Engine Overheating - GMC 2010 Yukon XL Denali Owner's Manual

4. With the coolant surge tank pressure cap off, start
the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fan.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge
tank until the level reaches the FULL COLD mark.
6-32
5. Replace the pressure cap. Be sure the pressure
cap is hand-tight and fully seated.
6. Verify coolant level after engine is shut off and the
coolant is cold. If necessary, repeat coolant fill
procedure Steps 1 through 6.
Notice: If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.

Engine Overheating

The vehicle has several indicators to warn of engine
overheating.
There is a coolant temperature gage on your vehicle's
instrument panel. See Engine Coolant Temperature
Gage on page 4 34.
In addition, ENGINE OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE ENGINE, and a ENGINE
POWER IS REDUCED message comes on in the Driver
Information Center (DIC) on the instrument panel.
See DIC Warnings and Messages on page 4 56.
You may decide not to lift the hood when this warning
appears, but instead get service help right away.
See Roadside Assistance Program on page 8 7.