2009 HUMMER H2 overheating

Cooling System
When you decide it is safe to lift the hood, here is what
you will see:
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan{CAUTION:
An electric fan under the hood can start up and
injure you even when the engine is not running.
Keep hands, clothing, and tools away from any
underhood electric fan.
If the coolant inside the coolant surge tank is boiling, do
not do anything else until it cools down. The vehicle
should be parked on a level surface. Check the coolant
level after the system cools down. Some amount of
coolant may be lost due to overheating.
5-27

5. 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. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
7. Verify coolant level after engine is shut off and the
coolant is cold. If necessary, repeat coolant ll
procedure steps 1 through 7.
Engine Coolant
The cooling system in the vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in the vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended life coolant.
The following explains the cooling system and how to add
coolant when it is low. If you have a problem with engine
overheating, seeEngine Overheating on page 5-33.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®can
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at the rst maintenance
service after each 30,000 miles (50 000 km) or
24 months, whichever occurs rst. Any repairs would
not be covered by the vehicle warranty. Always use
DEX-COOL
®(silicate-free) coolant in the vehicle.
5-31

Checking Coolant
The coolant surge tank is
located in the engine
compartment on the
passenger side of the
vehicle. SeeEngine
Compartment Overview on
page 5-14for more
information on location.
{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam and
scalding liquids to blow out and burn you badly.
Never turn the surge tank pressure cap — even a
little — when the engine and radiator are hot.
The vehicle must be on a level surface. When the
engine is cold, the coolant level should be at the FULL
COLD mark.
Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixture at the surge tank, but only when the
engine is cool.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot enough.
Do not spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight and fully seated.
Engine Overheating
You will nd a coolant temperature gage on the vehicle’s
instrument panel. SeeEngine Coolant Temperature
Gage on page 3-39.
In addition, you will nd an ENGINE OVERHEATED
IDLE ENGINE and an ENGINE POWER IS REDUCED
message in the Driver Information Center (DIC) on
the instrument panel. SeeDIC Warnings and Messages
on page 3-56.
5-33

Tires
Your new vehicle comes with high-quality tires
made by a leading tire manufacturer. If you ever
have questions about your tire warranty and where
to obtain service, see your vehicle Warranty
booklet for details. For additional information refer
to the tire manufacturer.
{CAUTION:
Poorly maintained and improperly used tires
are dangerous.
Overloading your vehicle’s tires can
cause overheating as a result of too
much exing. You could have an air-out
and a serious accident. SeeLoading the
Vehicle on page 4-44.
CAUTION: (Continued)
CAUTION: (Continued)

Underinated tires pose the same danger
as overloaded tires. The resulting
accident could cause serious injury.
Check all tires frequently to maintain the
recommended pressure. Tire pressure
should be checked when your vehicle’s
tires are cold. SeeInflation - Tire
Pressure on page 5-63.
Overinated tires are more likely to be
cut, punctured, or broken by a sudden
impact — such as when you hit a
pothole. Keep tires at the recommended
pressure.
Worn, old tires can cause accidents.
If the tire’s tread is badly worn, or if your
vehicle’s tires have been damaged,
replace them.
5-57

Electrical System (cont.)
Power Windows and Other Power Options....5-110
Underhood Fuse Block...............................5-113
Windshield Wiper Fuses.............................5-110
Electronic Immobilizer
PASS-Key
®III+...........................................2-25
Electronic Immobilizer Operation
PASS-Key
®III+...........................................2-26
Electronically Controlled Air Suspension System . . . 4-53
Engine
Air Cleaner/Filter.........................................5-20
Check and Service Engine Soon Lamp...........3-40
Coolant......................................................5-31
Coolant Heater............................................2-31
Coolant Temperature Gage...........................3-39
Drive Belt Routing.......................................6-16
Engine Compartment Overview......................5-14
Exhaust.....................................................2-45
Oil .............................................................5-15
Oil Life System...........................................5-18
Overheated Protection Operating Mode...........5-35
Overheating................................................5-33
Starting......................................................2-29
Entry/Exit Lighting...........................................3-18
Event Data Recorders.....................................7-17
Extender, Safety Belt.......................................1-39
Exterior Lamps...............................................3-15
F
Filter
Engine Air Cleaner......................................5-20
Finish Damage.............................................5-108
First Aid Kit....................................................4-42
Fixed Mast Antenna.......................................3-130
Flashers, Hazard Warning.................................. 3-6
Flash-to-Pass................................................... 3-9
Flat Tire........................................................5-79
Flat Tire, Changing.........................................5-80
Flat Tire, Storing.....................................5-95, 5-98
Fluid
Automatic Transmission................................5-23
Power Steering...........................................5-36
Windshield Washer......................................5-37
Folding Rear Seat...........................................1-11
Four-Wheel Drive............................................5-48
Four-Wheel Drive, Full-Time.............................2-37
Front Axle......................................................5-49
Front Mounted Receiver...................................4-43
Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-6
Driving for Better Economy............................. 4-2
E85 (85% Ethanol)........................................ 5-7
Filling a Portable Fuel Container....................5-10
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