2004 HUMMER H2 heating

Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don’t shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
You can tow in DRIVE (D). You may want to shift the
transmission to THIRD (3) or, if necessary, a lower gear
selection if the transmission shifts too often (e.g.,
under heavy loads and/or hilly conditions).
You may also want to activate the tow/haul mode if the
transmission shifts too often. See “Tow/Haul Mode”
earlier.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) for a
few minutes before turning the engine off. If you do get
the overheat warning, seeEngine Overheating on
page 5-27.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if you ever have to park your rig on a hill, here’s
how to do it:
1. Apply your regular brakes, but don’t shift into
PARK (P) yet.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake and shift into PARK (P).
5. Release the regular brakes.
4-83

Service............................................................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of Your
Vehicle......................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-14
Engine Air Cleaner/Filter................................5-19
Automatic Transmission Fluid.........................5-21
Engine Coolant.............................................5-24
Coolant Surge Tank Pressure Cap..................5-27
Engine Overheating.......................................5-27
Cooling System............................................5-30Engine Fan Noise.........................................5-35
Power Steering Fluid.....................................5-36
Windshield Washer Fluid................................5-37
Brakes........................................................5-38
Battery........................................................5-42
Jump Starting...............................................5-43
All-Wheel Drive..............................................5-48
Rear Axle.......................................................5-50
Front Axle......................................................5-51
Bulb Replacement..........................................5-52
Halogen Bulbs..............................................5-52
Headlamps..................................................5-52
Front Turn Signal and Parking Lamps..............5-53
Sidemarker Lamps........................................5-54
Daytime Running Lamps................................5-54
Roof Marker Lamps......................................5-55
Center High-Mounted Stoplamp (CHMSL).........5-57
Taillamps.....................................................5-57
Replacement Bulbs.......................................5-58
Windshield Wiper Blade Replacement..............5-59
Section 5 Service and Appearance Care
5-1

Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs rst, if you add
only DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating on
page 5-27.
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
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOL®coolant which won’t damage
aluminum parts. If you use this coolant mixture,
you don’t need to add anything else.
5-24

Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixtureat 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.
Coolant Surge Tank Pressure Cap
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. SeeEngine
Compartment Overview on page 5-12for more
information on location.
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
You will nd a coolant temperature gage on your
vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 3-35. In addition, you will
nd an ENGINE COOLANT HOT, ENGINE
OVERHEATED and a REDUCED ENGINE POWER
message in the DIC on the instrument panel. SeeDIC
Warnings and Messages on page 3-56.
5-27

{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. Just 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 your engine is
overheated, the liquids in it can catch re. 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” underEngine Overheating on page 5-27
for information on driving to a safe place in an
emergency.Notice:If your engine catches re because you
keep driving with no coolant, your vehicle can
be badly damaged. The costly repairs would not be
covered by your warranty. See “Overheated
Engine Protection Operating Mode” underEngine
Overheating on page 5-27for information on driving
to a safe place in an emergency.
If No Steam Is Coming From Your
Engine
An overheat warning, along with a low coolant condition,
can indicate a serious problem.
If you get an engine overheat, but see or hear no
steam, the problem may not be too serious. Sometimes
the engine can get a little too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer. SeeTowing a Trailer on page 4-75.
5-29

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 GM Warranty booklet for details. For additional
information refer to the tire manufacturer’s booklet
included with your vehicle’s Owner’s Manual.
{CAUTION:
Poorly maintained and improperly used tires
are dangerous.
Overloading your tires can cause
overheating as a result of too much
friction. You could have an air-out and a
serious accident. See “Loading Your
Vehicle” in the Index.
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 tires are cold.
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
your tread is badly worn, or if your tires
have been damaged, replace them.
Tire Sidewall Labeling
Useful information about a tire is molded into the
sidewall. The following illustrations are examples of a
typical P-Metric and a LT-Metric tire sidewall.
5-60

Driver
Position, Safety Belt.....................................1-22
DRIVER DOOR AJAR.....................................3-60
Driver Information Center (DIC).........................3-44
DIC Operation and Displays..........................3-44
DIC Warnings and Messages........................3-56
Driving
At Night.....................................................4-41
City...........................................................4-46
Defensive..................................................... 4-2
Drunken....................................................... 4-3
Freeway.....................................................4-47
Hill and Mountain Roads..............................4-50
In Rain and on Wet Roads...........................4-43
Off-Road....................................................4-17
Winter........................................................4-52
Driving Across an Incline..................................4-36
Driving Downhill..............................................4-35
Driving in Mud, Sand, Snow or Ice....................4-39
Driving in Water..............................................4-40
Driving On Grades..........................................4-83
Driving on Off-Road Hills.................................4-31
Driving on Snow or Ice....................................4-52
Driving Through Deep Standing Water...............4-45
Driving Through Flowing Water.........................4-45
Driving Uphill..................................................4-32
Driving with a Trailer.......................................4-81E
Easy Exit Seat...............................................2-53
Electrical System
Add-On Equipment.....................................5-101
Fuses and Circuit Breakers.........................5-102
Power Windows and Other Power Options....5-102
Windshield Wiper Fuses.............................5-102
Electronically Controlled Air Suspension System....4-74
Emissions Inspection and Maintenance
Programs...................................................3-40
Engine
Air Cleaner/Filter.........................................5-19
Battery.......................................................5-42
Check and Service Engine Soon Light............3-38
Coolant......................................................5-24
Coolant Heater............................................2-21
Coolant Temperature Gage...........................3-35
Drive Belt Routing.......................................6-15
Engine Compartment Overview......................5-12
Exhaust.....................................................2-33
Fan Noise..................................................5-35
Oil .............................................................5-14
Overheating................................................5-27
Starting......................................................2-20
ENGINE COOLANT HOT.................................3-57
Engine Oil Additives........................................5-17
5

Garage Door Opener.......................................2-42
Gasoline
Octane........................................................ 5-5
Specications............................................... 5-5
Gate Operator and Canadian Programming........2-44
Getting Familiar with Off-Road Driving................4-28
Glove Box.....................................................2-45
GM Mobility Program for Persons with
Disabilities.................................................... 7-5
H
Hazard Warning Flashers................................... 3-4
Head Restraints............................................... 1-6
Headlamp High/Low-Beam Changer.................... 3-7
Headlamps....................................................5-52
Bulb Replacement.......................................5-52
Daytime Running Lamps...............................5-54
Front Turn Signal and Parking Lamps.............5-53
Halogen Bulbs............................................5-52
Roof Marker Lamps.....................................5-55
Sidemarker Lamps.......................................5-54
Heated Seats................................................... 1-4
Heating.........................................................3-24
High Mobility Characteristics.............................4-24
Highway Hypnosis...........................................4-49
Hill and Mountain Roads..................................4-50
Hitches..........................................................4-80HomeLink
®Transmitter....................................2-42
HomeLink®Transmitter, Programming................2-42
Hood
Checking Things Under................................5-10
Release.....................................................5-10
Horn............................................................... 3-5
How to Add Coolant to the Coolant Surge Tank......5-32
How to Add Fluid............................................5-23
How to Check Lubricant...................................5-50
How to Check Power Steering Fluid..................5-36
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-21
Hydroplaning..................................................4-45
I
If No Steam Is Coming From Your Engine..........5-29
If Steam Is Coming From Your Engine...............5-28
If the Light is Flashing.....................................3-39
If the Light Is On Steady.................................3-39
If You Are Caught in a Blizzard.........................4-54
If You Are Stuck in Sand, Mud, Ice or Snow.......4-56
If You Do Decide To Pull A Trailer.....................4-76
Ignition Positions.............................................2-19
Illuminated Visor Vanity Mirrors.........................2-16
Infants and Young Children, Restraints...............1-40
Ination - Tire Pressure...................................5-68
7