suspension HUMMER H2 2008 Owners Manual

SERVICE AIR BAG
This message displays if there is a problem with
the airbag system. Have your dealer/retailer inspect
the system for problems. SeeAirbag Readiness Light
on page 3-34andAirbag System on page 1-64for
more information.
SERVICE BATTERY CHARGING
SYSTEM
On some vehicles, this message displays if there is a
problem with the battery charging system. Under certain
conditions, the charging system light may also turn
on in the instrument panel cluster. SeeCharging System
Light on page 3-37. Driving with this problem could
drain the battery. Turn off all unnecessary accessories.
Have the electrical system checked as soon as
possible. See your dealer/retailer.
SERVICE BRAKE SYSTEM
This message displays along with the brake system
warning light if there is a problem with the brake system.
SeeBrake System Warning Light on page 3-38. If this
message appears, stop as soon as possible and
turn off the vehicle. Restart the vehicle and check for
the message on the DIC display. If the message is still
displayed or appears again when you begin driving,
the brake system needs service as soon as possible.
See your dealer/retailer.
SERVICE BRAKES SOON
This message displays if there is a problem with the
brake system. If this message appears, stop as soon
as possible and turn off the vehicle. Restart the vehicle
and check for the message on the DIC display. If the
message is still displayed or appears again when
you begin driving, the brake system needs service.
See your dealer/retailer.
SERVICE STABILITRAK
This message displays when there may be a problem
with the StabiliTrak®system. If you see this message,
try to reset the system. Stop; turn off the engine for
at least 15 seconds; then start the engine again. If this
message still comes on, it means there is a problem.
You should see your dealer/retailer for service.
The vehicle is safe to drive, however, you do not
have the benet of StabiliTrak
®, so reduce your
speed and drive accordingly.
SERVICE SUSPENSION SYSTEM
This message displays if a problem occurs with the
suspension system. If this message appears, stop as
soon as possible and turn off the vehicle. Restart
the vehicle and check for the message on the DIC
display. If the message is still displayed, or appears
again when you begin driving, there is a problem with
the air suspension system. See your dealer/retailer
for service.
3-60

Your Driving, the Road, and Your Vehicle..........4-2
Defensive Driving...........................................4-2
Drunk Driving.................................................4-2
Control of a Vehicle........................................4-3
Braking.........................................................4-3
Antilock Brake System (ABS)...........................4-4
Braking in Emergencies...................................4-5
Traction Control System (TCS).........................4-5
Locking Rear Axle..........................................4-6
StabiliTrak
®System........................................4-7
Steering........................................................4-9
Off-Road Recovery.......................................4-11
Passing.......................................................4-12
Loss of Control.............................................4-12
Off-Road Driving...........................................4-13
Assist Steps.................................................4-32
Driving at Night............................................4-32
Driving in Rain and on Wet Roads..................4-33
Before Leaving on a Long Trip.......................4-34
Highway Hypnosis........................................4-34Hill and Mountain Roads................................4-35
Winter Driving..............................................4-36
If Your Vehicle is Stuck in Sand, Mud,
Ice, or Snow.............................................4-39
Rocking Your Vehicle to Get It Out.................4-40
Recovery Loops...........................................4-40
First Aid Kit and Tool Kit...............................4-42
Front Mounted Receiver.................................4-43
Power Winch Platform...................................4-43
Loading Your Vehicle....................................4-44
Towing..........................................................4-51
Towing Your Vehicle.....................................4-51
Recreational Vehicle Towing...........................4-51
Selectable Extended Rear Ride Height.............4-53
Electronically Controlled Air Suspension
System....................................................4-54
Towing a Trailer...........................................4-55
Trailer Recommendations...............................4-67
Section 4 Driving Your Vehicle
4-1

Driving Uphill
Once you decide you can safely drive up the hill, you
need to take some special steps:
Use transmission and transfer case low gear and
get a rm grip on the steering wheel.
Get a smooth start up the hill and try to maintain
your speed. Do not use more power than you
need, because you do not want the wheels to start
spinning or sliding.
Let the traction system work to control any wheel
slippage. The traction control system allows for
moderate wheel spin with some capability to dig in
and power up the hill.
Do not continue if the vehicle shudders or exhibits
suspension hopping. This can cause damage to
the driveline or suspension components. Improper
driving technique is not covered by your vehicle
warranty.
{CAUTION:
Turning or driving across steep hills can be
dangerous. You could lose traction, slide
sideways, and possibly roll over. You could be
seriously injured or killed. When driving up
hills, always try to go straight up.
Try to drive straight up the hill if at all possible.
If the path twists and turns, you might want to
nd another route.
Ease up on your speed as you approach the top
of the hill.
Attach a ag to the vehicle to make you more
visible to approaching traffic on trails or hills.
4-24

After Off-Road Driving
Remove any brush or debris that has collected on
the underbody, chassis, or under the hood.
These accumulations can be a re hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the engine and oil
coolers for mud accumulation. Thoroughly and carefully
clean these devices to allow proper cooling. Check
the body structure, steering, suspension, wheels, tires,
and exhaust system for damage. Also, check the
fuel lines and cooling system for any leakage.
Your vehicle will require more frequent service due to
off-road use. See the Maintenance Schedule for
additional information.
Assist Steps
If your vehicle has removable side steps, remove the
steps prior to off-roading to give your vehicle more ground
clearance and to prevent damage to the vehicle from the
side steps dragging and/or catching on obstacles.
Notice:Do not drive off-road with the side steps
attached to your vehicle. You can damage the side
steps and/or your vehicle’s frame if they get
caught or drag against an obstacle. This damage
would not be covered by your vehicle’s warranty.
Always remove the side steps prior to any off-road
driving.
Driving at Night
Night driving is more dangerous than day driving because
some drivers are likely to be impaired — by alcohol or
drugs, with night vision problems, or by fatigue.
Night riving tips include:
Drive defensively.
Do not drink and drive.
Reduce headlamp glare by adjusting the inside
rearview mirror.
Slow down and keep more space between you and
other vehicles because your headlamps can only
light up so much road ahead.
Watch for animals.
When tired, pull off the road.
Do not wear sunglasses.
Avoid staring directly into approaching headlamps.
Keep the windshield and all glass on your vehicle
clean — inside and out.
Keep your eyes moving, especially during turns
or curves.
No one can see as well at night as in the daytime.
But, as we get older, these differences increase.
A 50-year-old driver might need at least twice as much
light to see the same thing at night as a 20-year-old.
4-32

The label shows the gross weight capacity of your
vehicle. This is called the GVWR (Gross Vehicle
Weight Rating). The GVWR includes the weight of
the vehicle, all occupants, fuel, and cargo.
The Certication/Tire label also tells you the
maximum weights for the front and rear axles,
called Gross Axle Weight Rating (GAWR).
To nd out the actual loads on your front and rear
axles, you need to go to a weigh station and
weigh your vehicle. Your dealer can help you with
this. Be sure to spread out your load equally on
both sides of the centerline.
Never exceed the GVWR for your vehicle, or the
GAWR for either the front or rear axle.
And, if you do have a heavy load, you should
spread it out.
{CAUTION:
Do not load your vehicle any heavier than
the Gross Vehicle Weight Rating (GVWR),
or either the maximum front or rear Gross
Axle Weight Rating (GAWR). If you do,
parts on your vehicle can break, and it
can change the way your vehicle handles.
These could cause you to lose control
and crash. Also, overloading can shorten
the life of your vehicle.
Your warranty does not cover parts or components
that fail because of overloading.
The label will help you decide how much cargo
and installed equipment your truck can carry.
Using heavier suspension components to
get added durability might not change your weight
ratings. Ask your dealer to help you load your
vehicle the right way.
4-49

Selectable Extended Rear
Ride Height
If your vehicle has this feature it comes as part of the
electronically controlled air suspension system.
The selectable rear ride height allows you to raise the
rear of the vehicle about 2 inches (5 cm) over the normal
ride height. This can be helpful when driving off-road
where you may need more ground clearance to clear
an obstacle.
The button that controls this
feature is located on the
instrument panel to the
right of the steering wheel.
To use this feature, ensure that the following conditions
are met:
The engine must be running.
All doors must be fully closed. The suspension will
not raise or lower if a door is open.
The vehicle speed must be less than 40 mph
(64 km/h). The system will not activate otherwise.Press the height control button to raise the rear of the
vehicle.
A light in the button will begin to ash as the rear of the
vehicle rises. Once the extended height has been
reached (this may take up to a minute), the warning
light will stop ashing and will stay lit while the vehicle is
at the extended height.
To lower the vehicle to the normal ride height, press the
button again. The light in the button will ash as the
suspension lowers. When the light in the button stops
ashing and goes out, the suspension has reached
the normal ride height.
This feature will lower the vehicle to the normal height if
vehicle speed exceeds 40 mph (64 km/h).
You may also want to use this feature when ascending,
descending or cresting a steep hill as this can help
prevent the rear bumper from dragging on the base of
the hill or prevent the vehicle from grounding out
(high centering) on the crest of the hill.
Do not use this feature when towing a trailer.
4-53

Electronically Controlled Air
Suspension System
The electronically controlled air suspension, if equipped,
keeps the rear of your vehicle level under all load
conditions. The system maintains the vehicle at the
currently selected ride height. There are two ride
heights: Normal Ride Height and Extended Ride Height.
The Extended Ride Height feature is only available if
the vehicle speed is below 40 mph (64 km/h). If the
vehicle is at Extended Ride Height and the speed
exceeds 40 mph (64 km/h), the system will automatically
return the vehicle to Normal Ride Height. The activation
and deactivation of the Extended Ride Height feature
is controlled by a switch on the instrument panel.
The system includes a compressor, two height sensors
and two air springs supporting the vehicle.
The system is activated when the engine is started and
deactivated when the ignition is returned to OFF.
The engine must be running for the rear of the vehicle
to be raised and the doors must be closed to enable
a transition between Normal Ride Height and Extended
Ride Height.
You may hear the compressor running whilst the system
is active and you may also hear the release of air
similar to a hissing sound. This is normal.Load leveling will not function normally with the
inater hose attached to the inator outlet. Remove
the hose from the outlet when it is not in use.
SeeAccessory Inflator on page 5-75.
Overload and Overheat Protection
Overload protection is designed to protect the air
suspension system and is an indication to the driver that
the vehicle is overloaded.
If the rear suspension remains at a low height, the rear
axle load has exceeded GAWR (Gross Axle Weight
Rating). When the overload protection mode is activated,
the compressor operates for about 30 seconds to
one minute without raising the vehicle depending on the
amount of overload. This will continue each time the
ignition is turned on until the rear axle load is reduced
below GAWR. The system may reactivate without
cycling the ignition if some of the excess load is
removed.
If the total rear GAWR (Gross Axle Weight Rating) is
reached, the suspension may be slightly less than level.
This is normal and does not mean there is a problem
with the air suspension.
4-54

In some instances the compressor may stop working
due to being overheated. This is normal. In the instance
of an abnormal overheat condition though the
compressor will stop working and the SERVICE
SUSPENSION SYSTEM will be displayed on the DIC.
SeeDIC Warnings and Messages on page 3-56for
more information.
Towing a Trailer
{CAUTION:
If you do not use the correct equipment and
drive properly, you can lose control when you
pull a trailer. For example, if the trailer is too
heavy, the brakes may not work well — or even
at all. You and your passengers could be
seriously injured. Pull a trailer only if you have
followed all the steps in this section. Ask your
dealer for advice and information about towing
a trailer with your vehicle.Notice:Pulling a trailer improperly can damage
your vehicle and result in costly repairs not covered
by your warranty. To pull a trailer correctly, follow
the advice in this part, and see your dealer for
important information about towing a trailer with
your vehicle.
To identify the trailering capacity of your vehicle, you
should read the information in “Weight of the Trailer” that
appears later in this section.
Trailering is different than just driving your vehicle by
itself. Trailering means changes in handling,
acceleration, braking, durability and fuel economy.
Successful, safe trailering takes correct equipment, and
it has to be used properly.
That is the reason for this part. In it are many
time-tested, important trailering tips and safety rules.
Many of these are important for your safety and that of
your passengers. So please read this section carefully
before you pull a trailer.
4-55

3. Remove the dust cover and attach the hose to
the outlet.
The accessory inator hose also has a built-in air
pressure gage. As soon as you start to inate
an object it will automatically read the current
pressure.
4. Press and release the switch to turn the accessory
inator on. The indicator light will remain on while
the inator is running.When you are nished using the inator, press and
release the switch to turn it off. Place the inator kit tools
and the hose back in the pouch.
If your vehicle is equipped with the air suspension
system, load leveling will not function with the inator
hose attached to the inator outlet.
{CAUTION:
Inating something too much can make it
explode, and you or others could be injured.
Be sure to read the inator instructions, and
inate any object only to its recommended
pressure.
5-77

Fuses Usage
1 Left Trailer Stop/Turn Lamp
2 Engine Controls
3Engine Control Module, Throttle
Control
4 Right Trailer Stop/Turn Lamp
5 Front Washer
6 Oxygen Sensors
7Vehicle Stability System, Antilock
Brake System-2
8 Trailer Back-up Lamps
9 Left Low-Beam Headlamp
10 Engine Control Module (Battery)
11 Fuel Injectors, Ignition Coils (Right Side)
12 Transmission Control Module (Battery)
13 Vehicle Back-up Lamps
14 Right Low-Beam Headlamp
15 Air Conditioning Compressor
16 Oxygen Sensors
17 Transmission Controls (Ignition)
18 Fuel Pump
19 Rear WasherFuses Usage
20 Fuel Injectors, Ignition Coils (Left Side)
21 Trailer Park Lamps
22 Left Park Lamps
23 Right Park Lamps
24 Horn
25 Right Side High-Beam Headlamp
26 Daytime Running Lamps (DRL)
27 Left High-Beam Headlamp
28 Sunroof
29Key Ignition System, Theft Deterrent
System
30 Windshield Wiper
31 SEO B2 Uptter Usage (Battery)
32 Electrically Controlled Air Suspension
33 Climate Controls (Battery)
34 Airbag System (Ignition)
35 Amplier
36 Audio System
37Miscellaneous (Ignition), Cruise
Control, Rear Vision Camera
38 Airbag System (Battery)
5-115