traction control HUMMER H2 2006 User Guide

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.
The Traction Control System 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 doesn’t 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. See
Cruise Control on page 3-11.
Another feature of this system is the Traction
Control 2 (TC2) mode. TC2 should be selected for
improved traction and system performance when the
vehicle is on loose surfaces such as deep sand or mud.To enter this mode,
press the TC2 button
located on the instrument
panel to the right of
the steering wheel.
TC2 only operates in the following transfer case modes:
Four-Wheel-High Lock
Four-Wheel-Low Lock
Four-Wheel-Low Lock and Rear Axle Lock
SeeLocking Rear Axle on page 4-10for more
information on the rear axle lock.
It will not operate in Four-Wheel-High. If the TC2 button
is pressed while in Four-Wheel High, the light will
ash for about 15 seconds and then go out. The light
should also come on briey when you turn the ignition
key to RUN; if it doesn’t see your dealer for service.
4-9

If you restart your engine, the system reverts to the
standard TCS mode.
The traction off light will
come on when a Traction
Control System or
Anti-Lock Brake System
problem has been detected
and the vehicle needs
service.
SeeTraction Off Light on page 3-36.
When the traction off light is on, adjust your driving
accordingly.
The traction control system, as delivered from the
factory, will automatically come on whenever you start
your vehicle.
Adding non-GM accessories can affect your vehicle’s
performance. SeeAccessories and Modications
on page 5-3for more information.Locking Rear Axle
The locking rear axle can give your 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 above the transfer
case buttons to the
right of the steering wheel.
To lock the rear axle, do the following:
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 2-30for 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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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 20 mph (32 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. If you need four-wheel drive when
traveling on pavement, use only 4HI.
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.
Steering Tips
It is important to take curves at a reasonable speed.
A lot of the “driver lost control” accidents mentioned on
the news happen on curves. Here is why:
Experienced driver or beginner, each of us is subject to
the same laws of physics when driving on curves.
The traction of the tires against the road surface makes
it possible for the vehicle to change its path when
you turn the front wheels. If there is no traction, inertia
will keep the vehicle going in the same direction. If
you have ever tried to steer a vehicle on wet ice, you
will understand this.
The traction you can get in a curve depends on the
condition of your tires and the road surface, the angle at
which the curve is banked, and your speed. While
you are in a curve, speed is the one factor you
can control.
Suppose you are steering through a sharp curve.
Then you suddenly accelerate. Both control
systems — steering and acceleration — have to do
their work where the tires meet the road. Adding
the sudden acceleration can demand too much of
those places. You can lose control. SeeTraction
Control System (TCS) on page 4-9.
What should you do if this ever happens? Ease up on
the accelerator pedal, steer the vehicle the way you
want it to go, and slow down.
4-11

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.
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 your vehicle’s
three control systems. In the braking skid, your 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.
A cornering skid is best handled by easing your foot off
the accelerator pedal.If your 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,
your 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, you
will want to slow down and adjust your driving to
these conditions. It is important to slow down on slippery
surfaces because stopping distance will be 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 engine braking by shifting to a
lower gear. Any sudden changes could cause the tires
to slide. You may 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 Anti-Lock Brake System (ABS) helps
avoid only the braking skid.
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 will not operate if the brakes
are applied, even slightly.
4. If wheel spin cannot be controlled by the system,
fully press the brake pedal with your left foot so all
wheel spin is halted.
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.
4-21

Getting Familiar with Off-Road Driving
It is a good idea to practice in an area that is safe
and close to home before you go into the wilderness.
Off-road driving does require some new and different
skills. Here is what we mean.
Tune your senses to different kinds of signals. Your
eyes, for example, need to constantly sweep the terrain
for unexpected obstacles. Your ears need to listen
for unusual tire or engine sounds. With your arms,
hands, feet and body, you will need to respond to
vibrations and vehicle bounce.
Controlling your vehicle is the key to successful off-road
driving. One of the best ways to control your vehicle
is to control your speed. Here are some things to keep
in mind. At higher speeds:
You approach things faster and you have less time
to scan the terrain for obstacles.
You have less time to react.
You have more vehicle bounce when you drive
over obstacles.
You will need more distance for braking, especially
since you are on an unpaved surface.
{CAUTION:
When you are driving off-road, bouncing and
quick changes in direction can easily throw
you out of position. This could cause you to
lose control and crash. So, whether you are
driving on or off the road, you and your
passengers should wear safety belts.
Scanning the Terrain
Off-road driving can take you over many different kinds
of terrain. You need to be familiar with the terrain
and its many different features. Here are some things
to consider.
Surface Conditions:Off-roading can take you over
hard-packed dirt, gravel, rocks, grass, sand, mud, snow,
or ice. Each of these surfaces affects the steering,
acceleration, and braking of your vehicle in different
ways. Depending upon the kind of surface you are on,
you may experience slipping, sliding, wheel spinning,
delayed acceleration, poor traction, and longer
braking distances.
4-22

Approaching a Hill
When you approach a hill, you need to decide if it is
one of those hills that is just too steep to climb, descend,
or cross. Steepness can be hard to judge. On a very
small hill, for example, there may be a smooth, constant
incline with only a small change in elevation where
you can easily see all the way to the top. On a large hill,
the incline may get steeper as you near the top, but
you may not see this because the crest of the hill
is hidden by bushes, grass, or shrubs.
Here are some other things to consider as you approach
a hill:
Is there a constant incline, or does the hill get
sharply steeper in places?
Is there good traction on the hillside, or will the
surface cause tire slipping?
Is there a straight path up or down the hill so you
will not have to make turning maneuvers?
Are there obstructions on the hill that can block your
path, such as boulders, trees, logs, or ruts?
What is beyond the hill? Is there a cliff, an
embankment, a drop-off, a fence? Get out and
walk the hill if you do not know. It is the smart way
to nd out.
Is the hill simply too rough? Steep hills often have
ruts, gullies, troughs and exposed rocks because
they are more susceptible to the effects of erosion.
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 your 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.
4-26

Hard packed snow and ice offer the worst tire traction.
On these surfaces, it is very easy to lose control.
On wet ice, for example, the traction is so poor that you
will have difficulty accelerating. And if you do get
moving, poor steering and difficult braking can cause
you to slide out of control.
{CAUTION:
Driving on frozen lakes, ponds, or rivers can
be dangerous. Underwater springs, currents
under the ice, or sudden thaws can weaken the
ice. Your vehicle could fall through the ice and
you and your passengers could drown. Drive
your vehicle on safe surfaces only.
Driving in Water
Heavy rain can mean ash ooding, and ood waters
demand extreme caution.
Find out how deep the water is before you drive through
it. If it is deep enough to cover your wheel hubs, axles, or
exhaust pipe, do not try it — you probably will not get
through. Also, water that deep can damage your axle and
other vehicle parts. Your vehicle is capable of depths up
to 20 inches. Know how to judge whether the water is
deeper than this before proceeding into it.If the water is not too deep, drive slowly through it. At
faster speeds, water splashes on your ignition
system and your vehicle can stall. Stalling can also
occur if you get your tailpipe under water. And, as long
as your tailpipe is under water, you will never be
able to start your engine. When you go through water,
remember that when your brakes get wet, it may
take you longer to stop.
{CAUTION:
Driving through rushing water can be
dangerous. Deep water can sweep your
vehicle downstream and you and your
passengers could drown. If it is only shallow
water, it can still wash away the ground from
under your tires, and you could lose traction
and roll the vehicle over. Do not drive through
rushing water.
SeeDriving in Rain and on Wet Roads on page 4-39for
more information on driving through water.
4-33

Driving in Rain and on Wet Roads
Rain and wet roads can mean driving trouble. On a wet
road, you cannot stop, accelerate, or turn as well
because your tire-to-road traction is not as good as on
dry roads. And, if your tires do not have much tread
left, you will get even less traction. It is always wise to
go slower and be cautious if rain starts to fall while
you are driving. The surface may get wet suddenly when
your reexes are tuned for driving on dry pavement.The heavier the rain, the harder it is to see. Even if your
windshield wiper blades are in good shape, a heavy
rain can make it harder to see road signs and
traffic signals, pavement markings, the edge of the road,
and even people walking.
It is wise to keep your wiping equipment in good shape
and keep your windshield washer uid reservoir lled
with washer uid. Replace your windshield wiper inserts
when they show signs of streaking or missing areas
on the windshield, or when strips of rubber start
to separate from the inserts.
{CAUTION:
Wet brakes can cause accidents. They will not
work as well in a quick stop and may cause
pulling to one side. You could lose control of
the vehicle.
After driving through a large puddle of water
or a car wash, apply your brake pedal lightly
until your brakes work normally.
Driving too fast through large water puddles or even
going through some car washes can cause problems,
too. The water may affect your brakes. Try to avoid
puddles. But if you cannot, try to slow down before you
hit them.
4-39

What is the worst time for this? Wet ice. Very cold snow
or ice can be slick and hard to drive on. But wet ice
can be even more trouble because it may offer the least
traction of all. You can get wet ice when it is about
freezing, 32°F (0°C), and freezing rain begins to fall. Try
to avoid driving on wet ice until salt and sand crews
can get there.
Whatever the condition — smooth ice, packed, blowing,
or loose snow — drive with caution.
The Traction Control System (TCS) improves your
ability to accelerate when driving on a slippery road. If
you are driving in deep snow, turn your TCS to the TC2mode. It will improve your ability to accelerate. SeeIf
Your Vehicle is Stuck in Sand, Mud, Ice or Snow
on page 4-50. Even though your vehicle has TCS, you
will want to slow down and adjust your driving to
the road conditions. Under certain conditions, you may
want to turn the TCS off, such as when driving
through deep snow and loose gravel, to help maintain
vehicle motion at lower speeds. SeeTraction Control
System (TCS) on page 4-9.
Your Anti-Lock Brake System (ABS) improve your
vehicle’s stability when you make a hard stop on a
slippery road. Even though you have ABS, you will want
to begin stopping sooner than you would on dry
pavement. SeeAnti-Lock Brake System (ABS) on
page 4-7.
Allow greater following distance on any slippery road.
Watch for slippery spots. The road might be ne until
you hit a spot that is covered with ice. On an
otherwise clear road, ice patches may appear in
shaded areas where the sun cannot reach, such as
around clumps of trees, behind buildings, or under
bridges. Sometimes the surface of a curve or an
overpass may remain icy when the surrounding
roads are clear. If you see a patch of ice ahead of
you, brake before you are on it. Try not to brake while
you are actually on the ice, and avoid sudden
steering maneuvers.
4-47