2003 GMC YUKON Maintenance

Seats and Restraint Systems........................... 1-3
Front Seats
............................................... 1-3
Rear Seats
............................................... 1-8
Safety Belts
.............................................1-22
Child Restraints
.......................................1-44
Air Bag Systems
......................................1-70
Restraint System Check
............................1-86
Features and Controls..................................... 2-1
Keys
........................................................ 2-3
Doors and Locks
....................................... 2-7
Windows
.................................................2-14
Theft-Deterrent Systems
............................2-16
Starting and Operating Your Vehicle
...........2-18
Mirrors
....................................................2-40
OnStar
®System
......................................2-48
HomeLink®Transmitter
.............................2-50
Storage Areas
.........................................2-54
Sunroof
..................................................2-57
Vehicle Personalization
.............................2-58
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Climate Controls
......................................3-21
Warning Lights, Gages and Indicators
.........3-37
Driver Information Center (DIC)
..................3-53
Audio System(s)
.......................................3-71Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
...................................................4-54
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-3
Fuel
......................................................... 5-4
Checking Things Under the Hood
...............5-10
All-Wheel Drive
........................................5-49
Rear Axle
...............................................5-50
Four-Wheel Drive
.....................................5-51
Front Axle
...............................................5-52
Bulb Replacement
....................................5-52
Windshield Wiper Blade Replacement
.........5-59
Tires
......................................................5-60
Appearance Care
.....................................5-88
Vehicle Identication
.................................5-96
Electrical System
......................................5-97
Capacities and Specications
...................5-106
Normal Maintenance Replacement Parts
....5-109
Maintenance Schedule..................................... 6-1
Maintenance Schedule
................................ 6-2
Customer Assistance Information.................... 7-1
Customer Assistance Information
.................. 7-2
Reporting Safety Defects
............................ 7-9
Index................................................................ 1
2003 GMC Yukon/Yukon XLM
2003 - Yukon/Yukon XL

{CAUTION:
Stowing of articles under the passenger’s seat
or between the passenger’s seat cushion and
seatback may interfere with the proper
operation of the passenger sensing system.
Servicing Your Air Bag-Equipped
Vehicle
Air bags affect how your vehicle should be serviced.
There air bag system parts in several places around
your vehicle. You don’t want the system to inflate while
someone is working on your vehicle. Your dealer
and the service manual have information about servicing
your vehicle and the air bag system. To purchase a
service manual, seeService Publications Ordering
Information on page 7-10.
{CAUTION:
For up to 10 minutes after the ignition key is
turned off and the battery is disconnected, an
air bag can still inflate during improper
service. You can be injured if you are close to
an air bag when it inflates. Avoid yellow
connectors. They are probably part of the air
bag system. Be sure to follow proper service
procedures, and make sure the person
performing work for you is qualified to do so.
Air bag systems do not need regular maintenance.
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2003 - Yukon/Yukon XL

Adding Equipment to Your Air
Bag-Equipped Vehicle
Q:Is there anything I might add to the front or
sides of the vehicle that could keep the air
bags from working properly?
A:Yes. If you add things that change your vehicle’s
frame, bumper system, front end or side sheet
metal or height, they may keep the air bag system
from working properly. Also, the air bag system
may not work properly if you relocate any of the air
bag sensors. If you have any questions about
this, you should contact Customer Assistance
before you modify your vehicle. The phone
numbers and addresses for Customer Assistance
are in Step Two of the Customer Satisfaction
Procedure in this manual. SeeCustomer
Satisfaction Procedure on page 7-2.
Restraint System Check
Checking Your Restraint Systems
Now and then, make sure the safety belt reminder light
and all your belts, buckles, latch plates, retractors
and anchorages are working properly. Look for any other
loose or damaged safety belt system parts. If you see
anything that might keep a safety belt system from doing
its job, have it repaired.
Torn or frayed safety belts may not protect you in a
crash. They can rip apart under impact forces. If a belt
is torn or frayed, get a new one right away.
Also look for any opened or broken air bag covers, and
have them repaired or replaced. (The air bag system
does not need regular maintenance.)
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2003 - Yukon/Yukon XL

When your ignition is on, the gage shows the
temperature of the transmissionfluid. The normal
operating range is from 100°F (38°C) to about
265°F (130°C).
At approximately 265°F (130°C), the message center
will display a TRANSMISSION HOT message and
the transmission will enter a transmission protection
mode. When the transmission enters the protection
mode, you may notice a change in the transmission
shifting patterns. The transmission will return to normal
shifting patterns when the transmissionfluid temperature
falls below 260°F (127°C).
SeeDriver Information Center (DIC) on page 3-53for
further information.
If the transmissionfluid reaches temperatures of
approximately 275°F (135°C) or greater, the Driver
Information Center will display a TRANS HOT IDLE
ENG warning message. Pull the vehicle off the roadway
when it is safe to do so. Set the parking brake, place
the transmission in PARK (P) and allow the engine
to idle until the transmission temperature falls below
260°F (127°C). If the transmission continues to operate
above 265°F (130°C), contact your nearest dealer or
the GM Roadside Assistance Center. SeeRoadside
Assistance Program on page 7-5.Notice:If you keep driving your vehicle with the
transmission temperature gage above the normal
operating range, you can damage the transmission.
This could lead to costly repairs that may not be
covered under your warranty.
The following situations can cause the transmission to
operate at higher temperatures:
•Towing a trailer
•Hot outside air temperatures
•Hauling a large or heavy load
•Low transmissionfluid level
•High transmissionfluid level
•Restricted airflow to the radiator and the auxiliary
transmission oil cooler (if equipped).
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures
on a frequent basis, seeScheduled Maintenance
on page 6-5for the proper transmission maintenance
intervals.
3-47
2003 - Yukon/Yukon XL

Malfunction Indicator Lamp
Check Engine Light
Your vehicle is equipped
with a computer which
monitors operation of the
fuel, ignition and emission
control systems.
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended to
assure that emissions are at acceptable levels for the
life of the vehicle, helping to produce a cleaner
environment. The Check Engine light comes on to
indicate that there is a problem and service is required.
Malfunctions often will be indicated by the system
before any problem is apparent. This may prevent more
serious damage to your vehicle. This system is also
designed to assist your service technician in correctly
diagnosing any malfunction.
Notice:If you keep driving your vehicle with this
light on, after a while, your emission controls
may not work as well, your fuel economy may not
be as good and your engine may not run as
smoothly. This could lead to costly repairs that may
not be covered by your warranty.Notice:Modications made to the engine,
transmission, exhaust, intake or fuel system of your
vehicle or the replacement of the original tires
with other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and may cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This may
also result in a failure to pass a required Emission
Inspection/Maintenance test.
This light should come on, as a check to show you it is
working, when the ignition is on and the engine is
not running. If the light doesn’t come on, have it
repaired. This light will also come on during a
malfunction in one of two ways:
•Light Flashing—Amisfire condition has been
detected. A misfire increases vehicle emissions
and may damage the emission control system on
your vehicle. Diagnosis and service may be
required.
•Light On Steady—An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service may be required.
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2003 - Yukon/Yukon XL

Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 5-4. 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.
If none of the above steps have made the light turn off,
your dealer can check the vehicle. Your dealer has the
proper test equipment and diagnostic tools tofix any
mechanical or electrical problems that may have
developed.
Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have or
may begin programs to inspect the emission control
equipment on your vehicle. Failure to pass this
inspection could prevent you from getting a vehicle
registration.Here are some things you need to know to help your
vehicle pass an inspection:
Your vehicle will not pass this inspection if the Check
Engine light is on or not working properly.
Your vehicle will not pass this inspection if the OBD
(on-board diagnostic) system determines that critical
emission control systems have not been completely
diagnosed by the system. The vehicle would be
considered not ready for inspection. This can happen if
you have recently replaced your battery or if your
battery has run down. The diagnostic system is
designed to evaluate critical emission control systems
during normal driving. This may take several days
of routine driving. If you have done this and your vehicle
still does not pass the inspection for lack of OBD
system readiness, your GM dealer can prepare the
vehicle for inspection.
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2003 - Yukon/Yukon XL

Average Fuel Economy
Press the fuel information button until AVG appears in
the display. Average fuel economy is how many
miles per gallon your vehicle is getting based on current
and past driving conditions.
Press and hold the select button while AVG.ECON is
displayed to reset the average fuel economy. Average
fuel economy will then be calculated starting from
that point. If the average fuel economy is not reset, it
will be continually updated each time you drive.
Instant Fuel Economy
Press the fuel information button until INST appears in
the display. Instant fuel economy is how many miles
per gallon your vehicle is at the particular moment
in time. The instant fuel economy cannot be reset.
GM Oil Life System™
Press the fuel information button until ENGINE OIL LIFE
appears in the display. The GM Oil Life System™
shows an estimate of the oil’s remaining useful life. It
will show 100% when the system is reset after an
oil change. It will alert you to change your oil on a
schedule consistent with your driving conditions.Always reset the engine oil life after and oil change. To
reset the Oil Life System press and hold the select
button while ENGINE OIL LIFE is displayed. OIL LIFE
RESET will appear on the display for 10 seconds
to let you know the system is reset.
The DIC does not replace the need to maintain your
vehicle as recommended in the Maintenance Schedule
in this manual. Also, the oil change reminder does
not measure how much oil you have in your engine. So,
be sure to check your oil level often. SeeEngine Oil
on page 5-16.
Personalization Button
You can program certain features to a preferred setting
for up to two people. Press the personalization button
to scroll through the following personalization features.
All of the personalization options may not be available
on your vehicle. only the options available will be
displayed on your DIC.
3-57
2003 - Yukon/Yukon XL

A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures
on a frequent basis, seeScheduled Maintenance
on page 6-5for the proper transmission maintenance
intervals.
DRIVER DOOR AJAR
If the driver’s door is not fully closed, this message will
appear on the display and you will hear a chime.
Stop and turn off the vehicle, check the door for
obstacles, and close the door again. Check to see if the
message still appears on the DIC. Pressing the select
button will acknowledge this message and clear it
from the DIC display.
PASSENGER DOOR AJAR
If the passenger’s door is not fully closed, this message
will appear on the display and you will hear a chime.
Stop and turn off the vehicle, check the door for
obstacles, and close the door again. Check to see if the
message still appears on the DIC. Pressing the select
button will acknowledge this message and clear it
from the DIC display.
LEFT REAR DOOR AJAR
If the driver’s side rear door is not fully closed, this
message will appear on the display and you will hear a
chime. Stop and turn off the vehicle, check the door
for obstacles, and close the door again. Check to see if
the message still appears on the DIC. Pressing the
select button will acknowledge this message and clear it
from the DIC display.
RIGHT REAR DOOR AJAR
If the passenger’s side rear door is not fully closed, this
message will appear on the display and you will hear
a chime. Stop and turn off the vehicle, check the door for
obstacles, and close the door again. Check to see if
the message still appears on the DIC. Pressing
the select button will acknowledge this message and
clear it from the DIC display.
RFA # BATTERY LOW
If a remote keyless entry transmitter battery is low, this
message will appear on the DIC. The battery needs
to be replaced in the transmitter. Pressing the select
button will acknowledge this message and clear it from
the DIC display.
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2003 - Yukon/Yukon XL