wheel HUMMER H2 2006 Repair Manual

Tow/Haul Mode
Tow/haul mode is used when using your vehicle to pull
a large or heavy load or trailer. Tow/haul is also
useful while pulling a load in rolling terrain, in
stop-and-go traffic, or when you need improved
low-speed control, such as when parking. The purpose
of the tow/haul mode is to do the following:
Reduce the frequency and improve the predictability
of transmission shifts when pulling a heavy trailer or
a large or heavy load.
Provide the same solid shift feel when pulling a
heavy trailer or a large or heavy load as when
the vehicle is unloaded.
Improve control of vehicle speed while requiring
less accelerator pedal activity when pulling a
heavy trailer or a large or heavy load.
Tow/haul mode is most effective when the vehicle and
trailer combined weight is at least 75 percent of the
vehicle’s Gross Combination Weight Rating (GCWR).
See “Weight of the Trailer” later in this section.Press the button on the
instrument panel to the
right of the steering
wheel to enable the
tow/haul mode.
A light on the instrument
panel will illuminate to
indicate that tow/haul
mode has been selected.
Press the button again to turn off tow/haul mode. The
indicator light on the instrument panel will turn off.
The vehicle will automatically turn off tow/haul mode
every time it is started.
Driving with tow/haul mode activated without a heavy
load or with no trailer will cause reduced fuel economy
and unpleasant engine and transmission driving
characteristics, but will not cause damage.
4-65

Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For
example, speed, altitude, road grades, outside
temperature and how much your vehicle is used to pull
a trailer are all important. It can also depend on any
special equipment that you have on your vehicle,
and the amount of tongue weight the vehicle can carry.
See “Weight of the Trailer Tongue” later in this
section for more information.Maximum trailer weight is calculated assuming only the
driver is in the tow vehicle and it has all the required
trailering equipment. The weight of additional optional
equipment, passengers and cargo in the tow vehicle
must be subtracted from the maximum trailer weight.
Use the following chart to determine how much
your vehicle can weigh, based upon your vehicle model
and options.
Engine Axle Ratio Maximum Trailer Weight **GCWR
6000 V8 (SUV) 4.10 6,700 lbs (3 039 kg) 13,500 lbs (6 123 kg)
6000 V8 (SUT)* 4.10 6,600 lbs (2 994 kg) 13,500 lbs (6 123 kg)
**The Gross Combination Weight Rating (GCWR) in the total allowable weight of the completely loaded vehicle and
trailer including any passengers, cargo, equipment and conversions. The GCWR for your vehicle should not be
exceeded.
*Sport utility truck (SUT) models are neither designed nor intended to tow 5th wheel or gooseneck trailers.
You can ask your dealer for our trailering information or
advice, or you can write us at the address listed in
your Warranty and Owner Assistance Information
Booklet.In Canada, write to:
General Motors of Canada Limited
Customer Communication Centre, 163-005
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
4-66

Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, just move that hand
to the left. To move the trailer to the right, move your
hand to the right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you’re turning with a trailer, make wider turns than
normal. Do this so your trailer won’t strike soft shoulders,
curbs, road signs, trees or other objects. Avoid jerky or
sudden maneuvers. Signal well in advance.
Turn Signals When Towing a Trailer
The arrows on your instrument panel will ash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also ash, telling other drivers
you’re about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
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.
4-72

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.
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
start your engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store
the chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission uid (don’t overll),
engine oil, axle lubricant, belts, cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you nd them quickly. If
you’re trailering, it’s a good idea to review these sections
before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
4-73

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................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 the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-14
Engine Oil Life System..................................5-17
Engine Air Cleaner/Filter................................5-19
Automatic Transmission Fluid.........................5-22
Engine Coolant.............................................5-24
Coolant Surge Tank Pressure Cap..................5-26
Engine Overheating.......................................5-27
Overheated Engine Protection
Operating Mode........................................5-28Cooling System............................................5-29
Power Steering Fluid.....................................5-33
Windshield Washer Fluid................................5-34
Brakes........................................................5-35
Battery........................................................5-38
Jump Starting...............................................5-39
Rear Axle.......................................................5-43
Four-Wheel Drive............................................5-44
Front Axle......................................................5-45
Bulb Replacement..........................................5-46
Halogen Bulbs..............................................5-46
Headlamps..................................................5-47
Front Turn Signal and Parking Lamps..............5-48
Daytime Running Lamps (DRL).......................5-48
Roof Marker Lamps......................................5-49
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps.........................................5-50
Replacement Bulbs.......................................5-51
Windshield Wiper Blade Replacement..............5-52
Tires..............................................................5-53
Tire Sidewall Labeling...................................5-54
Tire Terminology and Denitions.....................5-57
Ination - Tire Pressure.................................5-59
Tire Inspection and Rotation...........................5-61
When It Is Time for New Tires.......................5-62
Section 5 Service and Appearance Care
5-1

Buying New Tires.........................................5-63
Different Size Tires and Wheels......................5-64
Uniform Tire Quality Grading..........................5-65
Wheel Alignment and Tire Balance..................5-66
Wheel Replacement......................................5-66
Tire Chains..................................................5-67
Accessory Inator.........................................5-68
If a Tire Goes Flat........................................5-69
Changing a Flat Tire.....................................5-70
Removing the Spare Tire and Tools (SUT).......5-71
Removing the Spare Tire and Tools (SUV).......5-78
Removing the Flat Tire and Installing the
Spare Tire (SUT and SUV).........................5-83
Storing a Flat or Spare Tire and
Tools (SUT)..............................................5-96
Storing a Flat or Spare Tire and
Tools (SUV)............................................5-101
Spare Tire.................................................5-105
Appearance Care..........................................5-105
Cleaning the Inside of Your Vehicle...............5-105
Fabric/Carpet..............................................5-107
Leather......................................................5-107
Instrument Panel, Vinyl, and Other
Plastic Surfaces.......................................5-108
Wood Panels..............................................5-108
Speaker Covers..........................................5-108Care of Safety Belts....................................5-108
Weatherstrips.............................................5-108
Washing Your Vehicle..................................5-109
Cleaning Exterior Lamps/Lenses....................5-109
Finish Care................................................5-110
Windshield, Backglass, and Wiper Blades.......5-110
Aluminum Wheels.......................................5-111
Tires.........................................................5-111
Sheet Metal Damage...................................5-112
Finish Damage...........................................5-112
Underbody Maintenance...............................5-112
Chemical Paint Spotting...............................5-112
Vehicle Care/Appearance Materials................5-113
Vehicle Identication.....................................5-114
Vehicle Identication Number (VIN)................5-114
Service Parts Identication Label...................5-114
Electrical System..........................................5-114
Add-On Electrical Equipment.........................5-114
Windshield Wiper Fuses...............................5-115
Power Windows and Other Power Options......5-115
Fuses and Circuit Breakers..........................5-115
Instrument Panel Fuse Block........................5-116
Center Instrument Panel Fuse Block..............5-118
Underhood Fuse Block................................5-119
Capacities and Specications........................5-124
Section 5 Service and Appearance Care
5-2

Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built-in wear indicators that make
a high-pitched warning sound when the brake pads
are worn and new pads are needed. The sound
may come and go or be heard all the time your vehicle
is moving, except when you are pushing on the
brake pedal rmly.
{CAUTION:
The brake wear warning sound means that soon
your brakes will not work well. That could lead
to an accident. When you hear the brake wear
warning sound, have your vehicle serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.Some driving conditions or climates may cause a brake
squeal when the brakes are rst applied or lightly
applied. This does not mean something is wrong with
your brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts in
the proper sequence to GM torque specications.
Brake linings should always be replaced as complete
axle sets.
Brake Pedal Travel
See your dealer if the brake pedal does not return to
normal height, or if there is a rapid increase in
pedal travel. This could be a sign of brake trouble.
Brake Adjustment
Every time you make a brake stop, your disc brakes
adjust for wear.
5-37

How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
When the differential is cold, the proper level is from
5/8 inch to 1-5/8 inch (15 mm to 40 mm) below the
bottom of the ller plug hole, located on the rear axle.
Add only enough uid to reach the proper level.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. SeeRecommended Fluids
and Lubricants on page 6-12.
Four-Wheel Drive
Transfer Case
It is not necessary to regularly check transfer case uid
unless you suspect there is a leak or you hear an
unusual noise. A uid loss could indicate a problem.
Have it inspected and repaired.
Refer to the Maintenance Schedule to determine how
often to change the lubricant. SeeScheduled
Maintenance on page 6-4.
5-44

Front Turn Signal and
Parking Lamps
To replace a front turn signal or parking lamp bulb, do
the following:
1. Open the hood. SeeHood Release on page 5-11
for more information.
2. Locate the bulb you need to change.
3. Turn the bulb socket
counterclockwise and
remove it from the
lamp housing.
4. Pull the bulb from the bulb socket.
5. Install the new bulb into the bulb socket.
6. Reinstall the bulb socket into the lamp housing and
turn it clockwise until it locks.
Daytime Running Lamps (DRL)
To replace a daytime running lamp bulb, do
the following:
1. Locate the lamp
assembly behind the
front bumper. It is
easiest to come in from
the side of the
vehicle through the
wheel opening.
2. Turn the bulb socket counterclockwise and remove
it from the lamp housing.
3. Remove the bulb from the bulb socket.
4. Install the new bulb into the bulb socket.
5. Reinstall the bulb socket into the lamp housing and
turn it clockwise until it locks.
5-48

Tire Size
The following examples show the different parts of a
tire size.
(A) Passenger (P-Metric) Tire:The United States
version of a metric tire sizing system. The letter P as the
rst character in the tire size means a passenger
vehicle tire engineered to standards set by the U.S. Tire
and Rim Association.(A) Light Truck (LT-Metric) Tire:The United States
version of a metric tire sizing system. The letters LT as
the rst two characters in the tire size means a light
truck tire engineered to standards set by the U.S. Tire
and Rim Association.
(B) Tire Width:The three-digit number indicates the
tire section width in millimeters from sidewall to sidewall.
(C) Aspect Ratio:A two-digit number that indicates
the tire height-to-width measurements. For example, if
the tire size aspect ratio is 75, as shown in item C of the
light truck (LT-Metric) tire illustration, it would mean
that the tire’s sidewall is 75% as high as it is wide.
(D) Construction Code:A letter code is used to
indicate the type of ply construction in the tire. The letter
R means radial ply construction; the letter D means
diagonal or bias ply construction; and the letter B means
belted-bias ply construction.
(E) Rim Diameter:Diameter of the wheel in inches.
(F) Service Description:The service description
indicates the load range and speed rating of a tire. The
load index can range from 1 to 279. Speed ratings
range from A to Z. Passenger (P-Metric) Tire
Light Truck (LT-Metric) Tire
5-56