2003 GMC YUKON DENALI heating

Driving with a Trailer
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon
monoxide (CO) could come into your vehicle.
You can’t see or smell CO.
It can cause
unconsciousness or death. See “Engine
Exhaust” in the Index.
To maximize your safety
when towing a trailer:
Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.
Keep the rear-most windows closed.
If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main
heating or cooling system on and with the
fan on any speed. This will bring fresh,
outside air into your vehicle.
Do not use
the comfort control setting for maximum
air because
it only recirculates the air
inside your vehicle. See “Comfort
1 Controls” in the Index. Towing a trailer requires a certain amount
of experience.
Before setting out for the open road, you’ll want to get
to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the trailer.
And always keep
in mind that the vehicle you are
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check the trailer hitch and platform
(and attachments), safety chains, electrical connector,
lamps, tires and mirror adjustment.
If the trailer has
electric brakes, start your vehicle and trailer moving and
then apply the trailer brake controller by hand to be
sure the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer
brakes are still working.
Following Distance
Stay at least twice as far behind the vehicle ahead a5
you would when driving your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
Passing
You’ll need more passing distance up ahead when
you’re towing a trailer. And, because you’re a good deal
longer, you’ll need to go much farther beyond the
passed vehicle before you can return to your lane.
4-53

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.

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

The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, see Engine Overheating
on
page 5-25.
A 50/50 mixture of clean, drinkable water and
DEX-COOL@ coolant will:
Give freezing protection down to -34°F (-37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
e Let the warning lights and gages work as they
should.
Notice: When adding coolant, it is important that
you use only
DEX-COOL@ (silicate-free) coolant.
If coolant other than DEX-COOL@ is added to the
system, premature engine, heater core or radiator
corrosion may result. In addition, the engine coolant
will require change sooner
-- at 30,000 miles
(50,000 km) or 24 months, whichever occurs first.
Damage caused by the use of coolant other than
DEX-COQL.@ is not covered by your new vehicle
warranty.
What to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL@ coolant which won’t damage
aluminum parts.
!f YOU uss this coolant mixture,
you don’t need
to add anything else.
Adding c..ly
c water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil before the proper coolant mixture will. Your
vehicle’s coolant warning system
is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you wouldn’t get the overheat warning.
Your engine could catch fire and you or others
could be burned. Use a
50/50 mixture of clean,
drinkable water and DEX-COQL@ coolant.
Notice: If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost wouldn’t be covered by your
warranty. Too much water
in the mixture can freeze
and crack the engine, radiator, heater core and
other parts.
5-23

Adding Coolant
If you need more coolant, add the proper DEX-COOL@
coolant mixture
at the surge tank, but only when the
engine
is cool.
1 “J can be burned if you sb... coolant on hot
engine parts. Coolant contains ethylene glycol, and
it will burn if the engine parts are hot
enough. Don’t spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight.
Coolant Surge Tank Pressure Cap
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. See Engine
Compartment Overview on page
5-12 for more
information on location.
Notice: Your pressure cap is a pressure-type cap
and must be tightly installed to prevent coolant
loss
and possible engine damage from overheating.
See “Capacities and Specifications” for more
information.
Engine Overheating
You will find a coolant temperature gage on your
vehicle’s instrument panel. See Engine Coolant
Temperature Gage
on page 3-36. in addition, yoti ill
find a LOW COOLANT, ENGINE COOLANT HOT,
ENGINE OVERHEATED and a REDUCED ENGINE
POWER message in the DIC on the instrument panel.
See DIC Warnings and Messages on page
3-52.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates firing
groups of cylinders helps prevent engine damage.
In
this mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle to
be driven
to a safe place in an emergency. Driving
extended miles (km) and/or towing a trailer in the
overheat protection mode should be avoided.
Notice: After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any repair.
The engine oil will be severely degraded. Repair the cause of coolant
loss, change the oil and reset the oil
life system. See “Engine Oil” in the Index.
5-25

Tires
Your new vehicle comes with high-quality tires made by
a leading tire manufacturer. If you ever have questions
about your tire warranty and where to obtain service,
see your Warranty booklet for details.
Poorly
m-. ltained anc nproperly used 1 !s
are dangerous.
Overloading your tires can cause
overheating as
a result of too much
friction. You could have an air-out and a
serious accident. See “Loading Your
Vehicle”
in the Index.
0 Underinflated tires pose the same danger
as overloaded tires. The resulting accident could cause serious injury. Check all tires
frequently to maintain the recommended
pressure. Tire pressure should be checked
when your tires are cold.
CAUTION: (Continued)
Overinflated tires are more likely to be
cut, punctured or broken by a sudden
impact
- such as when you hit a pothole.
Keep tires at the recommended pressure.
Worn, old tires can cause accidents. If
your tread is badly worn, or if your tires
have been damaged, replace them.
Inflation -- Tire Pressure
The CertificationKire label, which is on the rear edge of
the driver’s door, shows the correct inflation pressures
for your tires when they’re cold. “Cold” means your
vehicle has been sitting for at least three hours
or driven
no more than
1 mile (1.6 km).
5-55

Driving (cont.)
Freeway
....................... ............ 4-33
Hill and Mountain Roads
..., ................... 4-35
In Rain and on Wet Roads
....................... 4-29
winter ........................................................ 4-37
Driving On Grades .......................................... 4-54
Driving on Snow or Ice
.................................... 4-38
Driving Through Deep Standing Water
............... 4-31
Driving Through Flowing Water
......................... 4-31
DVD Driving with a Trailer
....................................... 4-53
Care
of Your ............................................... 3-88
Care
of Your DVD Player ............................. 3-89
Cleaning the Video Screen
........................... 3-89
Distortion .................................................... 3-86
Rear Seat Entertainment System
................... 3-72
DVD Player
.................................................... 3-72 Engine
Air Cleaner/Filter
......................................... 5-17
Battery
....................................................... 5-39
Check and Service Engine Soon Light
............ 3-38
Coolant ...................................................... 5-22
Coolant Heater
............................................ 2-21
Coolant Temperature Gage
........................... 3-36
Cooling System Inspection
............................ 6-14
Engine Compartment Overview
...................... 5-12
Exhaust
..................................................... 2-29
Fan Noise
.................................................. 5-33
Oil
............................................................. 5-13
Overheating
................................................ 5-25
Starting
...................................................... 2-19
Engine Air Cleaner Filter Restriction
Indicator Check
........................................... 6-11
ENGINE COOLANT HOT
................................. 3-53
Engine Coolant Level Check
............................. 6-10
Engine Oil Additives ........................................ 5-16
Engine Oil Level Check
................................... 6-10
Entering or Exiting the Third Row Seats
.............. 1-7
Engine
Oil and Chassis Lubrication Scheduled
Maintenance
................................................. 6-5
ENGINE OVERHEATED
.................................. 3-53
Entertainment System Cleaning the Video Screen
........................... 3-89
DVD Distortion
............................................ 3-86
Entry Lighting
................................................. 3-16
Erasing HomeLink@ Buttons
.............................. 2-41
E
Easy Exit Seat ............................................... 2-48
Electrical System
............................................ 5-87
Add-on Equipment
...................................... 5-87
Fuses and Circuit Breakers
........................... 5-87
Power Windows and Other Power Options
...... 5-87
Windshield Wiper Fuses
............................... 5-87
Electrochromic Mirror Operation
................ 2-32
Emissions Inspection and Maintenance
Programs
....................................... .... 3-40
5

Gasoline Octane
........................................................ 5-5
Gate Operator and Canadian Programming ........ 2-40
Glass surfaces 3-o~
Glove Box ..................................................... 2-42
GM Mobility Program for Persons with
Disabilities
................................... 7-5
Specifications ............................................... 5-5
rn r nn ...............................................
H
Hazard Warning Flashers ............................... 3-5
Head Restraints
........................................... 1-6
Headlamp High/Low-Beam Changer
.................... 3-8
Headlamps
.................................................... 5-49
Bulb Replacement
....................................... 5-49
Front Turn Signal, Sidemarker and Daytime
Running Lamps
........................................ 5-50
Halogen Bulbs ............................................ 5-49
Headphones
................................................... 3-77
Heated Seats
................................................... 1-4
Heating
......................................................... 3-23
Highway Hypnosis
........................................... 4-35
Hill and Mountain Roads
.................................. 4-35
Hitches
.......................................................... 4-52
HomeLink Transmitter, Programming
.................. 2-38
HomeLinkO Transmitter
............................ 2-38
Hood Checking Things Under
................................ 5-10
Release
..................................................... 5-1 0
Horn ............................................................... 3-6
How
to Add Coolant to the Coolant Surge Tank ...... 5-29
How
to Add Fluid ............................................ 5-22
How
to Check ........................................ 5-20, 5-56
How to Check Lhrizzri-it ................................... 5-48
How
to Check Power Steering Fluid .................. 5-34
How
to Use This Manual ...................................... ii
How to Wear Safety Belts Properly ................... 1-30
Hydroplaning
.................................................. 4-31
I
If No Steam Is Coming From Your Engine .......... 5-27
If Steam Is Coming From Your Engine ............... 5-26
If the Light is Flashing
..................................... 3-39
If the Light Is On Steady ................................. 3-39
If You Are Stuck in Sand, Mud, Ice or Snow
....... 4-41
If You Do Decide To Pull
A Trailer ..................... 4-48
If You’re Caught in a Blizzard
........................... 4-39
Ignition Positions
............................................. 2-18
Ignition Transmission Lock Check
...................... 6-13
Illuminated Visor Vanity Mirrors
......................... 2-15
Infants and Young Children, Restraints
............... 1-50
Inflation -- Tire Pressure ..................... ..... 5-55
Inspection
Brake System
............................................. 6-14
Engine Cooling System
................................ 6-14
Exhaust System
.......................................... 6-14
Fuel System
............................................... 6-14
Part C
- Periodic Maintenance ....................... 6-14
7