2006 GMC Canyon Owner's Manual - Page 306

Cooling System When you decide it is safe to lift the hood, here is what you will see: A. Coolant Recovery Tank B. Engine Cooling Fan C. Radiator Pressure Cap If the coolant inside the coolant recovery tank is boiling, do not do anything else until it cools down. The vehicle should be parked on a level surface. When the engine is cold, the coolant level should be at least up to the FULL COLD mark. If it is not, you may have a leak at the pressure cap or in the radiator hoses, heater hoses, radiator, water pump or somewhere else in the cooling system. 5-30