2003 GMC YUKON DENALI turn signal

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.
4-1 9

City Driving One of the biggest problems with city streets is the
amount of traffic on them. You’ll want
to watch out for
what the other drivers are doing and pay attention
to traffic signals.
Here are ways to increase your safety in city driving:
Know the best way to get to where you are
going. Get a city map and plan your trip into
an unknown part of the city just as you would for a
cross-country trip.
most large cities.
You’ll save time and energy.
See Freeway Driving on page
4-33.
Treat a green light as a warning signal. A traffic
light is there because the corner is busy enough
to need it. When a light turns green, and just before
you start
to move, check both ways for vehicles
that have
not cleared the intersection or may
be running the red light.
Try to use the freeways that rim and crisscross
4-32

Freeway Driving
Mile for mile, freeways (also called thruways, parkways,
expressways, turnpikes or superhighways) are the
safest of all roads. But they have their own special rules. The most important advice
on freeway driving is: Keep
up with traffic and keep to the right. Drive at the
same speed most of the other drivers are driving.
Too-fast or too-slow driving breaks a smooth traffic flow.
Treat the left lane on
a freeway as a passing lane.
At the entrance, there is usually a ramp that leads to the
freeway.
If you have a clear view of the freeway as you
drive along the entrance ramp, you should begin to check
traffic. Try to determine where you expect
to blend with
the flow. Try to merge into the gap at close to the
prevailing speed. Switch on your turn signal, check your
mirrors and glance over your shoulder as often as
necessary. Try to blend smoothly with the traffic flow.
Once you are on the freeway, adjust your speed to the
posted limit or to the prevailing rate
if it’s slower.
Stay in the right lane unless you want to pass.
Before changing lanes, check your mirrors. Then use
your turn signal.
Just before you leave the lane, glance quickly over your
shoulder to make sure there isn’t another vehicle
in
your “blind” spot.
4-33

Automatic Level Control
The automatic level control rear suspension comes as a
part of the AutorideTMsuspension. See AutorideTM on
page
4-46.
This type of level control is fully automatic and will
provide a better leveled riding position as well as better
handling under a variety of passenger and loading
conditions. An air compressor connected
to the rear
shocks will raise or lower the rear of the vehicle
to maintain proper vehicle height. The system is
activated when the ignition key
is turned to RUN and
will automatically adjust vehicle height thereafter.
The system may exhaust (lower vehicle height) for up
to
10 minutes after the ignition key has been turned to
OFF. You may hear the air compressor operating when
the height is being adjusted.
If a weight-distributing hitch is being used, it is
recommended
to allow the shocks to inflate, thereby
leveling the vehicle prior to adjusting the height.
AutorideTM
The AutorideTM feature provides superior vehicle ride
and handling under a variety
of passenger and loading
conditions.
The system is fully automatic and
uses a computer
controller
to continuously monitor vehicle speed, wheel
to body position, IifVdive and steering position of the
vehicle. The controller then sends signals to each shock
absorber
to independently adjust the damping level to
provide the optimum vehicle ride.
AutorideTM also interacts with the towlhaul mode that,
when activated, will provide additional control of
the shock absorbers. This additional control results in
better ride and handling characteristics when the vehicle
is loaded or towing a trailer. See "Tow/Haul Mode"
under Towing a Trailer on page
4-47 for more
information.
4-46

Backing Up
Hold the bottom of the steering wheel with one hand.
Then,
to move the trailer to the left, just move that hand
to the left. To move the trailer to the right, move your
hand
to the right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Notice: Making very sharp turns while trailering
could
cause the trailer to come in contact with the
vehicle. Your vehicle could
be damaged. Avoid
making very sharp turns while trailering.
When you’re turning with a trailer, make wider turns
than normal.
Do this so your trailer won’t strike
soft shoulders, curbs, road signs, trees or other objects.
Avoid jerky or sudden maneuvers. Signal well in
advance.
Turn Signals When Towing a Trailer
The arrows on your instrument panel will flash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also flash, telling other drivers
you’re about
to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument panel will flash for turns even
if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
4-54
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gear before you start
down a long or steep downgrade.
If you don’t shift
down, you might have to use your brakes
so much that
they would get hot and no longer work well.
You can tow in
DRIVE (D). You may want to shift the
transmission
to THIRD (3) or, if necessary, a lower gear
selection
if the transmission shifts too often
(e.g., under heavy loads and/or hilly conditions).
You may also want
to activate the tow/haul mode if the
transmission shifts
too often. See “Tow/Haul Mode”
under Towing a Trailer
on page 4-47.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes.
If you turn your
engine
off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar
to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) for a
few minutes before turning the engine
off. If you do get
the overheat warning, see Engine Overheating
on
page 5-25.

Trailer Wiring Harness
Heavy-Duty Trailer Wiring Package
Your vehicle is equipped with the seven-wire trailer
towing harness. This harness with a seven-pin universal heavy-duty trailer connector
is attached to a bracket
on the hitch platform. The Center High-Mounted Stoplamp
(CHMSL) wire is
tied next
to the trailer wiring harness for use with a
trailer.
The seven-wire harness contains the following trailer
circuits:
0 Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Taillamps
White: Ground
Light Green: Back-up Lamps
0 Red: Battery Feed
Dark Blue: Trailer Brake
4-56

Section 5 Service and Appearance Care
Service ............................................................ 5.3
Doing Your Own Service Work
......................... 5-3
Adding Equipment
to the Outside of Your
Vehicle
.................................................. 5-4
................................................................ Fuel 5.5
Gasoline Octane ............................................ 5.5
Gasoline Specifications ................................... 5-5
California Fuel ............................................... 5-6
Additives
....................................................... 5.6
Fuels in Foreign Countries
............................... 5-6
Filling Your Tank
............................................ 5-7
Filling a Portable Fuel Container ....................... 5.9
the Hood .................... , .................... 5.10
Hood Release ...................... ................ 5-10
Engine Compartment Overview ....... ......... 5-12
Engine Oil ....................................... ..... 5.13
Engine Air Cleaner/Filter ............................. 5.17
Automatic Transmission Fluid ......................... 5-20
Engine Coolant ......................................... 5-22
Checking Things Under
~~
Coolant Surge Tank Pressure Cap ............... 5-25
Engine Overheating ....................................... 5-25
Cooling System ............................................ 5.28
Engine Fan Noise ......................................... 5.33
Power Steering Fluid
..................................... 5-34
Windshield Washer Fluid
................................ 5.34
Brakes
........................................................ 5.36
Battery
........................................................ 5-39
Jump Starting
............................................... 5.40
All-Wheel Drive .............................................. 5.46
Rear Axle .................................. .......... 5-48
Bulb Replacement .......................................... 5-49
Halogen Bulbs .............................................. 5-49
Headlamps
.................................................. 5-49
Running Lamps
......................................... 5-50
Center High-Mounted Stoplamp (CHMSL) ......... 5-52
Taillamps ..................................................... 5-52
Replacement Bulbs ................................... 5.53
Front Turn Signal, Sidemarker and Daytime
5- 1

A. Low-Beam Headlamp
B. High-Beam Headlamp
1. Pull the headlamp assembly out.
2. Unplug the electrical connector.
3. Turn the bulb counterclockwise and remove it from
the headlamp assembly.
4. Put the new bulb into the headlamp assembly and
turn it clockwise until it is tight. Use care not to
touch the bulb with your fingers or hands.
5. Plug in the electrical connector.
6. Put the headlamp assembly back into the vehicle.
7. Install and turn the two pins into the locking feature.
A. Sidemarker Lamp
B. Retainer Clip
C. Front Turn Signal Lamp
D. Daytime Running Lamp
1. Remove the headlamp assembly as mentioned
previously.
5-50