1995 GMC Yukon Owner's Manual - Page 249

If the warning continues, pull over, stop, and park your vehicle right away. If there's still no sign of steam, push the accelerator until the engine speed is about twice as fast as normal idle speed. Bring the engine speed back to normal idle speed after two or three minutes. Now see if the warning stops. But then, if you still have the warning, turn o f t h e engine and get everyone out of the vehicle until it cools down. You may decide not to lift the hood but to get service help right away. Cooling System- Gasoline Engines When you decide it's safe to lift the hood, here's what you'll see: A. Coolant recovery tank B. Engine fan(s) C. Radiator pressure cap If the coolant inside the coolant recovery tank is boiling, don't do anything else until it cools down. 5-1 1