2008 HUMMER H2 lock

Remember: ABS does not change the time you need to
get your foot up to the brake pedal or always decrease
stopping distance. If you get too close to the vehicle
in front of you, you will not have time to apply the brakes
if that vehicle suddenly slows or stops. Always leave
enough room up ahead to stop, even though you
have ABS.
Using ABS
Do not pump the brakes. Just hold the brake pedal down
rmly and let antilock work for you. You might feel the
brakes vibrate or notice some noise, but this is normal.
Braking in Emergencies
With ABS, you can steer and brake at the same time.
In many emergencies, steering can help you more than
even the very best braking.
Traction Control System (TCS)
Your vehicle has a Traction Control System (TCS) that
limits wheel spin. This is especially useful in slippery
road conditions. The system operates only if it senses
that any of the wheels are spinning or beginning to lose
traction. When this happens, the system applies the
brakes to limit wheel spin and also reduces engine
power. You may feel or hear the system working, but
this is normal.TCS may operate on dry roads under some conditions.
When this happens, you may notice a reduction in
acceleration or a pumping sound. This is normal and
does not mean there’s a problem with your vehicle.
Examples of these conditions include hard acceleration
in a turn, an abrupt upshift or downshift of the
transmission or driving on rough roads.
If your vehicle is in cruise control when the TCS begins
to limit wheel spin, the cruise control will automatically
disengage. When road conditions allow you to safely
use it again, you may re-engage the cruise control.
SeeCruise Control on page 3-12.
If your vehicle has a Driver information Center (DIC),
a SERVICE TRACTION CONTROL message will appear
when a Traction Control System or Antilock Brake
System problem has been detected and the vehicle
needs service. SeeDIC Warnings and Messages
on page 3-56.
When this message is on, the system will not limit
wheel spin. Adjust your driving accordingly.
The traction control system automatically comes on
whenever you start your vehicle. To limit wheel
spin, especially in slippery road conditions, you should
always leave the system on. But you can turn the
traction control system off if you ever need to.
4-5

To turn the system off,
press the TCS button for
ve seconds.
This light will come on
steady when the traction
control system has been
turned off. This light
ashes when TCS is
active.
If you press the TCS button, the traction control system
will turn off and a TRACTION CONTROL OFF
message will appear on the DIC. Press the TCS button
again to turn the system back on. The TRACTION
CONTROL OFF message will then go off. The Traction
Control System will reset itself at each ignition cycle.
Adding non-dealer/non-retailer accessories can
affect your vehicle’s performance. SeeAccessories and
Modifications on page 5-3.Locking Rear Axle
The locking rear axle can give the vehicle additional
traction from the rear wheels when traveling in off-road
situations such as mud, snow, sand, steep hills and
uneven terrain.
The button used to turn
this feature on or off is
located below the transfer
case dial to the right of
the steering wheel.
To lock the rear axle:
1. Place the transfer case in the Four-Wheel-Low Lock
mode. This is the only mode which will allow the rear
axle to lock. SeeFull-Time Four-Wheel Drive on
page 2-36for more information regarding the transfer
case and Four-Wheel-Low-Lock mode.
2. Press the button with the vehicle stopped or moving
less than 2 mph (3 km/h).
4-6

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

It is better to remove as much speed as you can from a
possible collision. Then steer around the problem, to
the left or right depending on the space available.
An emergency like this requires close attention and a
quick decision. If you are holding the steering wheel at
the recommended 9 and 3 o’clock positions, you
can turn it a full 180 degrees very quickly without
removing either hand. But you have to act fast, steer
quickly, and just as quickly straighten the wheel
once you have avoided the object.
The fact that such emergency situations are always
possible is a good reason to practice defensive driving
at all times and wear safety belts properly.Off-Road Recovery
You may nd that your right wheels have dropped off
the edge of a road onto the shoulder while you are
driving.
If the level of the shoulder is only slightly below the
pavement, recovery should be fairly easy. Ease off
the accelerator and then, if there is nothing in the way,
steer so that your vehicle straddles the edge of the
pavement. You can turn the steering wheel up to
one-quarter turn until the right front tire contacts the
pavement edge. Then turn the steering wheel to
go straight down the roadway.
4-11

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

Always carry a litter bag — make sure all refuse is
removed from any campsite before leaving.
Take extreme care with open res where permitted,
camp stoves, and lanterns.
Never park your vehicle over dry grass or other
combustible materials that could catch re from
the heat of the vehicle’s exhaust system.
Traveling to Remote Areas
It makes sense to plan your trip, especially when going
to a remote area. Know the terrain and plan your
route. You are much less likely to get bad surprises.
Get accurate maps of trails and terrain. Try to learn of
any blocked or closed roads.
It is also a good idea to travel with at least one other
vehicle. If something happens to one of them, the other
can help quickly.
Does your vehicle have a winch? If so, be sure to read
the winch instructions. In a remote area, a winch
can be handy if you get stuck. But you will want to know
how to use it properly.
High Mobility Characteristics
The HUMMER H2 has a 10 inch (25.4 cm) running
ground clearance (A) and a 9 inch (22.8 cm) axle
to ground clearance (B) while maintaining a low
silhouette and a low center of gravity.
4-15

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