Page 18 of 594
Black plate (12,1)GMC Sierra Owner Manual - 2011
1-12 In Brief
Power Lumbar
To adjust the power lumbar support,
if equipped:
.On vehicles with two-way
lumbar, press and hold the
top or bottom of the control to
increase or decrease lumbar
support.
.On vehicles with four-way
lumbar, press and hold the
front or rear of the control to
increase or decrease lumbar
support. To raise or lower the
height of the support, press
and hold the top or bottom
of the control.
See Lumbar Adjustment on
page 3‑6 for more information.Reclining Seatbacks
Manual Reclining Seatbacks
To recline a manual seatback:
1. Lift the lever.
2. Move the seatback to the
desired position, and then
release the lever to lock the
seatback in place.
3. Push and pull on the seatback to make sure it is locked.
Page 21 of 594
Black plate (15,1)GMC Sierra Owner Manual - 2011
In Brief 1-15
Heated Seats
If available, the controls are on the
driver and passenger doors.
I:Press to heat the
seatback only.
J: Press to heat the seat and
seatback.
See Heated Front Seats on
page 3‑8.
Head Restraint
Adjustment
Do not drive until the head restraints
for all occupants are installed and
adjusted properly.
To achieve a comfortable seating
position, change the seatback
recline angle as little as necessary
while keeping the seat and the
head restraint height in the proper
position.
For more information see Head
Restraints on page 3‑2 andSeat
Adjustment on page 3‑3.
Safety Belts
Refer to the following sections for
important information on how to use
safety belts properly.
.Safety Belts on page 3‑11.
.How to Wear Safety Belts
Properly on page 3‑15.
.Lap-Shoulder Belt on page 3‑21.
.Lower Anchors and Tethers for
Children (LATCH System) on
page 3‑57.
Page 70 of 594
Black plate (2,1)GMC Sierra Owner Manual - 2011
3-2 Seats and Restraints
Head Restraints
The front seats have adjustable
head restraints in the outboard
seating positions.
{WARNING
With head restraints that are
not installed and adjusted
properly, there is a greater
chance that occupants will suffer
a neck/spinal injury in a crash.
Do not drive until the head
restraints for all occupants are
installed and adjusted properly.
Adjust the head restraint so that the
top of the restraint is at the same
height as the top of the occupant's
head. This position reduces the
chance of a neck injury in a crash.Pull the head restraint up to raise it.
To lower the head restraint, press
the button, located on the top
of the seatback, and push the
restraint down.
Push down on the head restraint
after the button is released to make
sure that it is locked in place.
The head restraints are not
designed to be removed.
The rear seat has headrests that
can be adjusted up and down.
Page 74 of 594

Black plate (6,1)GMC Sierra Owner Manual - 2011
3-6 Seats and Restraints
Lumbar Adjustment
Manual Lumbar
If equipped, increase or decrease
manual lumbar support by turning
the knob forward or rearward.
Power Lumbar
To adjust the power lumbar support,
if equipped:
.On vehicles with two-way
lumbar, press and hold the
top or bottom of the control to
increase or decrease lumbar
support.
.On vehicles with four-way
lumbar, press and hold the front
or rear of the control to increase
or decrease lumbar support.
To raise or lower the height of
the support, press and hold the
top or bottom of the control.
Reclining Seatbacks
{WARNING
Sitting in a reclined position when
the vehicle is in motion can be
dangerous. Even when buckled
up, the safety belts cannot do
their job when reclined like this.
The shoulder belt cannot do its
job because it will not be against
your body. Instead, it will be in
front of you. In a crash, you could
go into it, receiving neck or other
injuries.
The lap belt cannot do its job
either. In a crash, the belt could
go up over your abdomen.
The belt forces would be
there, not at your pelvic bones.
This could cause serious
internal injuries.(Continued)
Page 90 of 594

Black plate (22,1)GMC Sierra Owner Manual - 2011
3-22 Seats and Restraints
3. Push the latch plate into thebuckle until it clicks.
Pull up on the latch plate to
make sure it is secure. If the belt
is not long enough, see Safety
Belt Extender on page 3‑27.
If the latch plate will not go fully
into the buckle, check if the
correct buckle is being used.
Position the release button on
the buckle so that the safety belt
could be quickly unbuckled if
necessary. 4. If equipped with a shoulder belt
height adjuster, move it to the
height that is right for you. See
“Shoulder Belt Height Adjuster”
later in this section.
5. To make the lap part tight, pull
up on the shoulder belt.
It may be necessary to pull
stitching on the safety belt
through the latch plate to fully
tighten the lap belt on smaller
occupants.
To unlatch the belt, push the button
on the buckle. The belt should
return to its stowed position.
Before a door is closed, be sure the
safety belt is out of the way. If a
door is slammed against a safety
belt, damage can occur to both the
safety belt and the vehicle.
Page 91 of 594

Black plate (23,1)GMC Sierra Owner Manual - 2011
Seats and Restraints 3-23
Shoulder Belt Height Adjuster
The vehicle has a shoulder belt
height adjuster for the driver and
right front passenger.
Adjust the height so the shoulder
portion of the belt is on the
shoulder and not falling off of it.
The belt should be close to, but
not contacting, the neck. Improper
shoulder belt height adjustment
could reduce the effectiveness of
the safety belt in a crash. SeeHow
to Wear Safety Belts Properly on
page 3‑15.
Regular and Crew Cab
To move the adjuster down for the
regular and crew cabs, squeeze
the buttons (A) on the sides of the
height adjuster and move the height
adjuster to the desired position.Extended Cab
On the extended cab, push down
on the release button (A) and move
the height adjuster to the desired
position.
You can move the adjuster up just
by pushing up on the shoulder belt
guide.
After you move the adjuster to
where you want it, try to move it
down, without squeezing the buttons
for the regular and crew cabs,
or without pushing the release
button for extended cabs, to make
sure it has locked into position.
Page 114 of 594

Black plate (46,1)GMC Sierra Owner Manual - 2011
3-46 Seats and Restraints
Servicing the
Airbag-Equipped Vehicle
Airbags affect how the vehicle
should be serviced. There are
parts of the airbag system in
several places around the vehicle.
Your dealer and the service manual
have information about servicing
the vehicle and the airbag system.
To purchase a service manual, see
Service Publications Ordering
Information on page 13‑15.
{WARNING
For up to 10 seconds after the
ignition is turned off and the
battery is disconnected, an airbag
can still inflate during improper
service. You can be injured if you
are close to an airbag when it
inflates. 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 qualified to do so.
Adding Equipment to the
Airbag-Equipped Vehicle
Q: Is there anything I might addto 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,
or airbag wiring can affect the
operation of the airbag system.
Page 117 of 594

Black plate (49,1)GMC Sierra Owner Manual - 2011
Seats and Restraints 3-49
If an airbag inflates, you will need
to replace airbag system parts.
See your dealer for service.
If the airbag readiness light stays on
after the vehicle is started or comes
on when you are driving, the airbag
system may not work properly.
Have the vehicle serviced right
away. SeeAirbag Readiness Light
on page 5‑20 for more information.Child Restraints
Older Children
Older children who have outgrown
booster seats should wear the
vehicle safety belts. The manufacturer's instructions that
come with the booster seat state the
weight and height limitations for that
booster. Use a booster seat with
a lap-shoulder belt until the child
passes the fit test below:
.Sit all the way back on the seat.
Do the knees bend at the seat
edge? If yes, continue. If no,
return to the booster seat.
.Buckle the lap-shoulder belt.
Does the shoulder belt rest on
the shoulder? If yes, continue.
If no, try using the rear safety
belt comfort guide. See
“Rear
Safety Belt Comfort Guides”
under Lap-Shoulder Belt on
page 3‑21 for more information.
If the shoulder belt still does not
rest on the shoulder, then return
to the booster seat.