GMC 2009 Sierra - Manual (Page 338)

Coolant Surge Tank Pressure Cap
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.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. See Engine
Compartment Overview on page 5-12 for more
information on location.
Engine Overheating
There is a coolant temperature gage on your vehicle’s
instrument panel. See Engine Coolant Temperature
Gage on page 3-43.
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 3-59.
If Steam Is Coming From Your Engine
{ CAUTION:
Steam from an overheated engine can burn
you badly, even if you just open the hood.
Stay away from the engine if you see or hear
steam coming from it. Turn it off and get
everyone away from the vehicle until it cools
down. Wait until there is no sign of steam or
coolant before you open the hood.
If you keep driving when the vehicles engine
is overheated, the liquids in it can catch fire.
You or others could be badly burned. Stop
your engine if it overheats, and get out of
the vehicle until the engine is cool.
See Overheated Engine Protection Operating
Mode on page 5-28 for information on driving
to a safe place in an emergency.
5-26