HUMMER H2 2009 Owners Manual

Antilock Brake System (ABS)
This vehicle has the Antilock Brake System (ABS), an
advanced electronic braking system that helps prevent a
braking skid.
When the engine is started and the vehicle begins to
drive away, ABS checks itself. A momentary motor
or clicking noise might be heard while this test is going
on. This is normal.
If there is a problem with
the ABS, this warning light
stays on. SeeAntilock
Brake System (ABS)
Warning Light on
page 3-38.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 the 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 to each wheel, as
required, faster than any driver could. This can help
the driver steer around the obstacle while braking hard.
As the brakes are applied, the computer keeps
receiving updates on wheel speed and controls braking
pressure accordingly.
Remember: ABS does not change the time needed to get
a foot up to the brake pedal or always decrease stopping
distance. If you get too close to the vehicle in front of you,
there will not be enough time to apply the brakes if that
vehicle suddenly slows or stops. Always leave enough
room up ahead to stop, even with ABS.
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Using ABS
Do not pump the brakes. Just hold the brake pedal
down rmly and let antilock work. The brakes might
vibrate or some noise might be heard, but this is normal.
Braking in Emergencies
ABS allows the driver to steer and brake at the same
time. In many emergencies, steering can help more than
even the very best braking.
StabiliTrak®System
The 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 the vehicle is started and begins to move, the
system performs several diagnostic checks to insure
there are no problems. The system may be heard or felt
while it is working. This is normal and does not mean
there is a problem with the 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),
the 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), the vehicle should be
taken in for service. For more information on the DIC
messages, seeDriver Information Center (DIC) on
page 3-46.
The StabiliTrak light will
ash on the instrument
panel cluster when the
system is both on and
activated.
The system may be heard or felt while it is working; this
is normal.
4-6

The StabiliTrak 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 until STABILITRAK OFF is displayed
on the DIC and the StabiliTrak light comes on the
instrument panel.
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 traction control or StabiliTrak system is turned
off, the StabiliTrak light and the appropriate traction
control off or StabiliTrak off message will be displayed on
the DIC to warn the driver. The vehicle will still havebrake-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,
there may be 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 the vehicle is stuck in sand, mud, ice or
snow, and you want to “rock” the 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.
4-7

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 the vehicle is started. 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 the traction control is turned off, 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 the wheel(s) of one axle is allowed to
spin excessively while the StabiliTrak, ABS
and brake warning lights and any relevant DIC
messages are displayed, the transfer case could bedamaged. The repairs would not be covered by the
vehicle warranty. Reduce engine power and do
not spin the wheel(s) excessively while these lights
and messages 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, a reduction
in acceleration may be noticed, or a noise or vibration
may be heard. This is normal.
If cruise control is being used when StabiliTrak activates,
the cruise control automatically disengages. The
cruise control can be re-engaged when road conditions
allow. 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, see your
dealer/retailer for service.
4-8

Traction Control System (TCS)
The 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, TCS applies the brakes to limit wheel
spin and also reduces engine power. The system may be
heard or felt while it is working, but this is normal.
TCS can operate on dry roads under some conditions.
When this happens, the system may be heard while it is
working or a reduction in acceleration may be noticed.
This is normal and does not mean there is a problem with
the 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 cruise control is being used when TCS begins to limit
wheel spin, the cruise control automatically disengages.
The cruise control can be re-engaged when road
conditions allow. SeeCruise Control on page 3-12.SERVICE TRACTION CONTROL comes on in the
Driver information Center (DIC) 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 the vehicle is started. To limit wheel
spin, especially in slippery road conditions, the system
should always be left on. But the traction control
system can be turned off if needed. It may be necessary
to turn the system off if the vehicle is stuck in sand,
mud, ice, or snow, and you want to “rock” the vehicle to
attempt to free it. SeeIf Your Vehicle is Stuck in
Sand, Mud, Ice, or Snow on page 4-39.
4-9

To turn the system off,
press and release the
TCS button.
This light will come on
steady when the traction
control system has been
turned off. This light ashes
when TCS is active.
If the TCS button is pressed, 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
the 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 2-37for 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).
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The light in the button must stop ashing and remain
illuminated before the rear axle is locked.
Notice:If you try to lock the axle while the vehicle
is stuck and the tires are spinning, the vehicle’s
drivetrain could be damaged. The repairs would not
be covered by the vehicle warranty. Always lock
the 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 the vehicle’s axle is locked while driving
on pavement, the drivetrain could be damaged.
Repairs would not be covered by the vehicle
warranty. Do not use the locking axle on pavement.
If four-wheel drive is needed when traveling on
pavement, use only 4HI.Steering
Power Steering
If power steering assist is lost because the engine stops
or the system is not functioning, the vehicle can be
steered but it will take more effort.
Steering Tips
It is important to take curves at a reasonable speed.
Traction in a curve depends on the condition of the tires
and the road surface, the angle at which the curve is
banked, and vehicle speed. While in a curve, speed is
the one factor that can be controlled.
If there is a need to reduce speed, do it before entering
the curve, while the front wheels are straight.
Try to adjust the speed so you can drive through the
curve. Maintain a reasonable, steady speed. Wait
to accelerate until out of the curve, and then accelerate
gently into the straightaway.
4-11

Steering in Emergencies
There are times when steering can be more effective
than braking. For example, you come over a hill and nd
a truck stopped in your lane, or a car suddenly pulls out
from nowhere, or a child darts out from between parked
cars and stops right in front of you. These problems can
be avoided by braking — if you can stop in time. But
sometimes you cannot stop in time because there is no
room. That is the time for evasive action — steering
around the problem.
The vehicle can perform very well in emergencies like
these. First apply the brakes. SeeBraking on page 4-4.
It is better to remove as much speed as possible
from a 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 holding the steering wheel at the
recommended 9 and 3 o’clock positions, it can be turned
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.
4-12

Off-Road Recovery
The vehicle’s right wheels can drop off the edge of a
road onto the shoulder while 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 the vehicle straddles the edge of the pavement.
Turn the steering wheel 3 to 5 inches, 8 to 13 cm,
(about one-eighth turn) until the right front tire contacts
the pavement edge. Then turn the steering wheel to go
straight down the roadway.
Passing
Passing another vehicle on a two-lane road can be
dangerous. To reduce the risk of danger while passing:
Look down the road, to the sides, and to crossroads
for situations that might affect a successful pass.
If in doubt, wait.
Watch for traffic signs, pavement markings, and
lines that could indicate a turn or an intersection.
Never cross a solid or double-solid line on your side
of the lane.
Do not get too close to the vehicle you want to
pass. Doing so can reduce your visibility.
Wait your turn to pass a slow vehicle.
When you are being passed, ease to the right.
Loss of Control
Let us review what driving experts say about what
happens when the three control systems — brakes,
steering, and acceleration — do not have enough friction
where the tires meet the road to do what the driver has
asked.
In any emergency, do not give up. Keep trying to steer
and constantly seek an escape route or area of less
danger.
4-13

Skidding
In a skid, a driver can lose control of the vehicle.
Defensive drivers avoid most skids by taking reasonable
care suited to existing conditions, and by not overdriving
those conditions. But skids are always possible.
The three types of skids correspond to the vehicle’s
three control systems. In the braking skid, the wheels are
not rolling. In the steering or cornering skid, too much
speed or steering in a curve causes tires to slip and lose
cornering force. And in the acceleration skid, too much
throttle causes the driving wheels to spin.
If the vehicle starts to slide, ease your foot off the
accelerator pedal and quickly steer the way you want
the vehicle to go. If you start steering quickly enough,
the vehicle may straighten out. Always be ready for
a second skid if it occurs.Of course, traction is reduced when water, snow, ice,
gravel, or other material is on the road. For safety, slow
down and adjust your driving to these conditions. It is
important to slow down on slippery surfaces because
stopping distance is longer and vehicle control more
limited.
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
the 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.
4-14