2004 GMC YUKON XL DENALI traction control

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 are 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 is 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
®rm grip on the steering wheel. Ruts, troughs or
other surface features can jerk the wheel out of your
hands if you are 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 not control the
vehicle as well or at all.
Because you will be on an unpaved surface, it is
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 is not.
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 re¯exes, perceptions and judgment can be
affected by even a small amount of alcohol. You
could have a serious Ð or even fatal Ð accident if you
drink and drive or ride with a driver who has been
drinking. See
Drunken Driving on page 4-2.
4-19

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
not do. There are some hills that simply can not 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 can not 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.
Approaching a Hill
When you approach a hill, you need to decide if it is
one of those hills that is 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 whereyou 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.
·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 will
not have to make turning maneuvers?
·Are there obstructions on the hill that can block your
path (boulders, trees, logs or ruts)?
·What is beyond the hill? Is there a cliff, an
embankment, a drop-off, a fence? Get out and
walk the hill if you do not know. It is the smart way
to ®nd 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.
4-20

{CAUTION:
Getting out on the downhill (low) side of a
vehicle stopped across an incline is
dangerous. If the vehicle rolls over, you could
be crushed or killed. Always get out on the
uphill (high) side of the vehicle and stay well
clear of the rollover path.
Driving in Mud, Sand, Snow or Ice
When you drive in mud, snow or sand, your wheels will
not get good traction. You can not accelerate as
quickly, turning is more difficult, and you will need longer
braking distances.
It is best to use a low gear when you are in mud Ð the
deeper the mud, the lower the gear. In really deep
mud, the idea is to keep your vehicle moving so you do
not get stuck.
When you drive on sand, you will sense a change in
wheel traction. But it will depend upon how loosely
packed the sand is. On loosely packed sand (ason beaches or sand dunes) your tires will tend to sink
into the sand. This has an effect on steering,
accelerating and braking. Drive at a reduced speed and
avoid sharp turns or abrupt maneuvers.
Hard packed snow and ice offer the worst tire traction.
On these surfaces, it is very easy to lose control.
On wet ice, for example, the traction is so poor that you
will have difficulty accelerating. And if you do get
moving, poor steering and difficult braking can cause
you to slide out of control.
{CAUTION:
Driving on frozen lakes, ponds or rivers can be
dangerous. Underwater springs, currents
under the ice, or sudden thaws can weaken the
ice. Your vehicle could fall through the ice and
you and your passengers could drown. Drive
your vehicle on safe surfaces only.
4-26

{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different sizes
or types (radial and bias-belted tires), the
vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes may also cause damage to your vehicle.
Be sure to use the same size and type tires on
all wheels.
Your vehicle may be equipped with a different
size spare than the road tires (those originally
installed on your vehicle). When new, your
vehicle included a spare tire and wheel
assembly with a similar overall diameter as
your vehicle's road tires and wheels, so it is all
right to drive on it. Because this spare was
developed for use on your vehicle, it will not
affect vehicle handling.
{CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rim ¯anges could develop cracks after
many miles of driving. A tire and/or wheel
could fail suddenly, causing a crash. Use only
radial-ply tires with the wheels on your vehicle.
Uniform Tire Quality Grading
Quality grades can be found where applicable on the
tire sidewall between tread shoulder and maximum
section width. For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration, which grades tires by
treadwear, traction and temperature performance.
(This applies only to vehicles sold in the United States.)
The grades are molded on the sidewalls of most
passenger car tires. The Uniform Tire Quality Grading
system does not apply to deep tread, winter-type
snow tires, space-saver or temporary use spare tires,
tires with nominal rim diameters of 10 to 12 inches
(25 to 30 cm), or to some limited-production tires.
5-69

While the tires available on General Motors passenger
cars and light trucks may vary with respect to these
grades, they must also conform to federal safety
requirements and additional General Motors Tire
Performance Criteria (TPC) standards.
Treadwear
The treadwear grade is a comparative rating based on
the wear rate of the tire when tested under controlled
conditions on a speci®ed government test course.
For example, a tire graded 150 would wear one and
a half (1.5) times as well on the government course as
a tire graded 100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart signi®cantly from the norm
due to variations in driving habits, service practices and
differences in road characteristics and climate.
Traction ± AA, A, B, C
The traction grades, from highest to lowest, are AA, A,
B, and C. Those grades represent the tire's ability
to stop on wet pavement as measured under controlled
conditions on speci®ed government test surfaces of
asphalt and concrete. A tire marked C may have poor
traction performance. Warning: The traction grade
assigned to this tire is based on straight-ahead braking
traction tests, and does not include acceleration,
cornering, hydroplaning, or peak traction characteristics.
Temperature ± A, B, C
The temperature grades are A (the highest), B, and C,
representing the tire's resistance to the generation
of heat and its ability to dissipate heat when tested
under controlled conditions on a speci®ed indoor
laboratory test wheel. Sustained high temperature can
cause the material of the tire to degenerate and
reduce tire life, and excessive temperature can lead to
sudden tire failure. The grade C corresponds to a
level of performance which all passenger car tires must
meet under the Federal Motor Vehicle Safety Standard
No. 109. Grades B and A represent higher levels of
performance on the laboratory test wheel than the
minimum required by law.
Warning: The temperature grade for this tire is
established for a tire that is properly in¯ated and not
overloaded. Excessive speed, underin¯ation, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.
5-70

Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You can't know how it's been used
or how far it's been driven. It could fail
suddenly and cause a crash. If you have to
replace a wheel, use a new GM original
equipment wheel.
Tire Chains
{CAUTION:
Don't use tire chains. There's not enough
clearance. Tire chains used on a vehicle without
the proper amount of clearance can cause
damage to the brakes, suspension or other
vehicle parts. The area damaged by the tire
chains could cause you to lose control of your
vehicle and you or others may be injured in a
crash. Use another type of traction device only
if its manufacturer recommends it for use on
your vehicle and tire size combination and road
conditions. Follow that manufacturer's
instructions. To help avoid damage to your
vehicle, drive slowly, readjust or remove the
device if it's contacting your vehicle, and don't
spin your wheels. If you do ®nd traction devices
that will ®t, install them on the rear tires.
5-72

If You Are Stuck in Sand, Mud, Ice or Snow.......4-41
If You Do Decide To Pull A Trailer.....................4-52
Ignition Positions.............................................2-19
Illuminated Visor Vanity Mirrors.........................2-16
Infants and Young Children, Restraints...............1-50
In¯ation - Tire Pressure...................................5-62
Instrument Panel
Cluster.......................................................3-31
Overview..................................................... 3-4
Instrument Panel Brightness.............................3-17
Instrument Panel Fuse Block..........................5-104
Interior Lamps................................................3-17
J
Jump Starting.................................................5-40
K
KEYFOB X BATTERY LOW.............................3-59
Keyless Entry System....................................... 2-4
Keys............................................................... 2-3
L
Lamps
Exterior......................................................3-14
Interior.......................................................3-17Lamps On Reminder.......................................3-15
Lap-Shoulder Belt...........................................1-31
LATCH System
Child Restraints...........................................1-61
Securing a Child Restraint Designed for the
LATCH System........................................1-63
Leaving Your Vehicle With the Engine Running......2-28
LEFT REAR DOOR AJAR................................3-59
Liftgate/Liftglass..............................................2-13
Liftglass/Liftgate..............................................2-13
Light
Air Bag Readiness.......................................3-32
Anti-Lock Brake System Warning...................3-37
Brake System Warning.................................3-36
Charging System.........................................3-35
Cruise Control.............................................3-44
Low Fuel Warning.......................................3-45
Malfunction Indicator....................................3-40
Passenger Air Bag Status Indicator................3-34
Safety Belt Reminder...................................3-32
Security.....................................................3-44
Tire Pressure..............................................3-40
Tow/Haul Mode...........................................3-44
Traction Off................................................3-38
Listening to a DVD.........................................3-79
Loading Your Vehicle.......................................4-44
Loading Your Vehicle for Off-Road Driving..........4-16
Lockout Protection..........................................2-13
Lock-Out Switch.............................................2-15
8

Storage Areas (cont.)
Rear Storage Area.......................................2-45
Storing a Flat or Spare Tire, Jack and Tools.......5-84
Stuck in Sand, Mud, Ice or Snow......................4-41
Sun Visors.....................................................2-16
Sunroof.........................................................2-47
T
Tachometer....................................................3-32
Taillamps.......................................................5-51
Temperature and Compass Display....................2-32
Testing the Alarm............................................2-17
Theft-Deterrent, Radio.....................................3-96
Theft-Deterrent Systems...................................2-16
Content Theft-Deterrent................................2-16
Passlock
ž...................................................2-18
Third Row......................................................1-66
Third Row ± Lap Belt......................................1-40
Throttle, Adjustable..........................................2-21
TIGHTEN FUEL CAP......................................3-62
Tilt Wheel........................................................ 3-7
Tilting the 50/50 Split Bench Seat.....................1-13
Tilting the Full Bench Seat...............................1-18
Tire
Pressure Light.............................................3-40
Tire Sidewall Labeling......................................5-54
Tire Size.......................................................5-58
Tire Terminology and De®nitions........................5-60Tires.............................................................5-54
Buying New Tires........................................5-68
Chains.......................................................5-72
Changing a Flat Tire....................................5-74
If a Tire Goes Flat.......................................5-73
In¯ation - Tire Pressure................................5-62
Inspection and Rotation................................5-66
Pressure Monitor System..............................5-64
Uniform Tire Quality Grading.........................5-69
Wheel Alignment and Tire Balance.................5-71
Wheel Replacement.....................................5-71
When It Is Time for New Tires......................5-68
To Use the Engine Coolant Heater....................2-21
Top Strap......................................................1-57
Top Strap Anchor Location...............................1-59
Torque Lock...................................................2-29
Total Weight on Your Vehicle's Tires..................4-55
Tow/Haul Mode...............................................2-25
Tow/Haul Mode Light.......................................3-44
Towing
Recreational Vehicle.....................................4-44
Towing a Trailer..........................................4-51
Your Vehicle...............................................4-44
Traction
Off Light.....................................................3-38
Stabilitrak
žSystem........................................ 4-9
TRACTION ACTIVE........................................3-64
Traction Control Operation................................4-10
TRACTION SYS LIMITED................................3-63
14