
Black plate (4,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
1-4 In Brief
U.StabiliTrak®System on
page 9‑55 (If Equipped).
Ultrasonic Parking Assist on
page 9‑61 (If Equipped).
Pedal Adjust Button
(If Equipped). See Adjustable
Throttle and Brake Pedal on
page 9‑25.
Exhaust Brake (If Equipped).
See “Brakes” in the Duramax
diesel supplement. V.
Power Outlets on page 5‑9.
W. Climate Control Systems (with
Air Conditioning) on page 8‑1 or
Climate Control Systems (with
Heater Only) on page 8‑4
(If Equipped).
Dual Automatic Climate Control
System on page 8‑5
(If Equipped). X. Power Take Off (PTO) Control
(If Equipped). See Power Take
Off (PTO) in the Duramax diesel
supplement.
Y. Passenger Airbag Off Control (If Equipped). See Airbag
On-Off Switch on page 3‑29.

Black plate (7,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
In Brief 1-7
A.Air Vents on page 8‑10.
B. Turn and Lane‐Change Lever. See Turn and Lane-Change
Signals on page 6‑5.
Windshield Wiper/Washer on
page 5‑4.
C. Instrument Cluster on
page 5‑12.
D. Hazard Warning Flashers on
page 6‑5 (Out of View).
E. Shift Lever. See Automatic
Transmission on page 9‑35.
Range Selection Mode
(If Equipped). See Manual
Mode on page 9‑38.
F. Tow/Haul Mode on page 9‑39
(If Equipped).
G. Driver Information Center (DIC) Buttons. See Driver Information
Center (DIC) on page 5‑30. H.
Infotainment on page 7‑1.
I. Exterior Lamp Controls on
page 6‑1.
J. Integrated Trailer Brake Controller (If Equipped). See
Trailer Towing on page 9‑78.
K. Dome Lamps on page 6‑8.
L. Automatic Transfer Case Control (If Equipped). See
Four-Wheel Drive on
page 10‑30.
M. Data Link Connector (DLC) (Out of View). See Malfunction
Indicator Lamp on page 5‑22.
N. Hood Release. See Hood on
page 10‑5.
O. Parking Brake on page 9‑54.
P. Cruise Control on page 9‑58. Q.
Steering Wheel Adjustment on
page 5‑2.
R. Horn on page 5‑4.
S. Steering Wheel Controls on
page 5‑2.
T. Climate Control Systems (with
Air Conditioning) on page 8‑1 or
Climate Control Systems (with
Heater Only) on page 8‑4
(If Equipped).
Dual Automatic Climate
Control System on page 8‑5
(If Equipped).
U. Power Outlets on page 5‑9.
Cigarette Lighter (If Equipped).
See Ashtrays on page 5‑11 and
Cigarette Lighter on page 5‑10.

Black plate (18,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
1-18 In Brief
SeePower Mirrors on page 2‑15.
Keep the selector switch in the
center position when not adjusting
either outside mirror.
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.
Manual Folding Mirrors
If the vehicle has 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.
See Folding Mirrors on page 2‑16. Trailer-Tow Mirrors
If the vehicle has towing mirrors,
they can be adjusted for a clearer
view of the objects behind you.
Manually pull out the mirror head to
extend it for better visibility when
towing a trailer. See
Trailer-Tow
Mirrors on page 2‑15.
Heated Mirrors
For vehicle with heated mirrors:
Press
1to 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
mirrors is not heated.
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 exterior mirrors tilt
to a preselected position when the
vehicle is in R (Reverse). This
feature lets the driver view the curb
when parallel parking. The mirrors
return to the original position
when the vehicle is shifted out of
R (Reverse), or the ignition is turned
off or to OFF/LOCK.
This feature can be programed
through the Driver Information
Center (DIC). See
Vehicle
Personalization (With DIC Buttons)
on page 5‑48 for more information.
Interior Mirror
Adjustment
Hold the rearview mirror in the
center and move it to view the area
behind the vehicle.

Black plate (23,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
In Brief 1-23
Climate Control System (With Heater Only)
A. Fan Control
B. Temperature Control
C. Air Delivery Mode ControlSee
Climate Control Systems (with
Air Conditioning) on page 8‑1 or
Climate Control Systems (with
Heater Only) on page 8‑4.

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 (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 (34,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
3-34 Seats and Restraints
The passenger sensing system is
designed to turn on (may inflate) the
right front passenger frontal airbag
anytime the system senses that a
person of adult size is sitting
properly in the right front
passenger 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, including
children in child restraints, and for
very small adults, the passenger
sensing system may or may not
turn off the right front passenger
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.{WARNING
If the airbag readiness light ever
comes on and stays on, it means
that something may be wrong
with the airbag system. To help
avoid injury to yourself or others,
have the vehicle serviced right
away. See Airbag Readiness
Light on page 5‑18 for more
information, including important
safety information.
If the On Indicator is Lit for a
Child Restraint
If a child restraint has been installed
and the on indicator is lit:
1. Turn the vehicle off.
2. Remove the child restraint from the vehicle. 3. Remove any additional items
from the seat such as blankets,
cushions, seat covers, seat
heaters, or seat massagers.
4. Reinstall the child restraint following the directions
provided by the child restraint
manufacturer and refer to
Securing Child Restraints
(Center Front Seat Position) on
page 3‑58 orSecuring Child
Restraints (Right Front Seat
Position) on page 3‑58 or
Securing Child Restraints (Rear
Seat Position) on page 3‑55.
5. If, after reinstalling the child restraint and restarting the
vehicle, the on indicator is still lit,
turn the vehicle off. Then slightly
recline the vehicle seatback
and adjust the seat cushion,
if adjustable, to make sure that
the vehicle seatback is not
pushing the child restraint into
the seat cushion.

Black plate (35,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Seats and Restraints 3-35
Also make sure the child
restraint is not trapped under the
vehicle head restraint. If this
happens, adjust the head
restraint. SeeHead Restraints
on page 3‑2.
6. Restart the vehicle. The passenger sensing system
may or may not turn off the
airbag for a child in a child
restraint depending upon the
child’s seating posture and body
build. It is better to secure the
child restraint in a rear seat.If the Off Indicator is Lit for an
Adult-Size Occupant
If a person of adult-size is sitting in
the right front passenger seat, but
the off indicator is lit, it could be
because that person is not sitting
properly in the seat. If this happens,
use the following steps to allow the system to detect that person and
enable the right front passenger
frontal airbag:
1. Turn the vehicle off.
2. Remove any additional material
from the seat, such as blankets,
cushions, seat covers, seat
heaters, or seat massagers.
3. Place the seatback in the fully upright position.
4. Have the person sit upright in the seat, centered on the seat
cushion, with legs comfortably
extended.
5. Restart the vehicle and have the person remain in this position for
two to three minutes after the on
indicator is lit.