
Black plate (5,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Keys, Doors, and Windows 2-5
3. Insert the new battery, positiveside facing down. Replace with a
CR2032 or equivalent battery.
4. Snap the transmitter back together.
Remote Vehicle Start
If available, this feature allows you
to start the engine from outside of
the vehicle. It may also start up the
vehicle's heating or air conditioning
systems and rear window defogger.
Normal operation of the system will
return after the key is turned to the
ON/RUN position.
If the vehicle has an automatic
climate control system, the climate
control system will default to a
heating or cooling mode depending
on the outside temperatures. If the
vehicle does not have an automatic
climate control system, the system
will turn on at the setting the vehicle
was set to when the vehicle was
last turned off. During a remote start, if the vehicle
has an automatic climate control
system and heated seats, the
heated seats will turn on during
colder outside temperatures and will
shut off when the key is turned to
ON/RUN. If the vehicle does not
have an automatic climate control
system, during remote start,
manually turn the heated seats on
and off. See
Heated and Ventilated
Front Seats on page 3‑9 for
additional information.
Laws in some communities may
restrict the use of remote starters.
For example, some laws may
require a person using the remote
start to have the vehicle in view
when doing so. Check local
regulations for any requirements on
remote starting of vehicles.
Do not use the remote start feature
if the vehicle is low on fuel. The
vehicle may run out of fuel. If the vehicle has the remote start
feature, the RKE transmitter
functions will have an increased
range of operation. However, the
range may be less while the vehicle
is running.
There are other conditions which
can affect the performance of the
transmitter. See
Remote Keyless
Entry (RKE) System on page 2‑2 for
additional information.
/(Remote Start): This button will
be on the RKE transmitter if the
vehicle has remote start.
To start the vehicle using the remote
start feature:
1. Aim the RKE transmitter at the
vehicle.
2. Press and release
Q.
3. Immediately press and hold
/until the turn signal
lamps flash. If you cannot see
the vehicle's lamps, press and
hold
/for two to four seconds.

Black plate (17,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Keys, Doors, and Windows 2-17
Manual Folding
If equipped with manual folding
mirrors, push the mirror toward the
vehicle. Push the mirror outward, to
return to its original position.
Manually fold the mirrors inward to
prevent damage when going
through an automatic car wash.
Automatic Dimming
If equipped with an automatic
dimming mirror, the driver outside
mirror automatically dimes for the
glare of the headlamps from behind.
This feature is controlled by the on
and off setting on the inside
rearview mirror.
SeeAutomatic Dimming Rearview
Mirror on page 2‑18.
Turn Signal Indicator
The vehicle may also have a turn
signal indicator on the mirror. An
arrow on the mirror flashes in the
direction of the turn or lane change.
Heated Mirrors
For vehicles with heated mirrors:
1(Rear Window Defogger):
Press to heat the mirrors. If the
vehicle has a towing mirror, only the
upper glass of the mirror is heated.
The lower convex part of the towing
mirror is not heated.
Depending on the vehicle's features,
see “Rear Window Defogger” under
Climate Control Systems (with Air
Conditioning) on page 8‑1 or
Climate Control Systems (with
Heater Only) on page 8‑4 orDual
Automatic Climate Control System
on page 8‑5 for more information.
Park Tilt Mirrors
If the vehicle has the memory
package, the passenger and/or
driver mirror tilts to a preselected
position when the vehicle is in
R (Reverse). This feature lets the
driver view the curb when parallel
parking. The mirror(s) return to the
original position when the vehicle is
shifted out of R (Reverse), or the
ignition is turned off or to
OFF/LOCK.
Turn this feature on or off through
the Driver Information Center (DIC).
SeeVehicle Personalization (With
DIC Buttons) on page 5‑48 for more
information.

Black plate (17,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Seats and Restraints 3-17
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.
Safety Belt Pretensioners
This vehicle has safety belt
pretensioners for front outboard
occupants. Although the safety belt
pretensioners cannot be seen, they
are part of the safety belt assembly.
They can help tighten the safety
belts during the early stages of a
moderate to severe frontal, near
frontal, or rear crash if the threshold
conditions for pretensioner
activation are met. And, if your
vehicle has side impact airbags,
safety belt pretensioners can help
tighten the safety belts in a side
crash or a rollover event.Pretensioners work only once. If the
pretensioners activate in a crash,
they will need to be replaced, and
probably other new parts for the
vehicle's safety belt system. See
Replacing Safety Belt System Parts
after a Crash on page 3‑21.
Rear Safety Belt Comfort
Guides
This vehicle may have rear shoulder
belt comfort guides. If not, they are
available through your dealer. The
guides may provide added safety
belt comfort for older children who
have outgrown booster seats and
for some adults. When installed and
properly adjusted, the comfort guide
positions the belt away from the
neck and head.
Here is how to install a comfort
guide to the shoulder belt:
1. Remove the guide from its
storage clip on the interior body.
2. Place the guide over the beltand insert the two edges of the
belt into the slots of the guide.

Black plate (29,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Seats and Restraints 3-29
other parts. The service manual
for your vehicle covers the need
to replace other parts.
.The vehicle has a crash sensing
and diagnostic module which
records information after a
crash. SeeVehicle Data
Recording and Privacy on
page 13‑19 andEvent Data
Recorders on page 13‑19.
.Let only qualified technicians
work on the airbag systems.
Improper service can mean that
an airbag system will not work
properly. See your dealer for
service.
Airbag On-Off Switch
If one of the switches pictured in the
following illustrations is located in
the glove box, the vehicle has an
airbag on-off switch that you can
use to manually turn on or off the
right front passenger airbag.
United States
Canada and Mexico If the vehicle does not have an
airbag off switch, it may have a
passenger sensing system. See
Passenger Sensing System on
page 3‑32.
This switch should only be turned to
the off position if the person in the
right front passenger position is a
member of a passenger risk
group identified by the national
government as follows:
Infant. An infant (less than 1 year
old) must ride in the front seat
because:
.My vehicle has no rear seat;
.My vehicle has a rear seat too
small to accommodate a
rear-facing infant seat; or
.The infant has a medical
condition which, according to
the infant's physician, makes it
necessary for the infant to ride in
the front seat so that the driver
can constantly monitor the
child's condition.

Black plate (30,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
3-30 Seats and Restraints
Child age 1 to 12. A child
age 1 to 12 must ride in the front
seat because:
.My vehicle has no rear seat;
.Although children ages 1 to 12
ride in the rear seat(s) whenever
possible, children ages 1 to 12
sometimes must ride in the front
because no space is available in
the rear seat(s) of my vehicle; or
.The child has a medical
condition which, according to
the child's physician, makes it
necessary for the child to ride in
the front seat so that the driver
can constantly monitor the
child's condition.
Medical Condition. A passenger
has a medical condition which,
according to his or her physician:
.Causes the passenger airbag to
pose a special risk for the
passenger; and
.Makes the potential harm from
the passenger airbag in a crash
greater than the potential harm from turning off the airbag and
allowing the passenger, even if
belted, to hit the instrument
panel or windshield in a crash.
{WARNING
If the right front passenger airbag
is turned off for a person who is
not in a risk group identified by
the national government, that
person will not have the extra
protection of an airbag. In a
crash, the airbag will not be able
to inflate and help protect the
person sitting there. Do not turn
off the passenger airbag unless
the person sitting there is in a risk
group.
United States
Canada and Mexico

Black plate (32,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
3-32 Seats and Restraints
Passenger Sensing
System
If the vehicle has one of the
indicators pictured in the following
illustrations, then the vehicle has a
passenger sensing system for the
right front passenger position,
unless there is an airbag off switch
located in the glove box. If there is
an airbag off switch, the vehicle
does not have a passenger sensing
system. SeeAirbag On-Off Switch
on page 3‑29 for more information.
The passenger airbag status
indicator will be visible on the
overhead console when the vehicle
is started.
In addition, if the vehicle has a
passenger sensing system for the
right front passenger position, the
label on the vehicle's sun visors
refers to “ADVANCED AIRBAGS”.
United States
Canada and Mexico
The words ON and OFF, or the
symbol for on and off, will be visible
during the system check. If you
are using remote start to start the
vehicle from a distance, if equipped,
you may not see the system
check. When the system check is
complete, either the word ON or
OFF, or the symbol for on or off, will
be visible. See Passenger Airbag
Status Indicator on page 5‑21. The passenger sensing system will
turn off the right front passenger
frontal airbag under certain
conditions. The driver airbag,
seat‐mounted side impact airbags
(if equipped), and the roof-rail
airbags (if equipped) are not
affected by the passenger sensing
system.
The passenger sensing system
works with sensors that are part
of the right front passenger seat
and safety belt. The sensors are
designed to detect the presence
of a properly-seated occupant
and determine if the right front
passenger frontal airbag should be
enabled (may inflate) or not.
According to accident statistics,
children are safer when properly
secured in a rear seat in the correct
child restraint for their weight
and size.

Black plate (38,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
3-38 Seats and Restraints
Q: What if I added a snow plow?Will it keep the airbags from
working properly?
A: We have designed our airbag
systems 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 inflation.
Q: Because I have a disability, I have to get my vehicle
modified. How can I find 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 (U.S.
and Canada) on page 13‑3
or
Customer Satisfaction
Procedure (Mexico) on
page 13‑3.
In addition, your dealer and the
service manual have information
about the location of the airbag
sensors, sensing and diagnostic
module and airbag wiring.
Airbag System Check
The airbag system does not need
regularly scheduled maintenance or
replacement. Make sure the airbag
readiness light is working. See
Airbag Readiness Light on
page 5‑18.
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 airbags, see Where Are the Airbags? on
page 3‑23. See your dealer for
service.
Replacing Airbag System
Parts after a Crash
{WARNING
A crash can damage the
airbag systems in the vehicle.
A damaged airbag system
may not work properly and
may not protect you and your
passenger(s) in a crash, resulting
in serious injury or even death.
To help make sure the airbag
systems are working properly
after a crash, have them
inspected and any necessary
replacements made as soon as
possible.

Black plate (58,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
3-58 Seats and Restraints
6. If the child restraint has a toptether, follow the child restraint
manufacturer's instructions
regarding the use of the top
tether. See Lower Anchors and
Tethers for Children (LATCH
System) on page 3‑47 for more
information.
7. Before placing a child in the child restraint, make sure it is
securely held in place. To
check, grasp the child restraint
at the safety belt path and
attempt to move it side‐to‐side
and back‐and‐forth. When
the child restraint is properly
installed, there should be no
more than 2.5 cm (1 in) of
movement.
To remove the child restraint,
unbuckle the vehicle safety belt and
let it return to the stowed position.
If the top tether is attached to a top
tether anchor, disconnect it.Securing Child Restraints
(Center Front Seat
Position)
{WARNING
A child in a child restraint in the
center front seat can be badly
injured or killed by the frontal
airbags if they inflate. Never
secure a child restraint in the
center front seat. It is always
better to secure a child restraint in
a rear seat.
Do not use child restraints in the
center front seat position.
Securing Child Restraints
(Right Front Seat
Position)
With Passenger Sensing
System
This vehicle has airbags. A rear
seat is a safer place to secure a
forward-facing child restraint. See
Where to Put the Restraint on
page 3‑45.
In addition, the vehicle may have a
passenger sensing system which is
designed to turn off the right front
passenger frontal airbag under
certain conditions. See Passenger
Sensing System on page 3‑32 and
Passenger Airbag Status Indicator
on page 5‑21 for more information
on this, including important safety
information.
A label on the sun visor says,
“Never put a rear-facing child seat in
the front.” This is because the risk to
the rear-facing child is so great,
if the airbag deploys.