2008 HUMMER H2 heater

The coolant level should be at or above the FULL
COLD mark. If it is not, you may have a leak at the
pressure cap or in the radiator hoses, heater hoses,
radiator, water pump, or somewhere else in the cooling
system.
{CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Do not touch them.
If you do, you can be burned.
Do not run the engine if there is a leak. If you
run the engine, it could lose all coolant. That
could cause an engine re, and you could be
burned. Get any leak xed before you drive the
vehicle.If there seems to be no leak, start the engine again.
The engine cooling fan speed should increase when idle
speed is doubled by pushing the accelerator pedal
down. If it does not, your vehicle needs service.
Turn off the engine.
Notice:Engine damage from running your engine
without coolant is not covered by your warranty.
SeeOverheated Engine Protection Operating Mode
on page 5-28for information on driving to a safe
place in an emergency.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant could
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by the warranty. Always
use DEX-COOL
®(silicate-free) coolant in the vehicle.
5-30

How to Add Coolant to the Coolant
Surge Tank
If you have not found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is visible
but the coolant level is not at or above the FULL COLD
mark, add a 50/50 mixture of clean, drinkable water
and DEX-COOL
®coolant at the coolant surge tank,
but be sure the cooling system, including the coolant
surge tank pressure cap, is cool before you do it.
SeeEngine Coolant on page 5-24for more information.
If no coolant is visible in the surge tank, add coolant
as follows:
{CAUTION:
Steam and scalding liquids from a hot cooling
system can blow out and burn you badly. They
are under pressure, and if you turn the radiator
pressure cap — even a little — they can come
out at high speed. Never turn the cap when the
cooling system, including the radiator pressure
cap, is hot. Wait for the cooling system and
radiator pressure cap to cool if you ever have
to turn the pressure cap.
{CAUTION:
Adding only plain water to the cooling system
can be dangerous. Plain water, or some other
liquid such as alcohol, can boil before the
proper coolant mixture will. The vehicle’s
coolant warning system is set for the proper
coolant mixture. With plain water or the wrong
mixture, the engine could get too hot but you
would not get the overheat warning. The
engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.
Notice:In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
5-31

Child Restraints
Child Restraint Systems...............................1-43
Infants and Young Children...........................1-39
Lower Anchors and Tethers for Children..........1-47
Older Children.............................................1-36
Securing a Child Restraint in a
Rear Seat Position...................................1-57
Securing a Child Restraint in the
Right Front Seat Position..........................1-60
Where to Put the Restraint...........................1-46
Cigarette Lighter.............................................3-21
Cleaning
Aluminum Wheels......................................5-106
Exterior Lamps/Lenses................................5-104
Fabric/Carpet............................................5-101
Finish Care...............................................5-104
Instrument Panel, Vinyl, and Other
Plastic Surfaces.....................................5-102
Interior.....................................................5-100
Leather....................................................5-102
Speaker Covers.........................................5-103
Tires........................................................5-106
Underbody Maintenance.............................5-107
Washing Your Vehicle.................................5-103
Weatherstrips............................................5-103
Windshield, Backglass, and Wiper Blades......5-105
Wood Panels............................................5-103Climate Control System
Dual Automatic............................................3-22
Outlet Adjustment........................................3-29
Rear Air Conditioning and Heating System,
Electronic................................................3-29
Clock............................................................3-21
Clock, Setting.................................................3-73
Collision Damage Repair..................................7-10
Compass.......................................................2-45
Content Theft-Deterrent....................................2-24
Control of a Vehicle.......................................... 4-3
Coolant
Engine Temperature Gage
............................3-40
Heater, Engine............................................2-31
Surge Tank Pressure Cap.............................5-26
Cooling System..............................................5-29
Cruise Control................................................3-12
Cruise Control Light........................................3-46
Cupholder(s)..................................................2-64
Customer Assistance Information
Courtesy Transportation.................................. 7-9
Customer Assistance for
Text Telephone (TTY) Users........................ 7-4
Customer Assistance Offices........................... 7-5
Customer Satisfaction Procedure..................... 7-2
GM Mobility Reimbursement Program............... 7-6
Reporting Safety Defects to General Motors....7-14
3

E
EDR .............................................................7-16
Electrical System
Add-On Equipment.....................................5-110
Center Instrument Panel Fuse Block.............5-112
Fuses and Circuit Breakers.........................5-110
Instrument Panel Fuse Block.......................5-111
Power Windows and Other Power Options....5-110
Underhood Fuse Block...............................5-113
Windshield Wiper Fuses.............................5-110
Electronically Controlled Air Suspension System . . . 4-54
Engine
Air Cleaner/Filter.........................................5-18
Check and Service Engine Soon Light............3-42
Coolant......................................................5-24
Coolant Heater............................................2-31
Coolant Temperature Gage...........................3-40
Drive Belt Routing.......................................6-15
Engine Compartment Overview......................5-12
Exhaust.....................................................2-43
Fan Noise..................................................5-33
Oil .............................................................5-13
Oil Life System...........................................5-16
Overheated Protection Operating Mode...........5-28
Overheating................................................5-27
Running While Parked..................................2-44
Starting......................................................2-30Entry/Exit Lighting...........................................3-19
Event Data Recorders.....................................7-16
Extender, Safety Belt.......................................1-35
Exterior Lamps...............................................3-15
F
Filter
Engine Air Cleaner......................................5-18
Finish Damage.............................................5-107
First Aid Kit....................................................4-42
Fixed Mast Antenna.......................................3-118
Flashers, Hazard Warning.................................. 3-6
Flash-to-Pass................................................... 3-9
Flat Tire........................................................5-78
Flat Tire, Changing.........................................5-78
Flat Tire, Storing.....................................5-94, 5-96
Fluid.............................................................5-21
Power Steering...........................................5-34
Windshield Washer......................................5-35
Folding Rear Seat............................................ 1-8
Four-Wheel Drive............................................5-46
Four-Wheel Drive, Full-Time.............................2-36
Front Axle......................................................5-47
Front Mounted Receiver...................................4-43
5

Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-5
Filling a Portable Fuel Container..................... 5-9
Filling the Tank............................................. 5-7
Fuels in Foreign Countries.............................. 5-6
Gage.........................................................3-47
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-5
Low Warning Light.......................................3-48
Fuses
Center Instrument Panel Fuse Block.............5-112
Fuses and Circuit Breakers.........................5-110
Instrument Panel Fuse Block.......................5-111
Underhood Fuse Block...............................5-113
Windshield Wiper.......................................5-110
G
Gage
Engine Coolant Temperature.........................3-40
Fuel..........................................................3-47
Oil Pressure...............................................3-45
Speedometer..............................................3-33
Tachometer.................................................3-33
Voltmeter Gage...........................................3-37
Garage Door Opener.......................................2-57
Gasoline
Octane........................................................ 5-5
Specications............................................... 5-5Glove Box.....................................................2-64
GM Mobility Reimbursement Program.................. 7-6
H
Hazard Warning Flashers................................... 3-6
Head Restraints............................................... 1-7
Headlamps....................................................5-48
Bulb Replacement.......................................5-48
Daytime Running Lamps.......................3-17, 5-50
Exterior Lamps............................................3-15
Flash-to-Pass............................................... 3-9
Front Turn Signal and Parking Lamps.............5-49
Halogen Bulbs............................................5-48
High/Low Beam Changer................................ 3-8
On Reminder..............................................3-17
Roof Marker Lamps.....................................5-50
Heated Seats................................................... 1-4
Heater...........................................................3-22
Highbeam On Light.........................................3-47
Highway Hypnosis...........................................4-34
Hill and Mountain Roads..................................4-35
Hood
Checking Things Under.................................. 5-9
Release.....................................................5-10
Horn............................................................... 3-6
How to Wear Safety Belts Properly...................1-22
6