicle to a dealer/ retailer and have it repaired as soon as possible.
Change the fluid and filter at the intervals listed in the
Maintenance Schedule. See Scheduled Maintenance. Be sure to use the transmission
fluid
listed in Recommended Fluids and Lubricants.
Notice: Use of the incorrect automatic transmission fluid may damage the vehicle, and the damages may not be covered by the vehicle's warranty. Always use the automatic transmission fluid listed in Recommended Fluids and Lubricants.
Chevrolet Cobalt Owners Manual. Engine Coolant Temperature Warning Light
This light comes on briefly
while starting the vehicle.
If it does not, have the vehicle serviced by the
dealer/retailer. If the system is working normally
the indicator light goes off.
Notice: Driving with the engine coolant temperature
warning light on could cause the vehicle to
overheat. ...