
The 2003 GMC Yukon DenaIiNukon XL Denali
Owner Manual
Seats and Restraint Systems ........................... 1-1
Front Seats
............................................... 1-3
Rear Seats
............................................... 1-7
Safety Belts
............................................. 1-25
Child Restraints
....................................... 1-48
Air Bag Systems
...................................... 1-72
Restraint System Check
............................ 1-86
Features and Controls ..................................... 2-1
Keys
........................................................ 2-3
Doors and Locks
....................................... 2-8
Windows
................................................. 2-14
Theft-Deterrent Systems
............................ 2-1 6
Starting and Operating Your Vehicle
....... 2-18
Mirrors
.................................................... 2-31
Onstar@
S stem ...................................... 2-36
HomeLink
J Transmitter ............................. 2-38
Storage Areas
......................................... 2-42
Sunroof
.................................................. 2-46
Vehicle Personalization
............................. 2-47
Instrument Panel ............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Warning Lights, Gages and Indicators
......... 3-28
Driver Information Center (DIC)
.................. 3-43
Climate Controls
...................................... 3-1 9
Audio System(s)
....................................... 3-58
Driving Your Vehicle ....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
................................................... 4-44
Service
..................................................... 5-3
Fuel
......................................................... 5-5
Checking Things Under the Hood ............... 5-10
All-Wheel Drive
........................................ 5-46
Rear Axle ............................................... 5-48
Bulb Replacement
.................................... 5-49
Tires
...................................................... 5-55
Appearance Care ..................................... 5-78
Vehicle Identification
................................. 5-86
Electrical System
...................................... 5-87
Capacities and Specifications
..................... 5-96
Normal Maintenance Replacement Parts
...... 5-98
Maintenance Schedule
................................ 6-2
Customer Assistance Information .................... 7-1
Customer Assistance Information
.................. 7-2
Reporting Safety Defects
............................ 7-9
Index ................................................................ 1
Service and Appearance Care .......................... 5-1
Windshield Wiper Blade Replacement
......... 5-54
Maintenance Schedule ..................................... 6-1

Light On Steady - An emission control system
malfunction has been detected on your vehicle.
Dealer or qualified service center diagnosis
and service may be required.
If the Light is Flashing
The following may prevent more serious damage to
your vehicle:
Reducing vehicle speed.
Avoiding hard accelerations.
Avoiding steep uphill grades.
If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible.
If the light stops flashing and remains on steady, see “If
the Light
Is On Steady” following.
If the light continues to flash, when
it is safe to do so,
stop the vehicle. Find a safe place to park your vehicle.
Turn the key
off, wait at least 10 seconds and restart
the engine. If the light remains on steady, see
“If
the Light Is On Steady” following. If the light is still
flashing, follow the previous steps, and drive the vehicle
to your dealer or qualified service center for service.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did
you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install
the cap. See Filling
Your Tank on page 5-7. The
diagnostic system can determine
if the fuel cap has
been left
off or improperly installed. A loose or missing
fuel cap will allow fuel to evaporate into the atmosphere.
A few driving trips with the cap properly installed
should turn the light
off.
Did you just drive through a deep puddle of water?
If so, your electrical system may be wet. The condition
will usually be corrected when the electrical system
dries out. A few driving trips should turn the light
off.
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane
on page 5-5. Poor fuel quality will
cause your engine not to run as efficiently as designed.
You may notice this as stalling after start-up, stalling
when you put the vehicle into gear, misfiring, hesitation
on acceleration or stumbling on acceleration. (These
conditions may go away once the engine is warmed up.)
This will be detected by the system and cause the
light to turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at least
one full tank
of the proper fuel to turn the light off.

Tow/HauI Mode Light
I
This light is displayed
when the tow/haul mode
has been activated.
For more information, see "Tow/Haul Mode" under
Towing a Trailer on page 4-47.
Fuel Gage
United States
Canada
When the ignition is on, the fuel gage tells you about
how much fuel you have left in your tank.
The gage will first indicate empty before you are out of
fuel, and you should get more fuel as
soon as
possible.
Here are some situations you may experience with your
fuel gage. None of these indicate a problem with the
fuel gage.
At the gas station, the fuel pump shuts off before
the gage reads full.
It takes a little more or less fuel to fill up than the
fuel gage indicated. For example, the gage may
have indicated the tank was half full, but
it actually
took a little more or less than half the tank's
capacity to
fill the tank.
The gage goes back to empty when you turn off the
ignition.
Low Fuel Warning Light
The light next to the fuel gage will come on briefly when
you are starting the engine.
This light comes on when the fuel tank is
low on fuel.
To turn it off, add fuel to the fuel tank. See Fuel on
page 5-5.
3-42

Towing Loading Your Vehicle
Towing Your Vehicle
Consult your dealer or a professional towing service if
you need to have your disabled vehicle towed. See
Roadside Assistance Program on page
7-5.
If you want to tow your vehicle behind another vehicle
for recreational purposes (such as behind a motorhome),
see “Recreational Vehicle Towing” following.
Recreational Vehicle Towing
Recreational vehicle towing means towing your vehicle
behind another vehicle
- such as behind a motorhome.
The two most common types of recreational vehicle
towing are known as “dinghy towing” (towing your vehicle
with all four wheels on the ground) and “dolly towing”
(towing your vehicle with two wheels
on the ground and
two wheels
up on a device known as a “dolly”).
Your vehicle was not designed
to be towed with any of
its wheels on the ground.
If your vehicle must be
towed, see Towing Your Vehicle on page
4-44.
Notices Towing an all-wheel-drive vehicle with all
four wheels on the ground, or even with only two
of
its wheels on the ground, will damage drivetrain
components. Don’t tow an all-wheel-drive vehicle
if
any of its wheels will be on the ground.
II II
GAWR FRT GAWR RR
!E mNERS MANUAL FOR ADDITIONAL INFORMATION[-]
The Certificationmire label is found on the rear edge of
the driver’s door.
The label shows the size of your original tires and the
inflation pressures needed
to obtain the gross weight
capacity of your vehicle. This is called the GVWR (Gross
Vehicle Weight Rating). The GVWR includes the
weight of the vehicle, all occupants, fuel and cargo.
The Certificationmire label also tells you the maximum
weights for the front and rear axles, called Gross
Axle Weight Rating (GAWR). To find out the actual loads
on your front and rear axles, you need to go
to a
4-44

To identify the trailering capacity for your vehicle, you
should read the information in “Weight of the Trailer” that
appears later in this section.
If yours was built with trailering options, as many are,
it’s ready for heavier trailers. But trailering is different
than just driving your vehicle by itself. Trailering means
changes in handling, durability and fuel economy.
Successful, safe trailering takes correct equipment, and
it has
to be used properly.
That’s the reason for this part. In it are many time-tested,
important trailering tips and safety rules. Many of
these are important for your safety and that of your
passengers.
So please read this section carefully before
you pull a trailer.
0
0
If You Do Decide To Pull A Trailer
If you do, here are some important points:
There are many different laws, including speed limit
restrictions, having
to do with trailering. Make sure
your rig will be legal, not only where you live
but also where you’ll be driving.
A good source for
this information can be state or provincial police. Consider using a
sway control
if your trailer will
weigh
5,000 Ibs. (2 270 kg) or less. You should
always use a sway control
if your trailer will weigh
more than
5,000 Ibs. (2 270 kg). You can ask a
hitch dealer about sway controls.
Don’t tow a trailer at all during the first
500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.
Then, during the first
500 miles (800 km) that you
tow a trailer, don’t drive over
50 mph (80 km/h)
and don’t make starts at full throttle. This helps your
engine and other parts of your vehicle wear in at
the heavier loads.
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). See “Tow/Haul Mode” under Towing
a
Trailer on page 4-47.
Three important considerations have to do with weight:
0 the weight of the trailer,
the weight of the trailer tongue
0 and the weight on your vehicle’s tires.
4-48

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

Filling Your Tank
Fuel vapor is highly flammable. It burns
violently, and that can cause very bad injuries.
Don’t smoke
if you’re near fuel or refueling
your vehicle. Keep sparks, flames and smoking
materials away from
fuel.
The fuel cap is located behind a hinged door on the
driver’s side of the vehicle.
5-7

While refueling, hang the fuel cap by the tether using
the
hook located on the inside of the filler door.
If you get fuel on yourself and then something
ignites it, you could be badly burned. Fuel can
spray out on you
if you open the fuel cap too
quickly. This spray can happen if your tank is
nearly full, and
is more likely in hot weather.
Open the fuel cap slowly and wait for any “hiss” noise to
stop. Then unscrew the cap all
the way.
Be careful not
to spill fuel. Clean fuel from painted
surfaces as soon
as possible. See Cleaning the Outside
of Your Vehicle on page 5-81.
To remove the fuel cap, turn it slowly to the left
(counterclockwise).
5-8