engine HUMMER H3 2009 Service Manual

Driving Your
Vehicle
Your Driving, the Road,
and the Vehicle
Driving for Better Fuel
Economy...........................4-1
Defensive Driving................4-2
Drunk Driving.....................4-2
Control of a Vehicle............4-3
Braking...............................4-3
Antilock Brake
System (ABS)...................4-5
Braking in Emergencies......4-6
StabiliTrak®System............4-6
Traction Control
System (TCS)...................4-7
Locking Rear Axle..............4-8
Locking Front Axle..............4-9
Steering............................4-10
Off-Road Recovery............4-11
Passing.............................4-12
Loss of Control.................4-12
Off-Road Driving...............4-13
Assist Steps......................4-28
Driving at Night.................4-28
Driving in Rain and on
Wet Roads......................4-29
Before Leaving on a
Long Trip........................4-30
Highway Hypnosis.............4-30
Hill and Mountain Roads. . .4-30
Winter Driving...................4-31
If Your Vehicle is
Stuck in Sand, Mud,
Ice, or Snow
...................4-33
Rocking Your Vehicle to
Get It Out.......................4-34
Recovery Loops................4-34
Loading the Vehicle..........4-35
Truck-Camper Loading
Information......................4-39
Towing
Towing Your Vehicle.........4-40
Recreational Vehicle
Towing............................4-40
Towing a Trailer................4-42
Trailer
Recommendations...........4-53
Your Driving, the
Road, and the Vehicle
Driving for Better Fuel
Economy
Driving habits can affect fuel
mileage. Here are some driving tips
to get the best fuel economy
possible.
Avoid fast starts and accelerate
smoothly.
Brake gradually and avoid abrupt
stops.
Avoid idling the engine for long
periods of time.
When road and weather
conditions are appropriate, use
cruise control, if equipped.
Always follow posted speed limits
or drive more slowly when
conditions require.
Keep vehicle tires properly
inated.
Driving Your Vehicle 4-1

Antilock Brake
System (ABS)
This vehicle has the Antilock Brake
System (ABS), an advanced
electronic braking system that will
help 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 ABS, this
warning light stays on. See
Antilock Brake System (ABS)
Warning Light on page 3-28.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 wheel.
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.
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.
Driving Your Vehicle 4-5

automatically disabled. See
Full-Time Four-Wheel Drive on
page 2-24for more information. 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 it is
necessary to “rock” the vehicle to
attempt to free it. SeeIf Your
Vehicle is Stuck in Sand, Mud, Ice,
or Snow on page 4-33.
To turn the system off, press and
hold the TCS/StabiliTrak button until
the traction off light comes on.
This light comes on steady when
TCS has been turned off. This light
ashes when StabiliTrak is active.To Turn off TCS and StabiliTrak,
press and hold the TCS/StabiliTrak
button until the STAB SYS OFF
message displays on the DIC. Press
and release the TCS/StabiliTrak
button again to turn StabiliTrak
back on. See “Traction Control
System (TCS)”, following, for more
information on turning TCS off
and on.
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 reduces
engine power. 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.TCS can operate on dry roads
under some conditions. When this
happens, the system may be
heard 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 3-9for more information.
TRACTION FAULT appears on
the Driver information Center (DIC)
when a TCS or antilock brake
system problem has been detected
and the vehicle needs service.
When this message is on, the
system will not limit wheel spin.
Driving Your Vehicle 4-7

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

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

For very large dips, ditches or
small washes, coast in, using the
engine as a brake (transmission
and transfer case lowest gears).
Then, use the low ranges in
the transmission and transfer case
to power out.
Roll The Tires Over Large Rocks
Do not straddle large rocks; drive
over them, letting the tire cover
the rock. The tread of the tire
is thicker and tougher than the
sidewall of the tire and is more
resilient to impact than underbody
components.Log Crossing
Using the proper technique, the
vehicle will cross logs up to
10 inches (25.4 cm) in diameter.
Approach the log at approximately a
15° angle (A) with the transmission
in 1 (First) and the transfer case
in Four-Wheel-Low Lock and “walk”
the vehicle over, one tire at a
time. It may be necessary to
modulate the brake pedal and
accelerator to avoid spin-out. Ease
the vehicle down from the log
with the brake.Driving on Hills
Off-road driving often takes you up,
down, or across a hill. Driving
safely on hills requires good
judgment and an understanding of
what the vehicle can and cannot do.
There are some hills that simply
cannot be driven, no matter how well
built the vehicle.
{CAUTION
Many hills are simply too steep for
any vehicle. If you drive up them,
you will stall. If you drive down
them, you cannot control your
speed. If you drive across them,
you will roll over. You could be
seriously injured or killed. If you
have any doubt about the
steepness, do not drive the hill.
4-20 Driving Your Vehicle

Do not continue if the vehicle
shudders or exhibits suspension
hopping. This can cause
damage to the driveline or
suspension components.
Improper driving technique is not
covered by the vehicle warranty.
{CAUTION
Turning or driving across steep
hills can be dangerous. You could
lose traction, slide sideways, and
possibly roll over. You could be
seriously injured or killed. When
driving up hills, always try to go
straight up.
Try to drive straight up the hill if
at all possible. If the path twists
and turns, you might want to
nd another route.
Ease up on the speed as you
approach the top of the hill.
Attach a ag to the vehicle to be
more visible to approaching
traffic on trails or hills.
Sound the horn as you approach
the top of the hill to let opposing
traffic know you are there.
Use headlamps even during the
day to make the vehicle more
visible to oncoming traffic.
{CAUTION
Driving to the top (crest) of a hill
at full speed can cause an
accident. There could be a
drop-off, embankment, cliff, or
even another vehicle. You could
be seriously injured or killed. As
you near the top of a hill, slow
down and stay alert.If the vehicle stalls, or is about to
stall, and you cannot make it up
the hill:
Push the brake pedal to stop the
vehicle and keep it from rolling
backwards and apply the parking
brake.
If the engine is still running, shift
the transmission to R (Reverse),
release the parking brake,
and slowly back down the hill in
R (Reverse).
If the engine has stopped
running, you need to restart
it. With the brake pedal
pressed, apply the parking
brake. If the vehicle has an
automatic transmission, shift the
transmission to P (Park).
Restart the engine. Then, shift to
R (Reverse), release the
parking brake, and slowly back
down the hill as straight as
possible in R (Reverse).
4-22 Driving Your Vehicle

While backing down the hill, put
your left hand on the steering
wheel at the 12 o’clock position
so you can tell if the wheels
are straight and can maneuver
as you back down. It is best
to back down the hill with
the wheels straight rather than
in the left or right direction.
Turning the wheel too far to the
left or right will increase the
possibility of a rollover.
Things not to do if the vehicle stalls,
or is about to stall, when going
up a hill:
Never attempt to prevent a stall
by shifting into N (Neutral) to
rev-up the engine and regain
forward momentum. This will
not work. The vehicle can
roll backward very quickly and
could go out of control.
Never try to turn around if about
to stall when going up a hill. If
the hill is steep enough to
stall the vehicle, it is steep
enough to cause it to roll over. If
you cannot make it up the hill,
back straight down the hill.
If, after stalling, you try to back
down the hill and decide you just
cannot do it, set the parking brake.
If the vehicle has an automatic
transmission, shift to P (Park). Turn
off the engine. Leave the vehicle
and go get some help. Exit on
the uphill side and stay clear of the
path the vehicle would take if it
rolled downhill. Do not shift
the transfer case to Neutral when
you leave the vehicle. Leave it
in some gear.{CAUTION
Shifting the transfer case to
Neutral can cause your vehicle to
roll even if the transmission is in
P (Park). This is because the
Neutral position on the transfer
case overrides the transmission.
You or someone else could be
injured. If you are going to leave
your vehicle, set the parking
brake and shift the transmission
to P (Park). But do not shift the
transfer case to Neutral.
Driving Your Vehicle 4-23

Driving Downhill
When off-roading takes you
downhill, consider:
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, try to keep the vehicle
headed straight down. Use a low
gear so engine drag can help
the brakes so they do not have to
do all the work. Descend slowly,
keeping the 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.
Things not to do when driving down
a hill:
When driving downhill, avoid
turns that take you across
the incline of the hill. A hill that
is not too steep to drive down
might be too steep to drive
across. The vehicle could
roll over.
Never go downhill with the
transmission in N (Neutral), called
free-wheeling. The brakes will
have to do all the work and could
overheat and fade.Vehicles are much more likely to
stall when going uphill, but if it
happens when going downhill:
1. Stop the vehicle by applying the
regular brakes and apply the
parking brake.
2. With an automatic transmission,
shift to P (Park). 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.
4-24 Driving Your Vehicle