2004 GMC YUKON DENALI brake

When the Stabilitrakžsystem has been turned off you
may still hear system noises as a result of the
brake-traction control coming on.
It is recommended to leave the system on for normal
driving conditions, but it may be necessary to turn
the system off if your vehicle is stuck in sand, mud, ice
or snow, and you want to ªrockº your vehicle to
attempt to free it. It may also be necessary to turn off
the system when driving in extreme off-road conditions
where high wheel spin is required. See
If You Are
Stuck: In Sand, Mud, Ice or Snow on page 4-41.
Traction Control Operation
The traction control system is part of the
Stabilitrakžsystem. Traction control limits wheel spin by
reducing engine power to the wheels (engine speed
management) and by applying brakes to each individual
wheel (brake-traction control) as necessary.
The traction control system is enabled automatically
when you start your vehicle, and it will activate
and display the TRACTION ACTIVE message in the
Driver Information Center (DIC) if it senses that any of
the wheels are spinning or beginning to lose traction
while driving. If you turn off Stabilitrak
ž, only the
brake-traction control portion of traction control will
work. The engine speed management will be disabled.
In this state, engine power is not reduced automatically
and the driven wheels can spin more freely. This
can cause the brake-traction control to activateconstantly. For more information on the traction active
message, see
Driver Information Center (DIC) on
page 3-46.
Notice:If the traction off light comes on due to
heavy braking and/or because the traction control
system has been continuously active, do not
allow the wheel(s) of one axle to spin excessively. If
you do, you may be causing damage to the
transfer case. This could lead to costly repairs not
covered by your warranty.
If the brake-traction control system activates constantly
or if the brakes have heated up due to high speed
braking, the brake-traction control will be disabled and
the TRACTION SYS LIMITED message will be
displayed. In the limited mode, the traction control
system will only use engine traction-control and is limited
in its ability to provide optimal performance since the
system will not utilize brake traction-control to control
slip on the drive wheels. The system will return to normal
after the brakes have cooled. This can take up to two
minutes or longer depending on brake usage.
Notice:If you allow the wheel(s) of one axle to spin
excessively while the traction off, ABS and brake
warning lights and the SERVICE STABILITY
MESSAGE are displayed, you could damage the
transfer case. The repairs would not be covered by
your warranty. Reduce engine power and do not
spin the wheel(s) excessively while these lights and
this message are displayed.
4-10

Speed limit signs near curves warn that you should
adjust your speed. Of course, the posted speeds
are based on good weather and road conditions. Under
less favorable conditions you will want to go slower.
If you need to reduce your speed as you approach
a curve, do it before you enter the curve, while your front
wheels are straight ahead.
Try to adjust your speed so you can ªdriveº through the
curve. Maintain a reasonable, steady speed. Wait to
accelerate until you are out of the curve, and then
accelerate gently into the straightaway.
Steering in Emergencies
There are times when steering can be more effective
than braking. For example, you come over a hill and ®nd
a truck stopped in your lane, or a car suddenly pulls
out from nowhere, or a child darts out from between
parked cars and stops right in front of you. You
can avoid these problems by braking Ð if you can stop
in time. But sometimes you can not; there is not
room. That is the time for evasive action Ð steering
around the problem.
Your vehicle can perform very well in emergencies like
these. First apply your brakes.
See
Braking on page 4-6. It is better to remove as much
speed as you can from a possible collision. Then
steer around the problem, to the left or right depending
on the space available.An emergency like this requires close attention and a
quick decision. If you are holding the steering wheel at
the recommended 9 and 3 o'clock positions, you
can turn it a full 180 degrees very quickly without
removing either hand. But you have to act fast, steer
quickly, and just as quickly straighten the wheel
once you have avoided the object.
The fact that such emergency situations are always
possible is a good reason to practice defensive driving
at all times and wear safety belts properly.
4-12

·Do not get too close to the vehicle you want to
pass while you are awaiting an opportunity. For one
thing, following too closely reduces your area of
vision, especially if you are following a larger
vehicle. Also, you will not 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
do not 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 ªrunning startº 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 is not
trying to pass you as you pull out to pass the slow
vehicle. Remember to glance over your shoulder
and check the blind spot.
·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.
·Do not overtake a slowly moving vehicle too rapidly.
Even though the brake lamps are not ¯ashing, it
may be slowing down or starting to turn.
·If you are being passed, make it easy for the
following driver to get ahead of you. Perhaps
you can ease a little to the right.
4-14

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
ªoverdrivingº 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
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.
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 will 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.
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 Ð such as enough water, ice or packed snow
on the road to make a ªmirrored surfaceº Ð and slow
down when you have any doubt.
Remember: Any anti-lock brake system (ABS) helps
avoid only the braking skid.
4-15

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 ®rm grip on the
steering wheel.
·Get a smooth start up the hill and try to maintain
your speed. Do not use more power than you
need, because you do not 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 ®nd
another route.
{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.
·Ease up on your speed as you approach the top of
the hill.
·Attach a ¯ag 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 are there.
·Use your headlamps even during the day. They
make you 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.
Q:What should I do if my vehicle stalls,
or is about to stall, and I can not 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 is what you
shoulddo:
·Push the brake pedal to stop the vehicle and
keep it from rolling backwards. Also, apply the
parking brake.
4-21

·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 will be able to tell if your wheels are
straight and maneuver as you back down. It is
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 yo
must notdo 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 ªrev-upº the engine and regain
forward momentum. This will not 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 is steep enough to
cause you to roll over if you turn around. If you can
not 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 not 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.
4-22

Driving Downhill
When off-roading takes you downhill, you will want to
consider a number of things:
·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, then try to
keep your vehicle headed straight down, and use a
low gear. This way, engine drag can help your brakes
and they will not have to do all the work. Descend
slowly, keeping your 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.
Q: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 is not too
steep to drive down may be too steep to drive
across. You could roll over if you do not drive
straight down.
·Never go downhill with the transmission in
NEUTRAL (N). This is called ªfree-wheeling.º
Your brakes will have to do all the work and could
overheat and fade.
4-23

Q:Am I likely to stall when going downhill?
A:It is much more likely to happen going uphill. But if
it happens going downhill, here is 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
engine.
·Shift back to a low gear, release the parking brake,
and drive straight down.
·If the engine will not start, get out and get help.
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 tumbleend 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 does not mean you
have to drive it. The last vehicle to try it might
have rolled over.
4-24