GMC SIERRA DENALI 2003 Owners Manual

I
Higher Speeds (40 m.p.h./64 km/h and above)
J
At higher speeds the front and rear wheels will turn in
the same direction. This improves stability of the vehicle
during lane changes and sweeping turns.
(4 Wheel Steer tow mode): When towing a trailer
the
4 wheel steer tow mode provides enhanced
stability allowing the trailer to follow the path of the tow
vehicle more closely, especially during lane changes.
In this mode the system operates much like the
4 mode,
but is enhanced for trailer towing. It is recommended
for all types and weights
of trailers.
To engage the
4 wheel steer tow mode, press the 4
Wheel Steer button until the 4 and tow indicators light up
on the instrument panel.
If the tow indicator is flashing
you will have to center the steering wheel by turning it to
the left or right. While in the
4 wheel steer tow mode,
it is possible the steering wheel may be slightly
off
center. For more information, see Towing a Trailer on
page
4-5 I.
4-1 2

Car Washes for
QUADRASTEERTM Equipped Vehicles
Notice: Because your vehicle has a wider rear track
a small number
of older car washes may be too
narrow for your vehicle. Conveyor systems on some
automatic car washes may damage your vehicle.
Only use conveyor system car washes with 13-inch
(33 cm) wide conveyor rails and/or stationary
washes with at least 82 inches (208 cm) between the
rails. Before using the car wash check with the
manager.
13 in. 13 in.
(33 cm) (33 . 1. cm)
Off -Road Recovery
You may find that your right wheels have dropped off
the edge of a road onto the shoulder while you’re
driving.
I ,
If the level of the shoulder is only slightly below the
pavement, recovery should be fairly easy. Ease
off the
accelerator and then,
if there is nothing in the way,
steer
so that your vehicle straddles the edge of
the pavement.
You can turn the steering wheel up to
one-quarter turn until the right front tire contacts
the pavement edge, Then turn your steering wheel to go
straight down the roadway.
4-1 3

Passing
The driver of a vehicle about to pass another on a
two-lane highway waits for just the right moment,
accelerates, moves around the vehicle ahead, then
goes back into the right lane again. A simple maneuver?
Not necessarily! Passing another vehicle on a two-lane
highway is a potentially dangerous move, since the
passing vehicle occupies the same lane as oncoming
traffic for several seconds. A miscalculation, an error in
judgment, or a brief surrender to frustration or anger
can suddenly put the passing driver face to face with the
worst of all traffic accidents
- the head-on collision.
So here are some tips for passing:
“Drive ahead.” Look down the road, to the sides
and to crossroads for situations that might affect
your passing patterns.
If you have any doubt
whatsoever about making a successful pass, wait
for a better time.
Watch for traffic signs, pavement markings and
lines.
If you can see a sign up ahead that might
indicate a turn
or an intersection, delay your pass.
A broken center line usually indicates it’s all
right to pass (providing the road ahead is clear).
Never cross a solid line on your side of the lane or
a double solid line, even
if the road seems empty
of approaching traffic.
Do not get too close to the vehicle you want to
pass while you’re awaiting an opportunity. For
one thing, following too closely reduces your area
of vision, especially
if you’re following a larger
vehicle. Also, you won’t have adequate space
if the
vehicle ahead suddenly slows or stops. Keep
back a reasonable distance.
When it looks like a chance to pass is coming up,
start
to accelerate but stay in the right lane and don’t
get too close. Time your move
so you will be
increasing speed as the time comes to move into the
other lane.
If the way is clear to pass, you will have a
“running start” that more than makes up for the
distance you would lose by dropping back. And
if
something happens to cause you to cancel your
pass, you need only slow down and drop back again
and wait for another opportunity.
If other vehicles are lined up to pass a slow vehicle,
wait your turn. But take care that someone isn’t trying
to pass you as you pull out to pass the slow vehicle.
Remember to glance over your shoulder and check
the blind spot.
4-1 4

a
Check your mirrors, glance over your shoulder and
start your left lane change signal before moving out
of the right lane
to pass. When you are far enough
ahead of the passed vehicle to see its front in your
inside mirror, activate your right lane change signal
and move back into the right lane. (Remember that
if
your right outside mirror is convex, the vehicle you
just passed may seem
to be farther away from you
than it really is.)
Try not to pass more than one vehicle at a time on
two-lane roads. Reconsider before passing the next
vehicle.
Don’t overtake a slowly moving vehicle too rapidly.
Even though the brake lamps are not flashing, it may
be slowing down or starting to turn.
If you’re being passed, make
it easy for the following
driver to get ahead
of you. Perhaps you can ease a
little
to the right.
Loss of Control
Let’s review what driving experts say about what
happens when the three control systems (brakes,
steering and acceleration) don’t have enough friction
where the tires meet the road to do what the driver
has asked.
In any emergency, don’t 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
aren’t 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’ll
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.
4-1 5

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:
e
e
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:
e
e
e
e
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.
0
0
0
0
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