2003 GMC SIERRA DENALI Owners Manual

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.
Operating Your All-Wheel-Drive
Vehicle
Off Paved Roads
Many of the same design features that help make your
vehicle responsive on paved roads during poor
weather conditions
- features like the locking rear axle
and all-wheel drive
- help make it much better
suited for off-road use than a conventional passenger
car. Its higher ground clearance also helps your vehicle
step over some off-road obstacles. But your vehicle
doesn’t have features like special underbody shielding
and a transfer case low gear range, things that are
usually thought necessary for extended or sever off-road
service. This guide
is for operating your vehicle off
paved roads.
Also, see Braking on page 4-6.
Off-road driving can be great fun. But it does have
some definite hazards. The greatest of these is
the terrain itself.
“Off-roading” means you’ve left the great North American\
road system behind. Traffic lanes aren’t marked.
Curves aren’t banked. There are no road signs.
Surfaces can be slippery, rough, uphill or downhill. In
short, you’ve gone right back to nature.
Off-road driving involves some new skills. And that’s
why it’s very important that
you read this guide.
You’ll find many driving tips and suggestions. These will
help make your off-road driving safer and more
enjoyable.
Before You Go Off-Roading
There are some things to do before you go out. For
example, be sure to have all necessary maintenance
and service work done. Check to make sure all
underbody shields (if
so equipped) are properly
attached.
Is there enough fuel? Is the spare tire fully
inflated? Are the fluid levels up where they should be?
What are the local laws that apply to off-roading
where you’ll be driving?
If you don’t know, you should
check with law enforcement people in the area. Will you
be on someone’s private land? If
so, be sure to get
the necessary permission.
4-1 6

Loading Your Vehicle for Off-Road Driving
There are some important things to remember about
how to lad your vehicle.
The heaviest things should be on the load floor and
forward
of your rear axle. Put heavier items as far
forward as you can.
Be sure the load is secured properly, so driving 011
the off-ro? ‘I doesn’t toss things around. +----.
0 Cargo on the load floor piled higher than
the seatbacks can be thrown forward
during a sudden stop. You or your passengers could be injured. Keep cargo
below the top of the seatbacks.
CAUTION: (Continued)
0 Unsecured cargo on the load floor can be
tossed about when driving over rough
terrain. You or your passengers can be struck by flying objects. Secure the cargo
properly.
Heavy loads on the roof raise the vehicle’s
center of gravity, making
it more likely to
roll over. You can be seriously or fatally
injured if the vehicle
rolls over. Put heavy
loads inside
the cargo area, not on the roof.
Keep cargo
in the cargo area as far forward
and low as possible.
You’ll find other important information in this manual.
See
Loading Your Vehicle on page 4-45 and Tires
on page 5-6 1.
4-1 7

Environmental Concerns
Off-road driving can provide wholesome and satisfying
recreation. However, it also raises environmental
concerns. We recognize these concerns and urge every
off-roader to follow these basic rules for protecting
the environment:
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Always use established trails, roads and areas that
have been specially set aside for public off-road
recreational driving; obey all posted regulations.
Avoid any driving practice that could damage the
environment
- shrubs, flowers, trees, grasses - or
disturb wildlife (this includes wheel-spinning,
breaking down trees or unnecessary driving through
streams or over soft ground.
Always carry a litter bag
... make sure all refuse is
removed from any campsite before leaving.
Take extreme care with open fires (where permitted),
camp stoves and lanterns.
Never park your vehicle over dry grass or other
combustible materials that could catch fire from the
heat of the vehicle’s exhaust system.
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 on 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.
4-1 8

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. Heres’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 vehicles
is to control your speed. Here are some things to keep in
mind. At higher speeds:
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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 you’re on an unpaved surface. When you’re 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’re
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.
4-1 9

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:
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, toughs 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.
4-20

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.
Many hills are si )ly too steep for 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 ills 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 tip, 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.
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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 dimply too rough? Steep hills often have
ruts, gullies, troughs, and exposed rocks because
they are more susceptible to the effects of erosion.
4-2 1

Driving Uphill
Once you decide you can safely drive up the hill, you
need to take some special steps.
Use a low gear and get a firm grip on the steering
wheel.
0 Get a smooth start up the hill and try to maintain
your speed. Don’t use more power than yo 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.
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Ease up on your speed as you approach the tip of
the hill.
Attach a flag to the vehicle to make you 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’re there.
Use your headlamps even during the day. They
make you more visible
~ 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.
A CAUTION: 0
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.
4-22

Q: What should I do if my vehicle stalls, or is
A: if this happens, there are some things you should
about to stall, and
I can’t
make it up the hill?
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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
if from rolling backwards. Also, apply the parking
brake.
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 our wheels
straight rather than in the left or tight 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.
9 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.
9 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.
4-23