
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

These are some examples of vehicle symbols you may find on your vehicle:
CAUTION
POSSIBLE
INJURY
PROTECT EYES BY
SHIELDING
CAUSTIC
BATTERY
ACID COULD CAUSE
BURNS
AVO ID
SPARKS
OR
FLAMES
SPARK
OR
FLAME '\I/'
COULD
EXPLODE BATTERY LATCH BOTH LAP AND
SHOULDER BELTS TO
PROTECT OCCUPANT
4
DO NOT TWIST SAFETY
BELT WHEN ATTACHING
FASTEN SEAT
BELTS
MOVE SEAT DO NOT INSTALL
A REAR-FACING
CHILD RESTRAINT
SECURE IN THIS SEATING
CHILD SEAT POSITION
FULLY
c REARWARD+ /3
PULL BELT DO NOT INSTALL A
COMPLETELY
THEN SECURE
CHILD SEAT FORWARD-FACING
CHILD RESTRAINT IN THIS SEATING
POSITION
POWER DOOR LOCK
WINDOW UNLOCK LIGHTING
- MASTER SWITCH u- 0 ,
LAMPS #O
ENGINE
COOLANT
-FA TEMP -
CHARGING Fl
BATTERY
SYSTEM
ENGINE OIL PRESSURE
9%77
ANTI-LOCK (@)
BRAKES
FUSE BOX
ACCESS
ENGINE
COOLANT FAN
OWNER'S MANUAL
SERVICE
SERVICE MANUAL
V

6. To tighten the belt, feed the shoulder belt back into
the retractor while you push down on the child
restraint. If you are using a forward-facing child
restraint, you may find it helpful to use your knee to
push down on the child restraint as you tighten the
belt. You should not be able to pull more of the belt
out of the retractor once the lock has been set.
7. Push and pull the child restraint in different
directions to be sure it is secure.
8. If your vehicle has the passenger sensing system
and you’re using a rear-facing child restraint in this
seat, check to be sure the right front passenger’s
frontal air bag is off before you begin to drive.
If the
air bag has been turned off the
off indicator will
light and stay lit when the key is turned to RUN or
START.
If the on indicator is lit, the passenger’s frontal air
bag has not been turned
off. If this ever happens,
turn off the vehicle, unbuckle the safety belt
and perform the steps to install the rear-facing
restraint again. After restarting the vehicle,
if the air
bag still doesn’t turn off, install the infant restraint
in
a rear seat position of the vehicle and have your
vehicle serviced as soon as possible.
To remove the child restraint, just unbuckle the vehicle’s
safety belt and let it go back all the way. The safety
belt will move freely again and be ready to work for an
adult or larger child passenger.
1-71

In many crashes severe enough to inflate an air bag,
windshields are broken by vehicle deformation.
Additional windshield breakage may also occur from the
right front passenger air bag.
Air bags are designed to inflate only once. After an
air bag inflates, you’ll need some new parts for
your air bag system. If you don’t get them, the air
bag system won’t be there to help protect you
in another crash.
A new system will include air bag
modules and possibly other parts. The service
manual for your vehicle covers the need to replace
other parts.
Your vehicle is equipped with electronic frontal
sensors which help the sensing system distinguish
between a moderate and a more severe frontal
impact. Your vehicle is also equipped with a crash
sensing and diagnostic module, which records
information about the frontal air bag system. The
module records information about the readiness of
the system and when the system commands
are bag inflation. It records the status
of the driver’s safety belt usage in
a crash in which the air bag
deploys or a crash in which the air bag nearly
deploys. The module also records speed, engine
RPM, brake and throttle data.
Let only qualified technicians work on your air bag
systems. Improper service can mean that an air
bag system won’t work properly. See your dealer for
service.
Notice: If you damage the covering for the driver’s
or the right front passenger’s air bag, or the air
bag covering
on the driver’s and right front
passenger’s seatback, the bag may not work
properly. You may have to replace the air bag
module in the steering wheel, both the air bag
module and the instrument panel for the right front
passenger’s air bag, or both the air bag module
and seatback for the driver’s and right front passenger’s side impact air bag.
Do not open or
break the air bag coverings.
1-80

Your vehicle has one
double-sided key for the
ignition, all door locks
and liftgate.
If you ever lose your keys, your dealer will be able to
assist you with obtaining replacements.
In an emergency contact roadside assistance. See
Roadside Assistance Program on page
7-5.
If you ever lock your keys in your vehicle, you may be
able to have your doors unlocked automatically with the
Onstar@ system
if you have an active Onstar@
subscription. For more information see OnStap System
on page
2-36.
Remote Keyless Entry System
Your keyless entry system operates on a radio
frequency subject
to Federal Communications
Commission
(FCC) Rules and with Industry Canada.
This device complies with Part
15 of the FCC Rules.
Operation is subject
to the following two conditions:
1. This device may not cause interference, and
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
This device complies with
RSS-210 of Industry Canada.
Operation is subject
to the following two conditions:
1. This device may not cause interference, and
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
Changes or modifications
to this system by other than
an authorized service facility could void authorization
to
use this equipment.
2-4

At times you may notice a decrease in range. This is
normal for any remote keyless entry system. If the
transmitter does not work or
if you have to stand closer
to your vehicle for the transmitter to work, try this:
e
e
e
Check the distance. You may be too far from your
vehicle. You may need to stand closer during
rainy or snowy weather.
Check the location. Other vehicles or objects may
be blocking the signal. Take a few steps
to the
left or right, hold the transmitter higher, and
try again.
Check
to determine if battery replacement is
necessary. See “Battery Replacement” under
Remote Keyless Entry System Operation on
page
2-5.
If you are still having trouble, see your dealer or a
qualified technician for service.
Remote Keyless Entry System
Operation
You can lock and unlock your doors from about 3 feet
(1 m) up to 100 feet (30 m) away using the remote
keyless entry transmitter supplied with your vehicle.
a (Unlock): Pressing this
button once will unlock the
driver’s door. The interior
lamps will come on.
Pressing unlock again
within three seconds will
cause the remaining doors
to unlock.
You can choose different feedback options for each
press of the unlock button, such as having the vehicle’s
perimeter lamps come on and/or having the horn
chirp. See
DIC Operation and Displays on page 3-43 for
more information.
2-5

Testing the Alarm Passlock@’
The alarm can be tested by following these steps:
1. From inside the vehicle, lower the driver’s window
and open the driver’s door.
2. Activate the system by locking the doors with the
power door lock switch while the door is open, or
with the remote keyless entry transmitter.
3. Get out of the vehicle, close the door and wait for
the security light
to go out.
4. Then reach in through the window, unlock the door
with the manual door lock and open the door. This
should set
off the alarm.
While the alarm is set, the power door unlock switch is
not operational.
If the alarm does not sound when it should but the
headlamps flash, check
to see if the horn works. The
horn fuse may be blown. To replace the fuse, see Fuses
and Circuit Breakers on page
5-87.
If the alarm does not sound or the headlamps do not
flash, the vehicle should be serviced by your dealer. Your
vehicle is equipped with the Passlock@
theft-deterrent system.
Passlock@ is a passive theft-deterrent system. Passlock@
enables fuel
if the ignition lock cylinder is turned with
a valid key. If a correct key is not used or the ignition
lock cylinder is tampered with, the fuel system is
disabled and the vehicle will not start.
During normal operation, the security light will turn
off
approximately five seconds after the key is turned
to RUN.
If the engine stalls and the security light flashes, wait
about
10 minutes until the light stops flashing before
trying
to restart the engine. Remember to release
the key from START as soon as the engine starts.
If the engine does not start after three tries, the vehicle
needs service.
If the engine is running and the security light comes on,
you will be able to restart the engine
if you turn the engine
off. However, your Passlock@system is not working
properly and must be serviced by your dealer. Your
vehicle is not protected by Passlock@at this time. You
may also want
to check the fuse. See Fuses and Circuit
Breakers
on page 5-87. See your dealer for service.
In an emergency, call the Roadside Assistance Center.
See Roadside Assistance Program
on page 7-5.
3-1 7

Notice: If your key seems stuck in LOCK and you
can’t turn
it, be sure you are using the correct key; if
so, is it all the way in? Turn the key only with
your hand. Using a tool to force
it could break the
key or the ignition switch.
If none of these works,
then your vehicle needs service.
B (ACCESSORY): This position allows you to use
things like the radio, power windows and the windshield
wipers when the engine is
off.
C (RUN): This position is for driving.
D (START): This position starts your engine.
Retained Accessory Power (RAP)
The Retained Accessory Power (RAP) feature will
allow certain features on your vehicle
to continue to
work for up
to 10 minutes after the ignition key is turned
to LOCK.
Starting Your Engine
Move your shift lever to PARK (P) or NEUTRAL (N).
Your engine won’t start in any other position - that’s a
safety feature. To restart when you’re already moving,
use NEUTRAL
(N) only.
Notice: Don’t try to shift to PARK (P) if your
vehicle
is moving. If you do, you could damage the
transaxle. Shift
to PARK (P) only when your
vehicle
is stopped.
1. With your foot
off the accelerator pedal, turn the
ignition key
to START. When the engine starts,
let go of the key. The idle speed will go down as
your engine gets warm.
Notice: Holding your key in START for longer than
15 seconds at a time will cause your battery to
be drained much sooner. And the excessive heat
can damage your starter motor. Wait about
15
seconds between each try to help avoid draining
your battery or damaging your starter.
2. If it doesn’t start within 10 seconds, push the
accelerator pedal all the way
to the floor, while you
hold the ignition key in START. When the engine
starts, let go of the key and let up on the accelerator
pedal. Wait about
15 seconds between each try.
When starting your engine in very cold weather
(below
0°F or -18”C), do this:
1. With your foot off the accelerator pedal, turn the
ignition key to START and hold it there up
to
15 seconds. When the engine starts, let go of
the key.
2-1 5