
Black plate (13,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Keys, Doors, and Windows 2-13
Immobilizer Operation
This vehicle has PASS-Key®III+
(Personalized Automotive Security
System) theft-deterrent system.
PASS-Key III+ is a passive
theft-deterrent system.
The system is automatically armed
when the key is removed from the
ignition.
The system is automatically
disarmed when the key is turned
to ON/RUN, ACC/ACCESSORY,
or START from the LOCK/OFF
position.
You do not have to manually arm or
disarm the system.
The security light will come on if
there is a problem with arming or
disarming the theft-deterrent
system.
When the PASS-Key III+ system
senses that someone is using the
wrong key, it prevents the vehicle
from starting. Anyone using a
trial-and-error method to start the vehicle will be discouraged because
of the high number of electrical key
codes.
If the engine does not start and the
security light on the instrument
panel cluster comes on when trying
to start the vehicle, there may be a
problem with the theft-deterrent
system. Turn the ignition off and try
again.
If the engine still does not start, and
the key appears to be undamaged,
try another ignition key. At this time,
you may also want to check the
fuse. See
Fuses and Circuit
Breakers on page 10‑44. If the
engine still does not start with the
other key, the vehicle needs service.
If the vehicle does start, the first key
may be faulty. See your dealer who
can service the PASS-Key III+ to
have a new key made.
It is possible for the PASS-Key III+
decoder to learn the transponder
value of a new or replacement key.
Up to 10 keys may be programmed for the vehicle. The following
procedure is for programming
additional keys only. If all the
currently programmed keys are lost
or do not operate, you must see
your dealer or a locksmith who can
service PASS-Key III+ to have keys
made and programmed to the
system.
See your dealer or a locksmith who
can service PASS-Key III+ to get a
new key blank cut exactly as the
ignition key that operates the
system.
To program the new additional key:
1. Verify that the new key has
a
1stamped on it.
2. Insert the original, already programmed key in the ignition
and start the engine. If the
engine will not start, see your
dealer for service.
3. After the engine has started, turn the key to LOCK/OFF, and
remove the key.

Black plate (14,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
2-14 Keys, Doors, and Windows
4. Insert the new key to beprogrammed and turn it to the
ON/RUN position within
five seconds of turning the
ignition to the LOCK/OFF
position in Step 3.
The security light will turn off
once the key has been
programmed.
5. Repeat Steps 1 through 4 if additional keys are to be
programmed.
If you lose or damage your
PASS-Key III+ key, see your dealer
or a locksmith who can service
PASS-Key III+ to have a new
key made.
Do not leave the key or device
that disarms or deactivates the
theft-deterrent system in the vehicle.Exterior Mirrors
Convex Mirrors
{WARNING
A convex mirror can make things,
like other vehicles, look farther
away than they really are. If you
cut too sharply into the right lane,
you could hit a vehicle on the
right. Check the inside mirror or
glance over your shoulder before
changing lanes.
The passenger side mirror is convex
shaped. A convex mirror's surface is
curved so more can be seen from
the driver seat.
Manual Mirrors
If the vehicle has manual mirrors,
they can be adjusted by moving the
mirror up and down or left to right to
see a little of the side of the vehicle,
and have a clear view behind the
vehicle.
Using hood-mounted air deflectors
and add-on convex mirror
attachments could decrease mirror
performance.

Black plate (21,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Keys, Doors, and Windows 2-21
Window Lockout
Crew Cab Premium Trim Shown,Others Models Similar
o(Window Lockout): The driver
door power window switch has
a lockout feature. This feature
prevents the rear windows from
operating, except from the driver
position. Press the switch to engage
or disengage the lockout feature.
An indicator light on the switch will
come on when the lockout feature is
engaged, and will go off when
disengaged.
Rear Windows
Power Sliding Rear Window
If equipped, the power sliding rear
window works when the ignition has
been turned to ACC/ACCESSORY
or ON/RUN, or when Retained
Accessory Power (RAP) is active. See
Retained Accessory Power
(RAP) on page 9‑29 for more
information.
.Push the switch to open the
window.
.Pull the switch to close the
window.
The power sliding rear window
cannot be operated manually.
Sun Visors
Pull the sun visor down to block
glare. Detach the sun visor from the
center mount to pivot to the side
window, or to extend along the rod,
if available.

Black plate (9,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Seats and Restraints 3-9
Heated and Ventilated
Front Seats
{WARNING
If you cannot feel temperature
change or pain to the skin, the
seat heater may cause burns
even at low temperatures. To
reduce the risk of burns, people
with such a condition should use
care when using the seat heater,
especially for long periods of
time. Do not place anything on
the seat that insulates against
heat, such as a blanket, cushion,
cover, or similar item. This
may cause the seat heater to
overheat. An overheated seat
heater may cause a burn or may
damage the seat.
Heated and Cooled Seat ButtonsShown, Heated Seat Buttons Similar
If available, the buttons are on the
front doors. To operate, the ignition
must be in ON/RUN.
H(Cooled Seat): If available,
press to cool the seat.
I(Heated Seatback): Press
to heat the seatback only.
J(Heated Seat and Seatback):
Press to heat the seat and
seatback. Press the button once for the
highest setting. With each press of
the button, the seat will change to
the next lower setting, and then to
the off setting. The lights indicate
three for the highest setting and one
for the lowest.
The passenger seat may take
longer to heat up.
On vehicles with heated seats,
the heated seats are canceled
10 seconds after the ignition is
turned off.
On vehicles with heated and cooled
seats, the heated and cooled seats
are canceled when the ignition is
turned off.
To use this feature after restarting
the vehicle, press the desired button
again.

Black plate (10,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
3-10 Seats and Restraints
Remote Start Heated Seats
When it is cold outside, the heated
seats may turn on automatically
during a remote vehicle start. The
heated seats will be canceled when
the ignition is turned on. Press the
desired button to use the heated
seats after the vehicle is started.
The lights on the heated seat
buttons do not turn on during a
remote start.
The temperature performance of an
unoccupied seat may be reduced.
This is normal.
SeeRemote Vehicle Start on
page 2‑5.Rear Seats
Rear Seats (Extended
Cab Full Bench)
Folding the Rear Seat
Notice: Folding a rear seat with
the safety belts still fastened may
cause damage to the seat or the
safety belts. Always unbuckle the
safety belts and return them to
their normal stowed position
before folding a rear seat.
To fold the seat:
1. Pull up on the front of the seat cushion while pulling down on
the release strap under the seat
cushion.
2. Pull the seat cushion up until it latches with the seatback.
3. Pull forward on the seat cushion to make sure it is locked in
place.

Black plate (14,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
3-14 Seats and Restraints
.Wear the lap part of the belt
low and snug on the hips, just
touching the thighs. In a crash,
this applies force to the strong
pelvic bones and you would be
less likely to slide under the
lap belt. If you slid under it, the
belt would apply force on your
abdomen. This could cause
serious or even fatal injuries.
.Wear the shoulder belt over the
shoulder and across the chest.
These parts of the body are
best able to take belt restraining
forces. The shoulder belt locks if
there is a sudden stop or crash.
{WARNING
You can be seriously injured,
or even killed, by not wearing
your safety belt properly.
.Never allow the lap or
shoulder belt to become
loose or twisted.
.Never wear the shoulder belt
under both arms or behind
your back.
.Never route the lap or
shoulder belt over an
armrest.
Lap-Shoulder Belt
If the vehicle is a regular cab, then
all seating positions in the vehicle
have a lap-shoulder belt. If the
vehicle is a crew or extended
cab, then all seating positions
in the vehicle have a lap-shoulder
belt except for the center front
passenger position (if equipped),which has a lap belt. See
Lap Belt
(Crew and Extended Cab) on
page 3‑19 for more information.
The following instructions explain
how to wear a lap-shoulder belt
properly.
1. Adjust the seat, if the seat is adjustable, so you can sit up
straight. To see how, see “Seats”
in the Index.
2. Pick up the latch plate and pull the belt across you. Do not let it
get twisted.
The lap-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.
If the shoulder portion of a
passenger belt is pulled out
all the way, the child restraint
locking feature may be engaged.
If this happens, let the belt go
back all the way and start again.

Black plate (20,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
3-20 Seats and Restraints
To make the belt shorter, pull its free
end as shown until the belt is snug.
If the belt is not long enough, see
Safety Belt Extender on page 3‑20.
Make sure the release button on the
buckle is positioned so you would
be able to unbuckle the safety belt
quickly if necessary.
Safety Belt Extender
If the vehicle's safety belt will fasten
around you, you should use it.
But if a safety belt is not long
enough, your dealer will order you
an extender. When you go in to
order it, take the heaviest coat you
will wear, so the extender will be
long enough for you. To help avoid
personal injury, do not let someone
else use it, and use it only for the
seat it is made to fit. The extender
has been designed for adults. Never
use it for securing child seats. To
wear it, attach it to the regular safety
belt. For more information, see the
instruction sheet that comes with
the extender.
Safety System Check
Now and then, check that the safety
belt reminder light, safety belts,
buckles, latch plates, retractors,
and anchorages are all working
properly. Look for any other loose or
damaged safety belt system parts
that might keep a safety belt systemfrom doing its job. See your dealer
to have it repaired. Torn or frayed
safety belts may not protect you in a
crash. They can rip apart under
impact forces. If a belt is torn or
frayed, get a new one right away.
Make sure the safety belt reminder
light is working. See
Safety Belt
Reminders on page 5‑17.
Keep safety belts clean and dry.
See Safety Belt Care on page 3‑20.
Safety Belt Care
Keep belts clean and dry.
{WARNING
Do not bleach or dye safety belts.
It may severely weaken them. In
a crash, they might not be able
to provide adequate protection.
Clean safety belts only with mild
soap and lukewarm water.

Black plate (21,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Seats and Restraints 3-21
Replacing Safety Belt
System Parts after a
Crash
{WARNING
A crash can damage the safety
belt system in the vehicle.
A damaged safety belt system
may not properly protect the
person using it, resulting in
serious injury or even death in a
crash. To help make sure the
safety belt systems are working
properly after a crash, have them
inspected and any necessary
replacements made as soon as
possible.After a minor crash, replacement of
safety belts may not be necessary.
But the safety belt assemblies that
were used during any crash may
have been stressed or damaged.
See your dealer to have the safety
belt assemblies inspected or
replaced.
New parts and repairs may be
necessary even if the safety belt
system was not being used at the
time of the crash.
Have the safety belt pretensioners
checked if the vehicle has been in a
crash, or if the airbag readiness light
stays on after you start the vehicle
or while you are driving. See
Airbag
Readiness Light on page 5‑18.
Airbag System
The vehicle has the following
airbags:
.A frontal airbag for the driver.
.A frontal airbag for the right front
passenger.
The vehicle may have the following
airbags:
.A seat‐mounted side impact
airbag for the driver.
.A seat‐mounted side impact
airbag for the right front
passenger.
.A roof-rail airbag for the driver
and the passenger seated
directly behind the driver.
.A roof-rail airbag for the right
front passenger and the person
seated directly behind the right
front passenger.