2006 HUMMER H2 heater

What Kind of Coolant to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL®coolant which will not damage
aluminum parts. If you use this coolant mixture, you do
not need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your 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:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost would not be covered by your
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core and
other parts.
If you have to add coolant more than four times a year,
have your dealer check your cooling system.
Notice:If you use extra inhibitors and/or additives
in your vehicle’s cooling system, you could
damage your vehicle. Use only the proper mixture
of the engine coolant listed in this manual for
the cooling system. SeeRecommended Fluids and
Lubricants on page 6-12for more information.
5-25

If No Steam Is Coming From
Your Engine
The ENGINE COOLANT HOT message, along with a
low coolant condition, can indicate a serious problem.
If you get an engine overheat warning, 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 4-63.
If you get the ENGINE COOLANT HOT message with
no sign of steam, try this for a minute or so:
1. Turn on your heater to full hot at the highest fan
speed and open the windows as necessary.
2. If you are in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving — DRIVE (D).
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning does not come back on, you can drive
normally.
If the warning continues and you have not stopped, pull
over, stop, and park your vehicle right away.If there is still no sign of steam, push down the
accelerator until the engine speed is about twice as fast
as normal idle speed for at least three minutes while
you are parked. If you still have the warning, turn off the
engine and get everyone out of the vehicle until it
cools down. Also, see “Overheated Engine Protection
Operating Mode” later in this section.
You may decide not to lift the hood but to get service
help right away.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates ring
groups of cylinders helps prevent engine damage. In
this mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle to
be driven to a safe place in an emergency. Driving
extended miles (km) and/or towing a trailer in the
overheat protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any repair.
The engine oil will be severely degraded. Repair the
cause of coolant loss, change the oil and reset the oil
life system. SeeEngine Oil on page 5-14.
5-28

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 FanIf 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.
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.
5-29

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. See
Overheated 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 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.
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. See
Engine 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.
5-30

{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your 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.
{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.
1. Locate the coolant
surge tank pressure
cap that has this label.
2. You can remove the coolant surge tank pressure
cap when the cooling system, including the coolant
surge tank pressure cap and upper radiator
hose, are no longer hot. Turn the pressure cap
slowly counterclockwise about one full turn.
If you hear a hiss, wait for that to stop. A hiss
means there is still some pressure left.
3. Then keep turning the pressure cap slowly, and
remove it.
5-31

Charging System Light....................................3-34
Check
Engine Light...............................................3-39
Checking Things Under the Hood......................5-10
Chemical Paint Spotting.................................5-112
Child Restraints
Child Restraint Systems...............................1-38
Infants and Young Children...........................1-35
Lower Anchors and Tethers for Children..........1-43
Older Children.............................................1-32
Securing a Child Restraint in a Rear Seat
Position..................................................1-52
Securing a Child Restraint in the Right
Front Seat Position...................................1-54
Where to Put the Restraint...........................1-42
Chime Level Adjustment.................................3-114
Cigarette Lighter.............................................3-22
Cleaning
Aluminum Wheels......................................5-111
Exterior Lamps/Lenses................................5-109
Fabric/Carpet............................................5-107
Finish Care...............................................5-110
Inside of Your Vehicle.................................5-105
Instrument Panel, Vinyl, and Other Plastic
Surfaces...............................................5-108
Leather....................................................5-107
Speaker Covers.........................................5-108
Tires........................................................5-111
Underbody Maintenance.............................5-112
Washing Your Vehicle.................................5-109Cleaning (cont.)
Weatherstrips............................................5-108
Windshield, Backglass, and Wiper Blades......5-110
Wood Panels............................................5-108
Climate Control System
Dual Automatic............................................3-22
Outlet Adjustment........................................3-28
Collision Damage Repair..................................7-11
Comfort Guides, Rear Safety Belt.....................1-29
Content Theft-Deterrent....................................2-21
Control of a Vehicle.......................................... 4-5
Coolant
Engine Temperature Gage............................3-37
Heater, Engine............................................2-26
Surge Tank Pressure Cap.............................5-26
Cooling System..............................................5-29
Cruise Control................................................3-11
Cruise Control Light........................................3-43
Customer Assistance Information
Courtesy Transportation.................................. 7-7
Customer Assistance for Text Telephone (TTY)
Users....................................................... 7-4
Customer Assistance Offices........................... 7-4
Customer Satisfaction Procedure..................... 7-2
GM Mobility Reimbursement Program............... 7-5
Reporting Safety Defects to General Motors....7-15
Reporting Safety Defects to the Canadian
Government............................................7-15
Reporting Safety Defects to the United
States Government...................................7-14
3

Engine (cont.)
Check and Service Engine Soon Light............3-39
Coolant......................................................5-24
Coolant Heater............................................2-26
Coolant Temperature Gage...........................3-37
Drive Belt Routing.......................................6-15
Engine Compartment Overview......................5-12
Exhaust.....................................................2-37
Oil .............................................................5-14
Oil Life System...........................................5-17
Overheated Protection Operating Mode...........5-28
Overheating................................................5-27
Starting......................................................2-25
Entry/Exit Lighting...........................................3-18
Event Data Recorders (EDR)............................7-10
Extender, Safety Belt.......................................1-31
Exterior Lamps...............................................3-14
F
Filter
Engine Air Cleaner......................................5-19
Finish Damage.............................................5-112
First Aid Kit....................................................4-52
Fixed Mast Antenna.......................................3-114
Flash-to-Pass................................................... 3-8
Flat Tire........................................................5-69Flat Tire, Changing.........................................5-70
Flat Tire, Storing...................................5-96, 5-101
Fluid
Automatic Transmission................................5-22
Power Steering...........................................5-33
Windshield Washer......................................5-34
Four-Wheel Drive............................................5-44
Four-Wheel Drive, Full-Time.............................2-30
Front Axle......................................................5-45
Front Mounted Receiver...................................4-53
Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-6
Filling a Portable Fuel Container....................5-10
Filling Your Tank........................................... 5-8
Fuels in Foreign Countries.............................. 5-7
Gage.........................................................3-44
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-5
Low Warning Light.......................................3-44
Fuses
Center Instrument Panel Fuse Block.............5-118
Fuses and Circuit Breakers.........................5-115
Instrument Panel Fuse Block.......................5-116
Underhood Fuse Block...............................5-119
Windshield Wiper.......................................5-115
5

G
Gage
Engine Coolant Temperature.........................3-37
Fuel..........................................................3-44
Oil Pressure...............................................3-41
Speedometer..............................................3-31
Tachometer.................................................3-31
Transmission Temperature.............................3-37
Voltmeter Gage...........................................3-34
Garage Door Opener.......................................2-50
Gasoline
Octane........................................................ 5-5
Specications............................................... 5-5
Glove Box.....................................................2-54
GM Mobility Reimbursement Program.................. 7-5
H
Hazard Warning Flashers................................... 3-6
Head Restraints............................................... 1-5
Headlamps....................................................5-47
Automatic Headlamp System.........................3-16
Bulb Replacement.......................................5-46
Daytime Running Lamps.......................3-15, 5-48
Flash-to-Pass............................................... 3-8
Front Turn Signal and Parking Lamps.............5-48Headlamps (cont.)
Halogen Bulbs............................................5-46
High/Low Beam Changer................................ 3-8
On Reminder..............................................3-15
Roof Marker Lamps.....................................5-49
Heated Seats................................................... 1-3
Heater...........................................................3-22
Highbeam On Light.........................................3-43
Highway Hypnosis...........................................4-43
Hill and Mountain Roads..................................4-44
Hood
Checking Things Under................................5-10
Release.....................................................5-11
Horn............................................................... 3-6
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-19
I
Ignition Positions.............................................2-24
Infants and Young Children, Restraints...............1-35
Ination - Tire Pressure...................................5-59
Instrument Panel
Overview..................................................... 3-4
Instrument Panel (I/P)
Brightness..................................................3-17
Cluster.......................................................3-30
6