GMC YUKON DENALI 2003 Owners Manual

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’s 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’ll want to know
how
to use it properly.
Getting Familiar with Off-Road Driving
It’s a good idea to practice in an area that’s safe and
close
to home before you go into the wilderness.
Off-road driving does require some new and different
driving skills. Here’s 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’ll 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’ll need more distance for braking, especially
since u’re on an [-.7aved surface.
When ; u’re driving R-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’re
driving on or
off the road, you and your
passengers should wear safety belts.
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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.
Surface Obstacles: Unseen or hidden obstacles can
be hazardous. A rock, log, hole, rut or bump can startle
you
if you’re not prepared for them. Often these
obstacles are hidden by grass, bushes, snow or even
the rise and fall of the terrain itself. Here are some
things to consider:
0 Is the path ahead clear?
Will the surface texture change abruptly up ahead?
Does the travel take you uphill or downhill?
(There’s more discussion of these subjects later.)
Will you have to stop suddenly or change direction
quickly? When you drive
over obstacles or rough terrain, keep a
firm grip on the steering wheel. Ruts, troughs or
other surface features can jerk the wheel out of your
hands
if you’re not prepared.
When you drive over bumps, rocks, or other obstacles,
your wheels can leave the ground. If this happens,
even with one or two wheels, you can’t control
the vehicle as well or at all.
Because you will be on an unpaved surface, it’s
especially important to avoid sudden acceleration,
sudden turns or sudden braking.
In a way, off-road driving requires a different kind of
alertness from driving on paved roads and highways.
There are no road signs, posted speed limits or
signal lights. You have to use your own good judgment
about what is safe and what isn’t.
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 reflexes, 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. See Drunken Driving
on page 4-2.
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Driving on Off-Road 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 your vehicle can and can’t
do. There are some hills that simply can’t be driven,
no matter how well built the vehicle.
Ma ~ hills are simply ~- - -Lee, .or any vehicle.
If you drive up them, you will stall. If you drive
down them, you can’t 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, don’t drive the hill.
Approaching a Hill
When you approach a hill, you need to decide if it’s one
of those hills that’s 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 things
to consider as you
approach a hill.
e
e
e
e
e
e
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
won’t have
to make turning maneuvers?
Are there obstructions on the hill that can block
your path (boulders, trees, logs or ruts)?
What’s beyond the hill?
Is there a cliff, an
embankment, a drop-off, a fence? Get out and walk
the hill
if you don’t know. It’s the smart way to
find 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.
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Driving Uphill
Once you decide you can safely drive up the hill, you
need to take some special steps.
Use a low year and get a firm grip on the
steering wheel.
your speed. Don’t use more power than you
need, because you don’t want your wheels to start
spinning or sliding.
Try to drive straight up the hill if at all possible. If
the path twists and turns, you might want to find
another route.
Get a smooth start up the hill and try to maintain
0 Sound the horn as you approach the top of the hill
to let opposing traffic know you’re there.
Use your headlamps even during the day. They
make
you more visible to oncoming traffic.
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.
Ease up on your speed as you approach the top of
the hill.
Attach a flag to the vehicle to make you more
visible to approaching traffic on trails or hills. Driving to the top (crest)
of a hill
a, ,ull 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.
Q: What should I do if my vehicle stalls, or is
about to stall, and
I can’t make it up the hill?
A: If this happens, there are some things you should
do and there are some things you must not do. First, here’s what you
should do:
Push the brake pedal to stop the vehicle and keep
it from rolling backwards.
Also, apply the parking
brake.
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If your engine is still running, shift the transmission
to REVERSE (R), release the parking brake, and
slowly back down the hill as straight as possible in
REVERSE (R).
As you are backing down the hill, put your left hand
on the steering wheel at the
12 o’clock position.
This way, you’ll be able
to tell if your wheels
are straight and maneuver as you back down.
It’s best that you back down the hill with your 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.
Here are some things you
must not do if you stall, or
are about to stall, when going up a hill.
Never attempt to prevent a stall by shifting into
NEUTRAL (N)
to “rev-up” the engine and regain
forward momentum. This won’t work. Your vehicle
will roll backwards very quickly and you could
go out of control. Instead, apply the
regular brake to stop the vehicle.
Then apply the parking brake. Shift to
REVERSE
(R), release the parking brake, and
slowly back straight down.
Never attempt to turn around if you are about to
stall when going up a hill. If the hill is steep
enough to stall your vehicle, it’s steep enough
to
cause you to roll over if you turn around. If you can’t
make it up the hill, you must back straight down
the hill.
Q: Suppose, after stalling, I try to back down
the hill and decide
I just can’t do it. What
should
I do?
A: Set the parking brake, put your transmission in
PARK
(P) and 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.
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Driving Downhill
When off-roading takes you downhill, you’ll want to
consider a number of things:
How steep is the downhill? Will I be able to maintain
vehicle control?
0 What’s the surface like? Smooth? Rough? Slippery?
Hard-packed dirt? Gravel?
Are there hidden surface obstacles? Ruts? Logs?
Boulders?
What’s 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, then try to
keep your vehicle headed straight down, and use a
low gear. This way, engine drag can help your brakes
and they won’t have to do all the work. Descend slowly,
keeping your vehicle under control at all times.
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.
0: Are there some things I should not do when
driving down a hill?
A: Yes! These are important because if you ignore
them you could lose control and have a serious
accident.
When driving downhill, avoid turns that take you
across the incline of the hill. A hill that’s not too
steep to drive down may be too steep to drive across. You could roll over
if you don’t drive
straight down.
Never go downhill with the transmission in
NEUTRAL (N). This is called “free-wheeling.”
Your brakes will have to
do all the work and could
overheat and fade.
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Q: Am I likely to stall when going downhill?
A: It’s much more likely to happen going uphill. But if it
happens going downhill, here’s what
to do.
Stop your vehicle by applying the regular brakes.
Apply the parking brake.
Shift to PARK (P) and, while still braking, restart the
Shift back to a low gear, release the parking brake,
If the engine won’t start, get out and get help.
engine.
and
drive straight down.
Driving Across an Incline
Sooner or later, an off-road trail will probably go across
the incline
of a hill. If this happens, you have to
decide whether
to try to drive across the incline. Here
are some things
to consider:
A hill that can be driven straight up or down may be
too steep to drive across. When you go straight up
or down a
hill, the length of the wheel base (the
distance from the front wheels
to the rear wheels)
reduces the likelihood the vehicle will tumble end
over end. But when you drive across an incline,
the much more narrow track width (the distance
between the left and right wheels) may not prevent
the vehicle from tilting and rolling over.
Also,
driving across an incline puts more weight on the
downhill wheels. This could cause a downhill
slide or a rollover.
Surface conditions can be a problem when you
drive across a hill.
Loose gravel, muddy spots,
or even wet grass can cause your tires
to slip
sideways, downhill.
If the vehicle slips sideways,
it can hit something that will trip
it (a rock, a rut, etc.)
and roll over.
Hidden obstacles can make the steepness of the
incline even worse. If you drive across a rock
with the uphill wheels, or
if the downhill wheels
drop into a rut or depression, your vehicle can tilt
even more.
For reasons like these, you need to decide carefully
whether to try to drive across an incline. Just because
the trail goes across the incline doesn’t mean you
have to drive it. The last vehicle to try it might have
rolled over.
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,.iving across an -_:line that’s too steep wili
make your vehicle roll over. You could be
seriously injured
or killed. If you have any
doubt about the steepness
of the incline, don’t
drive across
it. Find another route instead.
Q: What if I’m driving across an incline that’s not
too steep, but
I hit some loose gravel and start
to slide downhill. What should
I do?
A: If you feel your vehicle starting to slide sideways,
turn downhill. This should help straighten out the
vehicle and prevent the side slipping. However,
a much better way to prevent this is to get
out and
“walk the course”
so you know what the surface
is like before you drive it.
Stalling on an Incline
If your vehicle stalls when you’re crossing an incline, be
sure
you (and your 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’ll 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.
4-25

L

Driving in Water
Heavy rain can mean flash flooding, and flood waters
demand extreme caution.
Find out how deep the water
is before you drive through
it. If it’s deep enough to cover your wheel hubs, axles
or exhaust pipe, don’t try
it - you probably won’t
get through. Also, water that deep can damage your
axle and other vehicle parts.
If the water isn’t 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’ll 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.
I
- - - - -ng through rushing water can be
dangerous. Deep water can sweep your vehicle
downstream and you and your passengers
i could drown. If it’s only shallow water, it can
still wash away the ground from under your
tires, and you could lose traction and roll the
vehicle over. Don’t drive through rushing water.
I I
See Driving in Rain and on Wet Roads on page 4-29 for
more information on driving through water.
After Off-Road Driving
Remove any brush or debris that has collected on the
underbody, chassis or under the hood. These
accumulations can be a fire hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires and exhaust
system for damage.
Also, check the fuel lines and
cooling system for any leakage.
Your vehicle will require more frequent service due to
off-road use. Refer
to the Maintenance Schedule
for additional information.
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