The vehicle must be on a level surface when checking the coolant level.
It is normal to see coolant moving in the upper coolant hose return line when the engine is running.
Check to see if coolant is visible in the coolant surge tank. If the coolant inside the coolant surge tank is boiling, do not do anything else until it cools down.

If coolant is visible but the coolant level is not at or above the mark pointed to, add a 50/50 mixture of clean drinkable water and DEX-COOL coolant.
Be sure the cooling system is cool before this is done.
What to Use
How to Add Coolant to the Coolant Surge TankVehicle Data
Capacities and Specifications
The following approximate capacities are given in metric and English conversions.
See Recommended Fluids and Lubricants on page 11-12 for more information.
Engine Drive Belt Routing
...
Where to Put the Restraint
According to accident statistics, children and infants are safer when properly
restrained in a child restraint system or infant restraint system secured in a rear
seating position.
Whenever possible, children aged 12 and under should be secured in a rear seating
position.
Never put a rear-fa ...
Insuring the Vehicle
Protect your investment in the GM vehicle with comprehensive and collision insurance
coverage. There are significant differences in the quality of coverage afforded
by various insurance policy terms.
Many insurance policies provide reduced protection to the GM vehicle by limiting
compensation ...