GMC SIERRA 2008 Owner's Manual

Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-3
Rear Seats
..............................................1-12
Safety Belts
.............................................1-14
Child Restraints
.......................................1-35
Airbag System
.........................................1-68
Restraint System Check
............................1-87
Features and Controls..................................... 2-1
Keys
........................................................ 2-3
Doors and Locks
......................................2-10
Windows
.................................................2-15
Theft-Deterrent Systems
............................2-18
Starting and Operating Your Vehicle
...........2-22
Mirrors
....................................................2-55
Object Detection Systems
..........................2-63
OnStar
®System
......................................2-65
Universal Home Remote System
................2-68
Storage Areas
.........................................2-74
Sunroof
..................................................2-79
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Climate Controls
......................................3-25
Warning Lights, Gages, and Indicators
........3-34
Driver Information Center (DIC)
..................3-54
Audio System(s)
.......................................3-80Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
...................................................4-50
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-4
Fuel
......................................................... 5-6
Checking Things Under the Hood
...............5-12
Rear Axle
...............................................5-51
Four-Wheel Drive
.....................................5-52
Front Axle
...............................................5-54
Noise Control System
...............................5-56
Headlamp Aiming
.....................................5-56
Bulb Replacement
....................................5-59
Windshield Wiper Blade Replacement
.........5-65
Tires
......................................................5-66
Appearance Care
...................................5-112
Vehicle Identication
...............................5-121
Electrical System
....................................5-122
Capacities and Specications
...................5-130
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 Sierra Owner ManualM

GENERAL MOTORS, GM, the GM Emblem, GMC, the
GMC Truck Emblem, and the name SIERRA are
registered trademarks of General Motors Corporation.
This manual includes the latest information at the time it
was printed. We reserve the right to make changes
after that time without further notice. For vehicles rst
sold in Canada, substitute the name “General Motors of
Canada Limited” for GMC whenever it appears in this
manual.
This manual describes features that may be available in
this model, but your vehicle may not have all of them.
For example, more than one entertainment system may
be offered or your vehicle may have been ordered
without a front passenger or rear seats.
Keep this manual in the vehicle for quick reference.
Canadian Owners
A French language copy of this manual can be obtained
from your dealer/retailer or from:
Helm, Incorporated
P.O. Box 07130
Detroit, MI 48207
1-800-551-4123
www.helminc.com
Propriétaires Canadiens
On peut obtenir un exemplaire de ce guide en français
auprès de concessionnaire ou à l’adresse suivante:
Helm Incorporated
P.O. Box 07130
Detroit, MI 48207
1-800-551-4123
www.helminc.com
Litho in U.S.A.
Part No. 15854802 A First Printing
©2007 General Motors Corporation. All Rights Reserved.
ii

Using this Manual
Many people read the owner manual from beginning to
end when they rst receive their new vehicle. If this
is done, it can help you learn about the features
and controls for the vehicle. Pictures and words work
together in the owner manual to explain things.
If your vehicle has the DURAMAX
®Diesel engine, refer
to the DURAMAX®Diesel supplement for additional
and specic information on this engine.
Index
A good place to quickly locate information about the
vehicle is the Index in the back of the manual. It is an
alphabetical list of what is in the manual and the
page number where it can be found.
Safety Warnings and Symbols
There are a number of safety cautions in this book. A
box with the word CAUTION is used to tell about things
that could hurt you or others if you were to ignore the
warning.
{CAUTION:
These mean there is something that could hurt
you or other people.
We tell you what the hazard is and what to do to help
avoid or reduce the hazard. Please read these cautions.
If you do not, you or others could be hurt.
A circle with a slash
through it is a safety
symbol which means “Do
Not,” “Do Not do this”
or “Do Not let this happen.”
iii

Vehicle Damage Warnings
You will also nd notices in this manual.
Notice:These mean there is something that could
damage your vehicle.
A notice tells about something that can damage the
vehicle. Many times, this damage would not be covered
by your vehicle’s warranty, and it could be costly.
The notice tells what to do to help avoid the damage.
When you read other manuals, you might see
CAUTION and NOTICE warnings in different colors
or in different words.
There are also warning labels on the vehicle which use
the same words, CAUTION or NOTICE.
Vehicle Symbols
The vehicle has components and labels that use
symbols instead of text. Symbols are shown along with
the text describing the operation or information
relating to a specic component, control, message,
gage, or indicator.
iv

Front Seats......................................................1-3
Manual Seats................................................1-3
Power Seats..................................................1-4
Manual Lumbar..............................................1-5
Power Lumbar...............................................1-5
Heated Seats.................................................1-6
Memory Seat, Mirrors, and Pedals....................1-6
Reclining Seatbacks........................................1-8
Head Restraints............................................1-10
Seatback Latches.........................................1-11
Center Seat.................................................1-12
Rear Seats.....................................................1-12
Rear Seat Operation (Full Bench)...................1-12
Rear Seat Operation (Split Bench)..................1-13
Safety Belts...................................................1-14
Safety Belts: They Are for Everyone................1-14
How to Wear Safety Belts Properly.................1-19
Lap-Shoulder Belt.........................................1-28
Safety Belt Use During Pregnancy..................1-33
Lap Belt (Crew and Extended Cab).................1-34
Safety Belt Extender.....................................1-35Child Restraints.............................................1-35
Older Children..............................................1-35
Infants and Young Children............................1-38
Child Restraint Systems.................................1-42
Where to Put the Restraint.............................1-44
Lower Anchors and Tethers for Children
(LATCH)..................................................1-45
Securing a Child Restraint in a Rear Seat
Position...................................................1-55
Securing a Child Restraint in the Center Front
Seat Position............................................1-57
Securing a Child Restraint in the Right Front
Seat Position (With Airbag Off Switch)..........1-58
Securing a Child Restraint in the Right Front
Seat Position (With Passenger Sensing
System)...................................................1-62
Securing a Child Restraint in the Right
Front Seat Position (Heavy Duty Crew
Cab Only)...............................................
.1-66
Section 1 Seats and Restraint Systems
1-1

Airbag System...............................................1-68
Where Are the Airbags?................................1-71
When Should an Airbag Inate?.....................1-73
What Makes an Airbag Inate?.......................1-74
How Does an Airbag Restrain?.......................1-74
What Will You See After an Airbag Inates?.....1-75
Airbag Off Switch..........................................1-76Passenger Sensing System............................1-80
Servicing Your Airbag-Equipped Vehicle...........1-84
Adding Equipment to Your Airbag-Equipped
Vehicle....................................................1-85
Restraint System Check..................................1-87
Checking the Restraint Systems......................1-87
Replacing Restraint System Parts After
a Crash...................................................1-88
Section 1 Seats and Restraint Systems
1-2

Front Seats
Manual Seats
{CAUTION:
You can lose control of the vehicle if you try to
adjust a manual driver’s seat while the vehicle
is moving. The sudden movement could startle
and confuse you, or make you push a pedal
when you do not want to. Adjust the driver’s
seat only when the vehicle is not moving.To move a manual seat forward or rearward:
1. Lift the bar to unlock
the seat.
2. Slide the seat to the
desired position and
release the bar.
Try to move the seat with your body to be sure the seat
is locked in place.
1-3

Power SeatsOn a vehicle with power seats, the controls used to
operate them are located on the outboard side of the
seats. To adjust the seat, do any of the following:
Move the seat forward or rearward by sliding the
control forward or rearward.
Raise or lower the front part of the seat cushion by
moving the front of the control up or down.
Raise or lower the rear part of the seat cushion by
moving the rear of the control up or down.
Raise or lower the entire seat by moving the entire
control up or down.
On seats with power reclining seatbacks, the control is
located behind the power seat control on the outboard
side of the seats. See “Power Reclining Seatbacks”
underReclining Seatbacks on page 1-8.
A vehicle with a memory function allows seat settings to
be saved and recalled. SeeMemory Seat, Mirrors,
and Pedals on page 1-6for more information. Driver’s Seat with Power Seat Control, Power
Recline, and Power Lumbar shown
1-4

Manual Lumbar
On vehicles with this feature, turn the knob forward or
rearward to increase or decrease lumbar support.
Power Lumbar
If the seats have power lumbar, the controls used to
operate this feature are located on the outboard side of
the seats.
To increase lumbar support, press and hold the
front of the control.
To decrease lumbar support, press and hold the
rear of the control.
To raise the height of the lumbar support, press
and hold the top of the control.
To lower the height of the lumbar support, press
and hold the bottom of the control.
1-5

Release the control when the lower seatback reaches
the desired level of lumbar support.
Your vehicle may have a memory function which allows
seat settings to be saved and recalled. SeeMemory
Seat, Mirrors, and Pedals on page 1-6for more
information.
Keep in mind that as your seating position changes, as
it may during long trips, so should the position of
your lumbar support. Adjust the seat as needed.
Heated Seats
On vehicles with heated front seats, the controls are
located on the driver’s and passenger’s doors.
I(Heated Seatback):Press to turn on the heated
seatback.
J(Heated Seat and Seatback):Press to turn on the
heated seat and seatback.
The light on the button will come on to indicate that the
feature is working. Press the button to cycle through
the temperature settings of high, medium, and low and
to turn the heat to the seat off. Indicator lights will
show the level of heat selected: three for high, two for
medium, and one for low.The heated seats will be canceled ten seconds after the
ignition is turned off. To use the heated seat feature
after restarting your vehicle, press the heated seat
or seatback button again.
Memory Seat, Mirrors, and Pedals
Your vehicle may have the memory package.
The controls for this
feature are located on the
driver’s door panel, and
are used to program
and recall memory settings
for the driver’s seat,
outside mirrors, and the
adjustable throttle and
brake pedal.
To save your positions in memory, do the following:
1. Adjust the driver’s seat, including the seatback
recliner and lumbar, both outside mirrors, and
the throttle and brake pedals to a comfortable
position.
1-6