traction control HUMMER H3 2009 User Guide

5. Wait for the light in the button
to stop ashing and remain
illuminated to show that the front
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.
Locking axles will be disengaged
when the wheel 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
4LO 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.
4-10 Driving Your Vehicle

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.
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.
Remember: Any traction control
system helps avoid only the
acceleration skid. If the traction
system is off, then an acceleration
skid is best handled by easing
your foot off the accelerator pedal.
SeeTraction Control System
(TCS) on page 4-7andStabiliTrak
®
System on page 4-6.
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.
4-12 Driving Your Vehicle

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 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 reducing
vehicle speed by shifting to a lower
gear. Any sudden changes could
cause the tires to slide. You may 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.Off-Road Driving
The airbag system is designed to
work properly under a wide range
of conditions, including off-road
usage. Always wear your safety belt
and observe safe driving speeds,
especially on rough terrain.
Drinking and driving can be very
dangerous on any road and this is
certainly true for off-road driving.
At the very time you need special
alertness and driving skills, your
reexes, perceptions, and judgment
can be affected by even a small
amount of alcohol. You could
have a serious — or even
fatal — accident if you drink and
drive or ride with a driver who has
been drinking.Off-roading can be great fun
but has some denite hazards. The
greatest of these is the terrain
itself. When off-road driving, traffic
lanes are not marked, curves are not
banked, and there are no road
signs. Surfaces can be slippery,
rough, uphill, or downhill.
Avoid sharp turns and abrupt
maneuvers. Failure to operate the
vehicle correctly off-road could result
in loss of vehicle control or vehicle
rollover.
Off-roading involves some new
skills. That is why it is very important
that you read these driving tips
and suggestions to help make
off-road driving safer and more
enjoyable.
Driving Your Vehicle 4-13

The vehicle should be able to
traverse a 40% (22 degrees) side
slope at 6 mph (9.7 km/h) while fully
loaded on high friction surfaces.The vehicle can climb a
16 inch (40.6 cm) vertical step.
Step climbing is best done by
approaching the step at an angle
rather than straight on.
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 1 (First) gear,
Four-Wheel-Low 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.
Driving Your Vehicle 4-17

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: Four-Wheel
High position for higher speeds
and Four-Wheel-Low Lock
for more torque and lower
speeds. Transmission 1 (First)
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.
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-roading requires some new
and different skills.
Tune your senses to different
kinds of signals. Your eyes need
to constantly sweep the terrain
for unexpected obstacles. Your ears
need to listen for unusual tire or
engine sounds. Use your arms,
hands, feet, and body to respond to
vibrations and vehicle bounce.Controlling the vehicle is the key to
successful off-road driving. One of
the best ways to control the
vehicle is to control the speed.
At higher speeds:
You approach things faster and
have less time to react.
There is less time to scan the
terrain for obstacles.
The vehicle has more bounce
when driving over obstacles.
More braking distance is needed,
especially 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.
4-18 Driving Your Vehicle

Scanning the Terrain
Off-road driving can take you over
many different kinds of terrain.
Be familiar with the terrain and its
many different features.
Surface Conditions:Off-roading
surfaces can be hard-packed
dirt, gravel, rocks, grass, sand,
mud, snow, or ice. Each of these
surfaces affects the vehicle’s
steering, acceleration, and braking
in different ways. Depending on
the surface, slipping, sliding, wheel
spinning, delayed acceleration,
poor traction, and longer braking
distances can occur.
Surface Obstacles:Unseen or
hidden obstacles can be hazardous.
A rock, log, hole, rut, or bump
can startle you if you are not
prepared for them. Often these
obstacles are hidden by grass,
bushes, snow, or even the rise and
fall of the terrain itself.Some things to consider:Is the path ahead clear?
Will the surface texture change
abruptly up ahead?
Does the travel take you uphill or
downhill?
Will you have to stop suddenly or
change direction quickly?
When driving over obstacles or
rough terrain, keep a rm grip on the
steering wheel. Ruts, troughs, or
other surface features can jerk the
wheel out of your hands.
When driving over bumps, rocks, or
other obstacles, the wheels can
leave the ground. If this happens,
even with one or two wheels,
you cannot control the vehicle as
well or at all.
Because you will be on an unpaved
surface, it is especially important
to avoid sudden acceleration,
sudden turns, or sudden braking.Off-roading requires a different
kind of alertness from driving on
paved roads and highways. There
are no road signs, posted speed
limits, or signal lights. Use
good judgment about what is safe
and what is not.Crossing Obstacles
Approach Angle — a Key to
Mobility
If you encounter a large dip in the
terrain, do not enter straight on;
enter at an angle — 15° minimum
approach (A), 75° maximum
approach angle (B).
Driving Your Vehicle 4-19

Approaching a Hill
When you approach a hill, decide
if it is 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 might not see this
because the crest of the hill
is hidden by bushes, grass, or
shrubs.
Consider this 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.
See “Hill Start Assist” underBraking
on page 4-3for information on
vehicles stopped on a grade.
Driving Uphill
Once you decide it is safe to drive
up the hill:
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 speed.
Not using more power than
needed can avoid spinning the
wheels 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.
Driving Your Vehicle 4-21

Stalling on an Incline
{CAUTION
Getting out on the downhill (low)
side of a vehicle stopped across
an incline is dangerous. If the
vehicle rolls over, you could be
crushed or killed. Always get out
on the uphill (high) side of the
vehicle and stay well clear of the
rollover path.
If the vehicle stalls when crossing
an incline, be sure you, and
any passengers, get out on the
uphill side, even if the door there is
harder to open. If you get out on
the downhill side and the vehicle
starts to roll over, you will be right in
its path.
If you have to walk down the slope,
stay out of the path the vehicle
will take if it does roll over.
Driving in Mud, Sand, Snow,
or Ice
When you drive in mud, snow, or
sand, the wheels do not get good
traction. Acceleration is not as quick,
turning is more difficult, and braking
distances are longer.
It is best to use a low gear when in
mud — the deeper the mud, the
lower the gear. In really deep mud,
keep the vehicle moving so it
does not get stuck.
When driving on sand, wheel
traction changes. On loosely packed
sand, such as on beaches or
sand dunes, the tires will tend to
sink into the sand. This affects
steering, accelerating, and braking.
Drive at a reduced speed and
avoid sharp turns or abrupt
maneuvers.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 the vehicle does
get moving, poor steering and
difficult braking can cause it 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.
4-26 Driving Your Vehicle

Driving in Rain and on
Wet Roads
Rain and wet roads can reduce
vehicle traction and affect your
ability to stop and accelerate.
Always drive slower in these types
of driving conditions and avoid
driving through large puddles and
deep-standing or owing water.
{CAUTION
Wet brakes can cause crashes.
They might not work as well in a
quick stop and could cause
pulling to one side. You could
lose control of the vehicle.
After driving through a large
puddle of water or a car/vehicle
wash, lightly apply the brake
pedal until the brakes work
normally.
(Continued)
CAUTION (Continued)
Flowing or rushing water creates
strong forces. Driving through
owing water could cause your
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be
very cautious about trying to drive
through owing water.
Hydroplaning
Hydroplaning is dangerous. Water
can build up under your vehicle’s
tires so they actually ride on
the water. This can happen if the
road is wet enough and you
are going fast enough. When your
vehicle is hydroplaning, it has little or
no contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is
to slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet
weather driving tips include:
Allow extra following distance.
Pass with caution.
Keep windshield wiping
equipment in good shape.
Keep the windshield washer uid
reservoir lled.
Have good tires with proper tread
depth. SeeTires on page 5-44.
Turn off cruise control.
Driving Your Vehicle 4-29

{CAUTION
Coasting downhill in N (Neutral)
or with the ignition off is
dangerous. The brakes will have
to do all the work of slowing down
and they could get so hot that
they would not work well. You
would then have poor braking or
even none going down a hill. You
could crash. Always have the
engine running and the vehicle in
gear when going downhill.
Stay in your own lane. Do not
swing wide or cut across the
center of the road. Drive at
speeds that let you stay in your
own lane.
Top of hills: Be alert — something
could be in your lane (stalled car,
accident).
Pay attention to special road
signs (falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.
SeeOff-Road Driving on page 4-13
for information about driving
off-road.
Winter Driving
Driving on Snow or Ice
Drive carefully when there is snow
or ice between the tires and the
road, creating less traction or grip.
Wet ice can occur at about 32°F
(0°C) when freezing rain begins to
fall, resulting in even less traction.
Avoid driving on wet ice or in
freezing rain until roads can be
treated with salt or sand.
Drive with caution, whatever the
condition. Accelerate gently
so traction is not lost. Accelerating
too quickly causes the wheelsto spin and makes the surface
under the tires slick, so there is even
less traction.
Try not to break the fragile traction. If
you accelerate too fast, the drive
wheels will spin and polish the
surface under the tires even more.
TheTraction Control System (TCS)
on page 4-7improves the ability
to accelerate on slippery roads, but
slow down and adjust your driving
to the road conditions. When driving
through deep snow, turn off the
traction control system to help
maintain vehicle motion at lower
speeds.
TheAntilock Brake System (ABS)
on page 4-5improves vehicle
stability during hard stops on a
slippery roads, but apply the brakes
sooner than when on dry pavement.
Driving Your Vehicle 4-31