
Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-3
Rear Seats
............................................... 1-9
Safety Belts
.............................................1-11
Child Restraints
.......................................1-33
Airbag System
.........................................1-66
Restraint System Check
............................1-82
Features and Controls..................................... 2-1
Keys
........................................................ 2-3
Doors and Locks
....................................... 2-8
Windows
.................................................2-16
Theft-Deterrent Systems
............................2-19
Starting and Operating Your Vehicle
...........2-21
Mirrors
....................................................2-55
OnStar
®System
......................................2-64
HomeLink®Transmitter
.............................2-66
Storage Areas
.........................................2-70
Sunroof
..................................................2-73
Vehicle Personalization
.............................2-74
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Climate Controls
......................................3-21
Warning Lights, Gages, and Indicators
........3-31
Driver Information Center (DIC)
..................3-50
Audio System(s)
.......................................3-69Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
........ 4-2
Towing
...................................................4-62
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-4
Fuel
......................................................... 5-6
Checking Things Under the Hood
...............5-12
Rear Axle
...............................................5-58
Four-Wheel Drive
.....................................5-58
Front Axle
...............................................5-60
Noise Control System
...............................5-61
Bulb Replacement
....................................5-62
Windshield Wiper Blade Replacement
.........5-72
Tires
......................................................5-72
Appearance Care
...................................5-112
Vehicle Identi cation
...............................5-120
Electrical System
....................................5-121
Capacities and Speci cations
...................5-130
Maintenance Schedule..................................... 6-1
Maintenance Schedule
................................ 6-2
Customer Assistance and Information.............. 7-1
Customer Assistance and Information
........... 7-2
Reporting Safety Defects
...........................7-10
Index................................................................ 1
2005 GMC Sierra Owner ManualM

6. To tighten the belt, push down on the child restraint,
pull the shoulder portion of the belt to tighten the
lap portion of the belt and feed the shoulder
belt back into the retractor. If you are using a
forward-facing child restraint, you may nd 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 from 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 the airbag is off, the off indicator in the inside
rearview mirror will be lit and stay lit when the
key is turned to RUN or START.
If a child restraint has been installed and the on
indicator is lit, turn the vehicle off. Remove the child
restraint from the vehicle and reinstall the child restraint.
If after reinstalling the child restraint and restarting
the vehicle, the on indicator is still lit, check to make
sure that the vehicle’s seatback is not pressing the child
restraint into the seat cushion. If this happens, slightly
recline the vehicle’s seatback and adjust the seat
cushion if possible. Also make sure the child restraint is
not trapped under the vehicle head restraint. If this
happens, adjust the head restraint.
If the on indicator is still lit, secure the child in the child
restraint in a rear seat position in the vehicle and
check with your dealer.
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.
1-65

the system determines that a small child is present
in a booster seat
a right front passenger takes his/her weight off of
the seat for a period of time
the right front passenger seat is occupied by a
smaller person, such as a child who has outgrown
child restraints
or if there is a critical problem with the airbag
system or the passenger sensing system
When the passenger’s frontal airbag has been turned
off by the passenger sensing system, the off indicator
will light and stay lit to remind you that the airbag is off.
If a child restraint has been installed and the on
indicator is lit, turn the vehicle off. Remove the child
restraint from the vehicle and reinstall the child restraint
following the child restraint manufacturer’s directions
and refer toSecuring a Child Restraint in the Right Front
Seat Position (Regular and Extended Cab) (With
Airbag Off Switch) on page 1-56orSecuring a Child
Restraint in the Right Front Seat Position (Regular and
Extended Cab) (With Passenger Sensing System)
on page 1-62.If after reinstalling the child restraint and restarting the
vehicle, the on indicator is still lit, check to make
sure that the vehicle’s seatback is not pressing the child
restraint into the seat cushion. If this happens, slightly
recline the vehicle’s seatback and adjust the seat
cushion if possible. Also make sure the child restraint is
not trapped under the vehicle head restraint. If this
happens, adjust the head restraint.
If the on indicator is still lit, secure the child in the child
restraint in a rear seat position in the vehicle if one
is available and check with your dealer.
The passenger sensing system is designed to enable
(may in ate) the right front passenger’s frontal
airbag anytime the system senses that a person of adult
size is sitting properly in the right front passenger’s
seat. When the passenger sensing system has allowed
the airbag to be enabled, the on indicator will light
and stay lit to remind you that the airbag is active.
For some children who have outgrown child restraints
and for very small adults, the passenger sensing system
may or may not turn off the right front passenger’s frontal
airbag, depending upon the person’s seating posture
and body build. Everyone in your vehicle who has
outgrown child restraints should wear a safety belt
properly — whether or not there is an airbag for that
person.
1-78

Keys...............................................................2-3
Remote Keyless Entry System.........................2-4
Remote Keyless Entry System Operation...........2-5
Doors and Locks.............................................2-8
Door Locks....................................................2-8
Power Door Locks..........................................2-9
Delayed Locking...........................................2-10
Programmable Automatic Door Locks..............2-10
Rear Door Security Locks (Crew Cab).............2-13
Lockout Protection........................................2-13
Rear Doors..................................................2-14
Tailgate.......................................................2-15
Windows........................................................2-16
Manual Windows..........................................2-16
Power Windows............................................2-17
Swing-Out Windows......................................2-18
Sliding Rear Window.....................................2-18
Sun Visors...................................................2-18
Theft-Deterrent Systems..................................2-19
Content Theft-Deterrent.................................2-19
Passlock
®....................................................2-21
Starting and Operating Your Vehicle................2-21
New Vehicle Break-In....................................2-21
Ignition Positions..........................................2-22
Retained Accessory Power (RAP)...................2-23Starting Your Engine.....................................2-23
Engine Coolant Heater..................................2-25
Automatic Transmission Operation...................2-26
Tow/Haul Mode............................................2-29
Manual Transmission Operation......................2-32
Four-Wheel Drive..........................................2-37
Parking Brake..............................................2-48
Shifting Into Park (P)
(Automatic Transmission)............................2-49
Shifting Out of Park (P)
(Automatic Transmission)............................2-51
Parking Your Vehicle
(Manual Transmission)...............................2-52
Parking Over Things That Burn.......................2-52
Engine Exhaust............................................2-53
Running Your Engine While You Are Parked.......2-54
Mirrors...........................................................2-55
Manual Rearview Mirror.................................2-55
Automatic Dimming Rearview Mirror
with OnStar
®, Compass and
Temperature Display..................................2-55
Automatic Dimming Rearview Mirror with
Compass and Temperature Display..............2-58
Outside Manual Mirrors..................................2-60
Outside Camper-Type Mirrors.........................2-61
Outside West Coast-Type Mirrors....................2-61
Section 2 Features and Controls
2-1