brake light HUMMER H2 2008 User Guide

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

For persons under 21, it is against the law in every
U.S. state to drink alcohol. There are good medical,
psychological, and developmental reasons for
these laws.
The obvious way to eliminate the leading highway
safety problem is for people never to drink alcohol and
then drive.
Medical research shows that alcohol in a person’s
system can make crash injuries worse, especially
injuries to the brain, spinal cord, or heart. This means
that when anyone who has been drinking — driver
or passenger — is in a crash, that person’s chance of
being killed or permanently disabled is higher than if
the person had not been drinking.
Control of a Vehicle
The following three systems help to control your vehicle
while driving — brakes, steering, and accelerator.
At times, as when driving on snow or ice, it is easy to ask
more of those control systems than the tires and road can
provide. Meaning, you can lose control of your vehicle.
SeeTraction Control System (TCS) on page 4-5.
Adding non-dealer/non-retailer accessories can affect
your vehicle’s performance. SeeAccessories and
Modifications on page 5-3.
Braking
SeeBrake System Warning Light on page 3-38.
Braking action involves perception time and reaction
time. First, you have to decide to push on the brake
pedal. That is perception time. Then you have to bring
up your foot and do it. That is reaction time.
Average reaction time is about three-fourths of a
second. But that is only an average. It might be less
with one driver and as long as two or three seconds or
more with another. Age, physical condition, alertness,
coordination, and eyesight all play a part. So do alcohol,
drugs, and frustration. But even in three-fourths of a
second, a vehicle moving at 60 mph (100 km/h) travels
66 feet (20 m). That could be a lot of distance in an
emergency, so keeping enough space between
your vehicle and others is important.
And, of course, actual stopping distances vary greatly
with the surface of the road, whether it is pavement
or gravel; the condition of the road, whether it is
wet, dry, or icy; tire tread; the condition of the brakes;
the weight of the vehicle; and the amount of brake force
applied.
4-3

Avoid needless heavy braking. Some people drive
in spurts — heavy acceleration followed by heavy
braking — rather than keeping pace with traffic. This
is a mistake. The brakes might not have time to
cool between hard stops. The brakes will wear out
much faster if you do a lot of heavy braking. If you
keep pace with the traffic and allow realistic following
distances, you will eliminate a lot of unnecessary
braking. That means better braking and longer
brake life.
Adding non-dealer/non-retailer accessories can affect
your vehicle’s performance. SeeAccessories and
Modifications on page 5-3.
Antilock Brake System (ABS)
Your vehicle has the Antilock Brake System (ABS),
an advanced electronic braking system that will
help prevent a braking skid.
When you start the engine and begin to drive away,
ABS will check itself. You might hear a momentary
motor or clicking noise while this test is going on.
This is normal.If there is a problem with
the ABS, this warning light
will stay on. SeeAntilock
Brake System Warning
Light on page 3-39.
Let us say the road is wet and you are driving safely.
Suddenly, an animal jumps out in front of you. You slam
on the brakes and continue braking. Here is what
happens with ABS:
A computer senses that wheels are slowing down. If
one of the wheels is about to stop rolling, the computer
will separately work the brakes at each front wheel
and at both rear wheels.
ABS can change the brake pressure faster than any
driver could. The computer is programmed to make the
most of available tire and road conditions. This can
help you steer around the obstacle while braking hard.
As you brake, the computer keeps receiving updates
on wheel speed and controls braking pressure
accordingly.
4-4

You must wait for the light in the button to stop ashing
and remain illuminated before the rear axle is locked.
Notice:If you try to lock the rear axle while your
vehicle is stuck and the tires are spinning, you could
damage your vehicle’s drivetrain. The repairs
would not be covered by your warranty. Always lock
the rear axle before attempting situations and/or
navigating terrain which could possibly cause
the vehicle to become stuck.
The locking rear axle will be disengaged when the
vehicle’s speed is greater than 40 mph (64 km/h), if the
vehicle’s battery is low and/or the transfer case is
shifted out of Four-Wheel-Low-Lock mode.
Notice:If you lock the rear axle while driving
on pavement, you could damage your vehicle’s
drivetrain. The repairs would not be covered by
your warranty. Do not use the locking rear axle
on pavement.
StabiliTrak®System
Your vehicle has the StabiliTrak®system which
combines Antilock brake, traction and stability control
systems and helps the driver maintain directional control
of the vehicle in most driving conditions.When you rst start your vehicle and begin to drive
away, the system performs several diagnostic checks to
ensure there are no problems. You may hear or feel
the system working. This is normal and does not mean
there is a problem with your vehicle. The system
should initialize before the vehicle reaches 20 mph
(32 km/h). In some cases, it may take approximately
two miles of driving before the system initializes.
If the system fails to turn on or activate, the StabiliTrak
®
light along with one of the following messages will be
displayed on the Driver Information Center (DIC):
TRACTION CONTROL OFF, SERVICE TRACTION
CONTROL, STABILITRAK OFF, SERVICE
STABILITRAK. If these DIC messages appear, make
sure the StabiliTrak
®system has not been turned
off using the StabiliTrak®on/off button. If this clears
the message(s), your vehicle does not need servicing.
If this does not clear the message(s), then turn the
vehicle off, wait 15 seconds, and then turn it back on
again to reset the system. If any of these messages still
appear on the Driver Information Center (DIC), your
vehicle should be taken in for service. For more
information on the DIC messages, seeDriver
Information Center (DIC) on page 3-49.
4-7

The StabiliTrak®light will
ash on the instrument
panel cluster when
the system is both on
and activated.
You may also feel or hear the system working; this is
normal.
The traction control disable
button is located on the
instrument panel below the
climate controls.
The traction control part of StabiliTrak
®can be turned
off by pressing and releasing the StabiliTrak®button
if both systems (traction control and StabiliTrak®) were
previously on. To disable both traction control and
StabiliTrak
®, press and hold the button for ve seconds.
Traction control and StabiliTrak
®can be turned on
by pressing and releasing the StabiliTrak®button if
not automatically shut off for any other reason.When the TCS or StabiliTrak
®system is turned off,
the StabiliTrak®light and the appropriate TCS off
or StabiliTrak®off message will be displayed on the
DIC to warn the driver. Your vehicle will still have
brake-traction control when traction control is off, but
will not be able to use the engine speed management
system. See “Traction Control Operation” next for
more information.
When the traction control system has been turned off,
you may still hear system noises as a result of the
brake-traction control coming on.
It is recommended to leave the system on for normal
driving conditions, but it may be necessary to turn
the system off if your vehicle is stuck in sand, mud,
ice or snow, and you want to “rock” your vehicle
to attempt to free it. It may also be necessary to turn
off the system when driving in extreme off-road
conditions where high wheel spin is required. SeeIf
Your Vehicle is Stuck in Sand, Mud, Ice, or Snow
on page 4-39.
When the transfer case is in Four-Wheel-Low Lock,
the stability system is automatically disabled, the
StabiliTrak
®light will come on and the STABILITRAK
OFF message will appear on the DIC. Both traction
control and StabiliTrak
®are automatically disabled in
this condition.
4-8

Traction Control Operation
The traction control system is part of the StabiliTrak®
system. Traction control limits wheel spin by reducing
engine power to the wheels (engine speed management)
and by applying brakes to each individual wheel
(brake-traction control) as necessary.
The traction control system is enabled automatically
when you start your vehicle. It will activate and the
StabiliTrak
®light will ash if it senses that any of the
wheels are spinning or beginning to lose traction while
driving. If you turn off traction control, only the
brake-traction control portion of traction control will
work. The engine speed management will be disabled.
In this mode, engine power is not reduced automatically
and the driven wheels can spin more freely. This can
cause the brake-traction control to activate constantly.
Notice:If you allow the wheel(s) of one axle to spin
excessively while the StabiliTrak
®, ABS and brake
warning lights and the SERVICE STABILITRAK
message are displayed, you could damage the
transfer case. The repairs would not be covered by
your warranty. Reduce engine power and do not
spin the wheel(s) excessively while these lights and
this message are displayed.The traction control system may activate on dry or
rough roads or under conditions such as heavy
acceleration while turning or abrupt upshifts/downshifts
of the transmission. When this happens, you may notice
a reduction in acceleration, or may hear a noise or
vibration. This is normal.
If your vehicle is in cruise control when the system
activates, the StabiliTrak
®light will ash and the cruise
control will automatically disengage. When road
conditions allow you to use cruise again, you may
re-engage the cruise control. SeeCruise Control on
page 3-12.
StabiliTrak
®may also turn off automatically if it
determines that a problem exists with the system.
If the problem does not clear itself after restarting the
vehicle, you should see your dealer/retailer for service.
Steering
Power Steering
If you lose power steering assist because the engine
stops or the system is not functioning, you can steer but
it will take much more effort.
4-9

While driving on a surface with reduced traction,
try your best to avoid sudden steering, acceleration,
or braking, including reducing vehicle speed by shifting
to a lower gear. Any sudden changes could cause
the tires to slide. You might not realize the surface
is slippery until your vehicle is skidding. Learn to
recognize warning clues — such as enough water,
ice, or packed snow on the road to make a mirrored
surface — and slow down when you have any doubt.
Remember: Any Antilock Brake System (ABS) helps
avoid only the braking skid.
Off-Road Driving
This off-road guide is meant to provide advice for when
you drive your vehicle off paved roads. Also, see
Braking on page 4-3.
The airbag system is designed to work properly under a
wide range of conditions, including off-road usage.
Observe safe driving speeds, especially on rough
terrain. As always, wear your safety belt.
Off-road driving can be great fun. But it does have
some denite hazards. The greatest of these is
the terrain itself.“Off-roading” means you have left the great North
American road system behind. Traffic lanes are not
marked. Curves are not banked. There are no
road signs. Surfaces can be slippery, rough, uphill or
downhill. In short, you have gone right back to nature.
Off-road driving involves some new skills. And that
is why it is very important that you read this guide.
You will nd many driving tips and suggestions. These
will help make your off-road driving safer and more
enjoyable.
Before You Go Off-Roading
There are some things to do before you go out. For
example, be sure to have all necessary maintenance
and service work done. Check to make sure all
underbody shields are properly attached. Remove any
removable side steps. SeeAssist Steps on page 4-32.
Make sure any equipment you may need — rst aid
kit, cell phone, ashlight, etc. — is securely stored in the
vehicle. Be sure you read all the information about
your four-wheel-drive vehicle in this manual. Is there
enough fuel? Is the spare tire fully inated? Are the uid
levels up where they should be? What are the local
laws that apply to off-roading where you will be driving?
If you do not know, you should check with law
enforcement people in the area. Will you be on
someone’s private land? If so, be sure to get the
necessary permission.
4-13

Brake and Accelerator Operation
Techniques for Off-Road Driving
For logs, walls, rocks, severe ditches,
hills, sand, etc.
1. Bring the vehicle to a complete stop. Do not rev
the engine.
2. Select the proper transmission and transfer case
gear range; usually FIRST (1) gear, 4LO LOCK
for such obstacles.
3. If wheel spin is experienced, maintain steady
throttle, with your foot off the brake pedal, to
allow the Traction Control System (TCS) to control
the wheel spin. TCS might not operate if the
brakes are applied.
4. If wheel spin cannot be controlled by the TCS
system, fully press the brake pedal with your
left foot so all wheel spin is stopped.
5. Back away from the obstacle so that a new
approach can be tried.
6. As the rst wheel crosses the obstacle, be prepared
to alternate the brake and accelerator pedal to
maintain control and avoid tire drop-off from
obstacles. Repeat this process for the other wheels.
For mounds, washouts, loose up-hill
slopes, ditches, etc.
When wheel spin occurs as the vehicle is moving, the
driver may notice a slight shaking or shuddering of
the vehicle. This should be stopped as soon as possible
to prevent damage to vehicle components. This is the
indication that a loss of traction is occurring on this
terrain. The operator should:
1. Reduce speed and apply the brakes.
2. Assess the terrain properly and adjust vehicle
speed and gear ranges accordingly: 4HI position
for higher speeds and 4LO LOCK for more torque
and lower speeds. Transmission FIRST (1) gear
is generally recommended.
3. Apply slight pressure to the brake when the shaking
or shuddering sensation is felt, keeping the vehicle
moving in a controlled manner.
4. Be prepared to alternate between braking and
accelerating through the adverse terrain.
4-18

Driving Downhill
When off-roading takes you downhill, you will want to
consider a number of things:
How steep is the downhill? Will I be able to maintain
vehicle control?
What is the surface like? Smooth? Rough?
Slippery? Hard-packed dirt? Gravel?
Are there hidden surface obstacles? Ruts? Logs?
Boulders?
What is at the bottom of the hill? Is there a hidden
creek bank or even a river bottom with large rocks?
If you decide you can go down a hill safely, then try to
keep your vehicle headed straight down, and use a
low gear. This way, engine drag can help your brakes
and they will not have to do all the work. Descend
slowly, keeping your vehicle under control at all times.
{CAUTION:
Heavy braking when going down a hill can
cause your brakes to overheat and fade.
This could cause loss of control and a serious
accident. Apply the brakes lightly when
descending a hill and use a low gear to keep
vehicle speed under control.There some things not to do when driving down a hill.
These are important because, if you ignore them,
you could lose control and have a serious accident:
When driving downhill, avoid turns that take
you across the incline of the hill. A hill that is
not too steep to drive down may be too steep to
drive across. You could roll over if you do not
drive straight down.
Never go downhill with the transmission in
NEUTRAL (N). This is called “free-wheeling.”
Your brakes will have to do all the work and
could overheat and fade.
Your vehicle is much more likely to stall when going
uphill. But if it happens when going downhill:
1. Stop your vehicle by applying the regular brakes.
Apply the parking brake.
2. Shift to PARK (P) and, while still braking, restart the
engine.
3. Shift back to a low gear, release the parking brake,
and drive straight down.
4. If the engine will not start, get out and get help.
4-27

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