Page 1 of 600

Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-3
Rear Seats
............................................... 1-8
Safety Belts
.............................................1-11
Child Restraints
.......................................1-31
Airbag System
.........................................1-70
Restraint System Check
............................1-87
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
....................................................2-59
OnStar
®System
......................................2-73
Universal Home
Remote System
....................................2-75
Storage Areas
.........................................2-79
Sunroof
..................................................2-82
Vehicle Personalization
.............................2-82
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Climate Controls
......................................3-21
Warning Lights, Gages, and Indicators
........3-31
Driver Information Center (DIC)
..................3-52
Audio System(s)
.......................................3-70Driving 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
......................................................... 5-5
Checking Things Under
the Hood
.............................................5-12
Rear Axle
...............................................5-58
Four-Wheel Drive
.....................................5-59
Front Axle
...............................................5-60
Noise Control System
...............................5-62
Bulb Replacement
....................................5-63
Windshield Wiper Blade Replacement
.........5-71
Tires
......................................................5-72
Appearance Care
...................................5-113
Vehicle Identi cation
...............................5-122
Electrical System
....................................5-123
Capacities and Speci cations
...................5-133
Maintenance Schedule..................................... 6-1
Maintenance Schedule
................................ 6-2
Customer Assistance and Information.............. 7-1
Customer Assistance and Information
........... 7-2
Reporting Safety Defects
...........................7-13
Index................................................................ 1
2006 GMC Sierra Owner ManualM
Page 9 of 600
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.
If your vehicle has a manual bucket or a split bench
seat, you can adjust the seat forward or rearward with
the bar located under the front of the seat cushion.
Lift the bar to unlock the seat. Slide the seat to where you
want it and release the bar. Try to move the seat with
your body to be sure the seat is locked in place.
1-3
Page 12 of 600
Reclining Seatbacks
{CAUTION:
If the seatback is not locked, it could move
forward in a sudden stop or crash. That could
cause injury to the person sitting there. Always
push and pull on the seatback to be sure it is
locked.To adjust the seatback, lift the manual lever located on
the outboard side of the seat. Release the lever to
lock the seatback in the desired position. Lift the lever
again without pushing on the seatback and the seatback
will go to an upright position.
If your vehicle has power seats with a power recliner,
seePower Seats on page 1-4for further information on
how to operate the reclining seatback feature.
1-6
Page 14 of 600

Seatback Latches
The front seatbacks fold forward to allow access to the
rear of the cab.
To fold the seatback forward, lift the lever located on
the outboard side of the seat cushion.
{CAUTION:
If the seatback is not locked, it could move
forward in a sudden stop or crash. That could
cause injury to the person sitting there. Always
push and pull on the seatback to be sure it is
locked.
To return the seatback to the upright position, push the
seatback rearward until it latches. After returning the
seatback to its upright position, push and pull on
the seatback to make sure it is locked.
Rear Seats
Rear Seat Operation (Extended Cab)
Folding the Rear Seat
The rear seat in the extended cab can be folded up to
provide more cargo space.
To fold the seat up, do the following:
1. Push down on the front
of the seat cushion
while pulling down on
the release strap
which is located under
the seat cushion.
2. Pull the seat cushion up until it latches with the
seatback.
3. After latching the seat cushion up, pull forward on it
to make sure it is locked.
1-8
Page 15 of 600

The seat can also be folded down for more seating
space.
To fold the seat down, do the following:
1. Push the seat cushion while pulling the release
strap which is located under the seat cushion.
Pull the seat cushion down until it latches.
2. After latching the seat cushion, pull up on it to
make sure it is locked.
Rear Seat Operation (Crew Cab)
The second row seat is a 60/40 split seat. Either side of
the rear seat may be ipped and folded for added
cargo space.
Make sure that nothing is under or in front of the seat
and that the head restraints are completely lowered.To ip and fold the seat, do the following:
1. Pull up on the strap
loop at the rear of the
seat cushion. Then,
pull the seat cushion up
and ip it forward.
2. After folding the seat cushion fully forward, pull the
seatback forward until it is at. If the seatback
cannot fold at because it interferes with the
cushion, try moving the front seat forward and/or
bringing the front seat more upright. The lever at the
base of the seat must be turned rearward to
release the seatback.
1-9
Page 16 of 600

To return the seat to the normal seating position, do the
following:
1. Lift the seatback up and push it rearward all the way.
{CAUTION:
If the seatback is not locked, it could move
forward in a sudden stop or crash. That could
cause injury to the person sitting there. Always
push and pull on the seatback to be sure it is
locked.
2. Push and pull on the seatback to make sure it is
locked into place.
3. Lower the seat cushion until it latches into position.
Pull up on the cushion to make sure it is locked into
place.
{CAUTION:
A safety belt that is improperly routed, not
properly attached, or twisted will not provide
the protection needed in a crash. The person
wearing the belt could be seriously injured.
After raising the rear seatback, always check
to be sure that the safety belts are properly
routed and attached, and are not twisted.
Make sure that the safety belt buckles on the driver’s
side seatback are accessible to the outboard and center
occupant and are not under the seat cushions.
1-10
Page 22 of 600

Q:If I am a good driver, and I never drive far from
home, why should I wear safety belts?
A:You may be an excellent driver, but if you are in an
accident — even one that is not your fault — you
and your passengers can be hurt. Being a good
driver does not protect you from things beyond your
control, such as bad drivers.
Most accidents occur within 25 miles (40 km)
of home. And the greatest number of serious
injuries and deaths occur at speeds of less than
40 mph (65 km/h).
Safety belts are for everyone.
How to Wear Safety Belts Properly
This part is only for people of adult size.
Be aware that there are special things to know about
safety belts and children. And there are different
rules for smaller children and babies. If a child will be
riding in your vehicle, seeOlder Children on page 1-31
orInfants and Young Children on page 1-33. Follow
those rules for everyone’s protection.
First, you will want to know which restraint systems your
vehicle has.
We will start with the driver position.
Driver Position
Lap-Shoulder Belt
The driver has a lap-shoulder belt. Here is how to wear
it properly.
1. Close and lock the door.
2. Adjust the seat so you can sit up straight. To see
how, see “Seats” in the Index.
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Page 23 of 600
3. Pick up the latch plate and pull the belt across you.
Do not let it get twisted.
The shoulder belt may lock if you pull the belt
across you very quickly. If this happens, let the belt
go back slightly to unlock it. Then pull the belt
across you more slowly.
4. Push the latch plate into the buckle until it clicks.
Pull up on the latch plate to make sure it is secure.
If the belt is not long enough, seeSafety Belt
Extender on page 1-30.
Make sure the release button on the buckle is
positioned so you would be able to unbuckle the
safety belt quickly if you ever had to.5. To make the lap part tight, pull up on the
shoulder belt.
1-17