2008 GMC YUKON XL service

Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-2
Rear Seats
..............................................1-11
Safety Belts
.............................................1-30
Child Restraints
.......................................1-51
Airbag System
.........................................1-76
Restraint System Check
............................1-92
Features and Controls..................................... 2-1
Keys
........................................................ 2-3
Doors and Locks
......................................2-10
Windows
.................................................2-19
Theft-Deterrent Systems
............................2-22
Starting and Operating Your Vehicle
...........2-26
Mirrors
....................................................2-49
Object Detection Systems
..........................2-58
OnStar
®System
......................................2-60
Universal Home Remote System
................2-64
Storage Areas
.........................................2-71
Sunroof
..................................................2-74
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Climate Controls
......................................3-23
Warning Lights, Gages, and Indicators
........3-37
Driver Information Center (DIC)
..................3-55
Audio System(s)
.......................................3-81Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
...................................................4-45
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-3
Fuel
......................................................... 5-5
Checking Things Under the Hood
...............5-12
Rear Axle
...............................................5-52
Four-Wheel Drive
.....................................5-54
Front Axle
...............................................5-55
Headlamp Aiming
.....................................5-56
Bulb Replacement
....................................5-59
Windshield Wiper Blade Replacement
.........5-62
Tires
......................................................5-64
Appearance Care
...................................5-108
Vehicle Identication
...............................5-116
Electrical System
....................................5-117
Capacities and Specications
...................5-124
Maintenance Schedule..................................... 6-1
Maintenance Schedule
................................ 6-2
Customer Assistance Information.................... 7-1
Customer Assistance and Information
........... 7-2
Reporting Safety Defects
...........................7-14
Vehicle Data Recording and Privacy
...........7-16
Index................................................................ 1
2008 GMC Yukon, Yukon XL Owner ManualM

If you use the remote keyless entry transmitter to enter
your vehicle and the remote recall memory feature
is on, automatic seat, adjustable mirror, and adjustable
pedal movements will occur. See “MEMORY SEAT
RECALL” underDIC Vehicle Customization (With DIC
Buttons) on page 3-72for more information.
To stop recall movement of the memory function at any
time, press one of the power seat controls, memory
buttons, power mirror buttons, or adjustable pedal
switch.
If something has blocked the driver’s seat and/or the
adjustable pedals while recalling a memory position, the
driver’s seat and/or the adjustable pedals recall may
stop working. If this happens, remove the obstruction
and press the appropriate control for the area that is not
responding for two seconds. Try recalling the memory
position again by pressing the appropriate memory
button. If the memory position is still not recalling, see
your dealer for service.Easy Exit Seat
The control for this feature is located on the driver’s
door panel between buttons 1 and 2.
With the vehicle in PARK (P), the driver’s seat exit
position can be recalled by pressing the exit button. You
will hear a single beep, and the driver’s seat will
move back.
If the easy exit seat feature is programmed in the Driver
Information Center (DIC), automatic seat movement
will occur when the key is removed from the ignition.
See “EASY EXIT SEAT” underDIC Vehicle
Customization (With DIC Buttons) on page 3-72for
more information.
The memory seat and easy exit features can also be
programmed using the DIC.
For programming information, seeDIC Vehicle
Customization (With DIC Buttons) on page 3-72.
1-7

In many crashes severe enough to inate the airbag,
windshields are broken by vehicle deformation.
Additional windshield breakage may also occur from the
right front passenger airbag.
Airbags are designed to inate only once. After an
airbag inates, you will need some new parts for
the airbag system. If you do not get them, the airbag
system will not be there to help protect you in
another crash. A new system will include airbag
modules and possibly other parts. The service
manual for your vehicle covers the need to replace
other parts.
Your vehicle has a crash sensing and diagnostic
module which records information after a crash.
SeeVehicle Data Recording and Privacy on
page 7-16andEvent Data Recorders on page 7-16.
Let only qualied technicians work on the airbag
systems. Improper service can mean that an
airbag system will not work properly. See your
dealer/retailer for service.
Passenger Sensing System
Your vehicle has a passenger sensing system for the
right front passenger’s position. The passenger
airbag status indicator will be visible on the overhead
console when you start your vehicle.
The words ON and OFF, or the symbol for on and off,
will be visible during the system check. When the
system check is complete, either the word ON or the
word OFF, or the symbol for on or the symbol for off, will
be visible. SeePassenger Airbag Status Indicator on
page 3-41.
The passenger sensing system will turn off the right
front passenger’s frontal airbag under certain conditions.
The driver’s airbags are not part of the passenger
sensing system.United States
Canada
1-85

If you ever pull the shoulder portion of the belt out all
the way, you will engage the child restraint locking
feature. This may unintentionally cause the passenger
sensing system to turn the airbag(s) off for some
adult size occupants. If this happens, just let the belt go
back all the way and start again.
{CAUTION:
If the airbag readiness light in the instrument
panel cluster ever comes on and stays on, it
means that something may be wrong with the
airbag system. If this ever happens, have the
vehicle serviced promptly, because an
adult-size person sitting in the right front
passenger’s seat may not have the protection
of the airbag(s). SeeAirbag Readiness Light
on page 3-40for more on this, including
important safety information.A thick layer of additional material, such as a blanket or
cushion, or aftermarket equipment such as seat
covers, seat heaters, and seat massagers can affect
how well the passenger sensing system operates.
We recommend that you not use seat covers or other
aftermarket equipment other than any that GM has
approved for your specic vehicle. SeeAdding
Equipment to Your Airbag-Equipped Vehicle on
page 1-90for more information about modications that
can affect how the system operates.
{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.
1-89

Servicing Your Airbag-Equipped
Vehicle
Airbags affect how your vehicle should be serviced.
There are parts of the airbag system in several places
around your vehicle. Your dealer/retailer and the service
manual have information about servicing your vehicle
and the airbag system. To purchase a service manual,
seeService Publications Ordering Information on
page 7-15.
{CAUTION:
For up to 10 seconds after the ignition is
turned off and the battery is disconnected, an
airbag can still inate during improper service.
You can be injured if you are close to an
airbag when it inates. Avoid yellow
connectors. They are probably part of the
airbag system. Be sure to follow proper
service procedures, and make sure the person
performing work for you is qualied to do so.
Adding Equipment to Your
Airbag-Equipped Vehicle
Q:Is there anything I might add to or change
about the vehicle that could keep the airbags
from working properly?
A:Yes. If you add things that change your vehicle’s
frame, bumper system, height, front end or side
sheet metal, they may keep the airbag system from
working properly. Changing or moving any parts
of the front seats, safety belts, the airbag sensing
and diagnostic module, steering wheel, instrument
panel, roof-rail airbag modules, ceiling headliner
or pillar garnish trim, overhead console, front
sensors, side impact sensors, rollover sensor
module, or airbag wiring can affect the operation of
the airbag system.
1-90

In addition, your vehicle has a passenger sensing
system for the right front passenger’s position,
which includes sensors that are part of the
passenger’s seat. The passenger sensing system
may not operate properly if the original seat
trim is replaced with non-GM covers, upholstery or
trim, or with GM covers, upholstery or trim
designed for a different vehicle. Any object, such as
an aftermarket seat heater or a comfort enhancing
pad or device, installed under or on top of the
seat fabric, could also interfere with the operation of
the passenger sensing system. This could either
prevent proper deployment of the passenger
airbag(s) or prevent the passenger sensing system
from properly turning off the passenger airbag(s).
SeePassenger Sensing System on page 1-85.
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.
If your vehicle has rollover roof-rail airbags, see
Different Size Tires and Wheels on page 5-82
for additional important information.Q:What if I added a snow plow? Will it keep the
airbag from working properly?
A:We have designed our airbag system to work
properly under a wide range of conditions,
including snow plowing with vehicles that have the
optional Snow Plow Prep Package (RPO VYU).
But do not change or defeat the snow plow’s
“tripping mechanism.” If you do, it can damage your
snow plow and your vehicle, and it may cause an
airbag ination.
Q:Because I have a disability, I have to get my
vehicle modied. How can I nd out whether
this will affect my airbag system?
A:If you have questions, call Customer Assistance.
The phone numbers and addresses for Customer
Assistance are in Step Two of the Customer
Satisfaction Procedure in this manual. See
Customer Satisfaction Procedure on page 7-2.
In addition, your dealer/retailer and the service manual
have information about the location of the airbag
sensors, sensing and diagnostic module and airbag
wiring.
1-91

Restraint System Check
Checking the Restraint Systems
Safety Belts
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.
Make sure the safety belt reminder light is working. See
Safety Belt Reminders on page 3-39for more
information.
Keep safety belts clean and dry. SeeCare of Safety
Belts on page 5-111.
Airbags
The airbag system does not need regularly scheduled
maintenance or replacement. Make sure the airbag
readiness light is working. SeeAirbag Readiness Light
on page 3-40for more information.
Notice:If an airbag covering is damaged, opened,
or broken, the airbag may not work properly. Do
not open or break the airbag coverings. If there are
any opened or broken airbag covers, have the
airbag covering and/or airbag module replaced. For
the location of the airbag modules, seeWhat
Makes an Airbag Inflate? on page 1-83. See your
dealer/retailer for service.
1-92

The key has a bar-coded key tag that the dealer/retailer
or qualied locksmith can use to make new keys.
Store this information in a safe place, not in your vehicle.
See your dealer/retailer if a replacement key or
additional key is needed.
Notice:If you ever lock your keys in your vehicle,
you may have to damage the vehicle to get in.
Be sure you have spare keys.
If you are locked out of your vehicle, call the Roadside
Assistance Center. SeeRoadside Assistance Program
on page 7-6.
Remote Keyless Entry (RKE)
System
Your Remote Keyless Entry (RKE) 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.
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.
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
Changes or modications to this system by other than
an authorized service facility could void authorization to
use this equipment.
At times you may notice a decrease in operating range.
This is normal for any RKE system. If the transmitter
does not work or if you have to stand closer to
your vehicle for the transmitter to work, try this:
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” later in this
section.
If you are still having trouble, see your dealer/retailer
or a qualied technician for service.
2-4