climate control GMC SIERRA 1500 2012 Owner's Manual

Black plate (3,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Climate Controls 8-3
#(Air Conditioning):Press to
turn the air conditioning system on
or off. An indicator light comes on to
show that the air conditioning is on.
The air conditioning can be selected
in any mode as long as the fan
switch is on.
The air conditioning system
removes moisture from the air, so a
small amount of water might drip
under the vehicle while idling or
after turning off the engine. This is
normal.Rear Window Defogger
For vehicles with a rear window
defogger, a warming grid is used to
remove fog from the rear window.
1(Rear): Press to turn the rear
window defogger on or off. An
indicator light on the button comes
on to show that the rear window
defogger is on.
The rear window defogger only
works when the ignition is in ON/
RUN. The rear window defogger
stays on for approximately
10 minutes after the button is
pressed, unless the ignition is
turned to ACC/ACCESSORY or
LOCK/OFF. The defogger can also
be turned off by turning off the
engine. Notice:
Do not use anything
sharp on the inside of the rear
window. If you do, you could cut
or damage the warming grid, and
the repairs would not be covered
by the vehicle warranty. Do not
attach a temporary vehicle
license, tape, a decal, or anything
similar to the defogger grid.

Black plate (4,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
8-4 Climate Controls
Climate Control Systems (with Heater Only)
With this system the heating and ventilation can be controlled.
A. Fan Control
B. Temperature Control
C. Air Delivery Mode Control
Temperature Control:Turn
clockwise or counterclockwise
to increase or decrease the
temperature inside the vehicle.9(Fan Control): Turn clockwise
or counterclockwise to increase or
decrease the fan speed. Turn the
knob all the way counterclockwise
to turn the front system off.
Air Delivery Mode Control: Turn
clockwise or counterclockwise
to increase or decrease the
temperature inside the vehicle. The knob can be positioned
between two modes to select a
combination of those modes.
Select from the following:
H(Vent):
Air is directed to the
instrument panel outlets.
)(Bi-Level): Air is divided
between the instrument panel and
floor outlets.
6(Floor): Air is directed to the
floor outlets, with some air directed
to the windshield, side window, and
second row floor outlets. In this
mode, the system automatically
selects outside air.
-(Defog): This mode clears the
windows of fog or moisture. Air is
directed to the windshield, floor
outlets, and side window vents.

Black plate (5,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Climate Controls 8-5
0(Defrost):This mode removes
fog or frost from the windshield
more quickly. Air is directed to the
windshield and the side window
vents, with some air directed
to the floor vents. The system
automatically forces outside air into
the vehicle.
Do not drive the vehicle until all the
windows are clear.Dual Automatic Climate Control System
The heating, cooling, and ventilation in the vehicle can be controlled with
this system. The vehicle also has a flow-through ventilation system
described later in this section.
A. Driver and Passenger Temperature Controls
B. Fan Control
C. AUTO
D. Defrost
E. Recirculation
F. Outside Air G. Air Delivery Mode Control
H. Display
I. On/Off
J. Rear Window Defogger
K. Air Conditioning
L. PASS (Passenger)

Black plate (6,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
8-6 Climate Controls
O(On/Off):Press to turn the
climate control system on or off.
Outside air still enters the vehicle,
and is directed to the floor. This
direction can be changed by
pressing the mode button.
Recirculation can be selected once
you have selected vent or bi-level
mode. The temperature can also be
adjusted using either temperature
button. If the air delivery mode or
temperature settings are adjusted
with the system off, the display
illuminates briefly to show the
settings and then returns to off. The
system can be turned back on by
pressing either
O,D,C,#, the
defrost or the AUTO button.
Driver and Passenger Side
Temperature Controls
The driver and passenger side
temperature buttons are used to
adjust the temperature of the air
coming through the system on the
driver or passenger side of the
vehicle. The temperature can be
adjusted even if the system is turned off. This is possible since
outside air always flows through
the system as the vehicle is
moving forward unless it is
set to recirculation mode. See
“Recirculation”
later in this section.
Press the + or −buttons to increase
or decrease the cabin temperature.
The driver side or passenger side
temperature display shows the
temperature setting increasing or
decreasing.
The passenger temperature setting
can be set to match the driver
temperature setting by pressing
the PASS button and turning
off the PASS indicator. When the
passenger temperature setting is
set different than the driver setting,
the indicator on the PASS button
illuminates and both the driver side
and passenger side temperature
displays are shown.
When in defrost mode the
passenger temperature setting
cannot be changed.
Automatic Operation
AUTO (Automatic): When
automatic operation is active,
the system controls the inside
temperature, the air delivery, and
the fan speed.
Use the steps below to place the
entire system in automatic mode:
1. Press the AUTO button.
When AUTO is selected, the
display changes to show the
current temperature(s) and
AUTO is lit on the display. The
current air delivery mode and
fan speed are also displayed for
about five seconds.
When AUTO is selected, the air
conditioning operation and air
inlet are automatically controlled.
The air conditioning compressor
may run when the outside
temperature is above freezing.
The air inlet will normally be set
to outside air. If it is hot outside,
the air inlet may automatically
switch to the recirculate mode to

Black plate (7,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Climate Controls 8-7
help quickly cool down the air
inside the vehicle. The light
on the button comes on in
recirculation.
2. Set the driver and passenger temperature.
To find your comfort setting, start
with a 23°C (74°F) temperature
setting and allow about
20 minutes for the system to
regulate. Use the driver or
passenger temperature buttons
to adjust the temperature setting
as necessary. If a temperature
setting of 15°C (60°F) is chosen,
the system remains at the
maximum cooling setting. If a
temperature setting of 32°C
(90°F) is chosen, the system
remains at the maximum heat
setting. Choosing either
maximum setting will not cause
the vehicle to heat or cool any
faster.
Do not cover the solar sensor
located on the top of the instrument
panel near the windshield. This sensor regulates air temperature
based on sun load. For more
information on the solar sensor, see
“Sensors”
later in this section.
To avoid blowing cold air in cold
weather, the system delays turning
the fan on until warm air is
available. The length of delay
depends on the engine coolant
temperature. Pressing the fan
switch overrides this delay and
changes the fan to a selected
speed.
Manual Operation
D C(Fan Control): Press these
buttons to increase or decrease the
fan speed.
Pressing either fan button while in
automatic control places the fan
under manual control. The fan
setting remains displayed and the
AUTO light turns off. The air
delivery mode remains under
automatic control.
H G(Air Delivery Mode Control):
Press these buttons to change the
direction of the airflow in the vehicle.
Repeatedly press either button until
the desired mode appears on the
display.
Pressing either mode button while
the system is off changes the air
delivery mode without turning the
system on.
Pressing either mode button while
in automatic control places the
mode under manual control. The air
delivery mode setting displays and
the AUTO light turns off. The fan
remains under automatic control.
H(Vent): Air is directed to the
instrument panel outlets.
)(Bi-Level): Air is divided
between the instrument panel and
floor outlets. Some air is directed
toward the windshield and side
window outlets.

Black plate (8,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
8-8 Climate Controls
6(Floor):Air is directed to the
floor outlets, with some to the
windshield, side window outlets, and
second row floor outlets. In this
mode, the system automatically
selects outside air.
-(Defog): This mode clears the
windows of fog or moisture. Air is
directed to the windshield, floor
outlets, and side window vents. In
this mode, the system turns off
recirculation and runs the air
conditioning compressor unless the
outside temperature is close to
freezing. The recirculation mode
cannot be selected while in the
defrost mode.
0(Defrost): This mode removes
fog or frost from the windshield
more quickly. Air is directed to the
windshield and side window vents,
with some directed to the floor
vents. In this mode, the system
automatically forces outside air
into the vehicle and runs the air
conditioning compressor unless the
outside temperature is close to freezing. The recirculation mode
cannot be selected while in the
defrost mode.
The passenger temperature control
cannot be activated while in defrost
mode. If the PASS button is
pressed, the button indicator flashes
three times and will not work. If the
passenger temperature buttons are
adjusted, the driver temperature
indicator changes. The passenger
temperature will not be displayed.
If vent, bi-level, or floor mode is
selected again, the climate control
system displays the previous
temperature settings.
Do not drive the vehicle until all
windows are clear.
#(Air Conditioning):
Press to
turn the air conditioning (A/C)
compressor on and off. An indicator
light comes on to show that the air
conditioning is on.
If this button is pressed when the
air conditioning compressor is
unavailable due to outside conditions, the indicator flashes
three times and then turns off.
If the air conditioning is on and the
outside temperature drops below a
temperature which is too cool for air
conditioning to be effective, the air
conditioning light turns off to show
that the air conditioning mode has
been canceled.
On hot days, open the windows long
enough to let hot inside air escape.
This helps to reduce the time it
takes for the vehicle to cool down.
It also helps the system to operate
more efficiently.
The air conditioning system
removes moisture from the air, so a
small amount of water might drip
under the vehicle while idling or
after turning off the engine. This is
normal.
@(Recirculation):
Press to
turn the recirculation mode on. An
indicator light comes on to show
that recirculation is on.

Black plate (9,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Climate Controls 8-9
This mode recirculates and helps
to quickly cool the air inside the
vehicle. It can be used to help
prevent outside air and odors from
entering the vehicle.
The recirculation mode cannot be
used with floor, defog, or defrost
modes. If recirculation is selected
with one of those modes, the
indicator light flashes three times
and then turns off. The air
conditioning compressor also comes
on when this mode is activated.
While in recirculation mode, the
windows may fog when the weather
is cold and damp. To clear the fog,
select either the defog or defrost
mode and increase the fan speed.
The recirculation mode can be
turned off by pressing the outside
air button, or by turning off the
ignition.
;(Outside Air):Press to turn the
outside air mode on. An indicator
light on the button comes on to
show that outside is on. When
selected, air from outside the vehicle circulates throughout the
vehicle. The recirculation mode
cannot be used with the outside
air mode.
Rear Window Defogger
The rear window defogger uses a
warming grid to remove fog from the
rear window.
1(Rear Window Defogger):
For
vehicles with this feature, press
to turn the defogger on or off.
It automatically turns off several
minutes after it has been activated.
The defogger can also be turned off
by turning the engine off. Do not
drive the vehicle until all windows
are clear.
Notice: Do not use a razor blade
or sharp object to clear the inside
rear window. Do not adhere
anything to the defogger grid
lines in the rear glass. These
actions may damage the rear
defogger. Repairs would not be
covered by your warranty. Heated Mirror:
For vehicles with
heated outside rearview mirrors, the
mirrors heat to help clear fog or frost
from the surface of the mirror when
the rear window defog button is
pressed. See Power Mirrors on
page 2‑15.
Sensors
The solar sensor, located in the
defrost grille in the middle of the
instrument panel, monitors the solar
heat. Do not cover the solar sensor
or the system will not work properly.

Black plate (10,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
8-10 Climate Controls
The interior temperature sensor,
located in the headliner, measures
the temperature of the air inside the
vehicle.There is also an exterior
temperature sensor located behind
the front grille. This sensor reads
the outside air temperature and
helps maintain the temperature
inside the vehicle. Any cover on the
front of the vehicle could cause a
false reading in the displayed
temperature.
The climate control system uses the
information from these sensors to
maintain comfort settings by
adjusting the outlet temperature, fan
speed, and the air delivery mode.
The system may also supply cooler
air to the side of the vehicle facing
the sun. The recirculation mode will
also be used as needed to maintain
cool outlet temperatures.
Air Vents
Use the air outlets located in the
center and on the side of the
instrument panel to direct the
airflow. Use the thumbwheels near
the air outlets to open or close off
the airflow.
Operation Tips
.Clear away any ice, snow,
or leaves from air inlets at the
base of the windshield that could
block the flow of air into the
vehicle.
.Keep the path under the front
seats clear of objects to help
circulate the air inside of the
vehicle more effectively.
.Use of non‐GM approved hood
deflectors can adversely affect
the performance of the system.
Check with your dealer before
adding equipment to the outside
of the vehicle.

Black plate (2,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-2 Driving and Operating
Towing
General TowingInformation . . . . . . . . . . . . . . . . . 9-74
Driving Characteristics and Towing Tips . . . . . . . . . . . . . . . . 9-74
Trailer Towing . . . . . . . . . . . . . . . . 9-78
Towing Equipment . . . . . . . . . . . 9-94
Trailer Sway
Control (TSC) . . . . . . . . . . . . . 9-105
Conversions and Add-Ons
Add-On ElectricalEquipment . . . . . . . . . . . . . . . . 9-105
Adding a Snow Plow or Similar Equipment . . . . . . . . 9-106
Pickup Conversion to Chassis Cab . . . . . . . . . . . . . . 9-109
Driving Information
Distracted Driving
Distraction comes in many forms
and can take your focus from the
task of driving. Exercise good
judgment and do not let other
activities divert your attention
away from the road. Many local
governments have enacted laws
regarding driver distraction.
Become familiar with the local
laws in your area.
To avoid distracted driving, always
keep your eyes on the road, hands
on the wheel, and mind on the drive.
.Do not use a phone in
demanding driving situations.
Use a hands-free method to
place or receive necessary
phone calls.
.Watch the road. Do not
read, take notes, or look up
information on phones or other
electronic devices.
.Designate a front seat
passenger to handle potential
distractions.
.Become familiar with vehicle
features before driving, such as
programming favorite radio
stations and adjusting climate
control and seat settings.
Program all trip information into
any navigation device prior to
driving.
.Wait until the vehicle is parked
to retrieve items that have fallen
to the floor.
.Stop or park the vehicle to tend
to children.
.Keep pets in an appropriate
carrier or restraint.
.Avoid stressful conversations
while driving, whether with a
passenger or on a cell phone.

Black plate (14,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-14 Driving and Operating
Blizzard Conditions
Being stuck in snow can be a
serious situation. Stay with the
vehicle unless there is help nearby.
If possible, use theRoadside
Assistance Program (U.S. and
Canada) on page 13‑7 orRoadside
Assistance Program (Mexico) on
page 13‑9. To get help and keep
everyone in the vehicle safe:
.Turn on the hazard warning
flashers.
.Tie a red cloth to an outside
mirror.
{WARNING
Snow can trap engine exhaust
under the vehicle. This may
cause exhaust gases to get
inside. Engine exhaust contains
carbon monoxide (CO) which
cannot be seen or smelled. It can
cause unconsciousness and even
death.
(Continued)
WARNING (Continued)
If the vehicle is stuck in the snow:
.Clear away snow from around
the base of your vehicle,
especially any that is blocking
the exhaust pipe.
.Check again from time to
time to be sure snow does
not collect there.
.Open a window about 5 cm
(2 in) on the side of the
vehicle that is away from the
wind to bring in fresh air.
.Fully open the air outlets on
or under the instrument
panel.
.Adjust the climate control
system to a setting that
circulates the air inside the
vehicle and set the fan speed
to the highest setting. See
“Climate Control Systems” in
the Index.
(Continued)
WARNING (Continued)
For more information about
carbon monoxide, see Engine
Exhaust on page 9‑33.
Run the engine for short periods
only as needed to keep warm, but
be careful.
To save fuel, run the engine for only
short periods as needed to warm
the vehicle and then shut the engine
off and close the window most of
the way to save heat. Repeat this
until help arrives but only when you
feel really uncomfortable from the
cold. Moving about to keep warm
also helps.