2012 GMC SIERRA 1500 climate control

Black plate (39,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Instruments and Controls 5-39
Remember, you must reset the OIL
LIFE display after each oil change.
It will not reset itself. Also, be
careful not to reset the OIL LIFE
display accidentally at any time
other than when the oil has just
been changed. It cannot be reset
accurately until the next oil change.
To reset the engine oil life system,
seeEngine Oil Life System on
page 10‑10.Vehicle Messages
Messages displayed on the DIC
indicate the status of the vehicle or
some action may be needed to
correct a condition. Multiple
messages may appear one after
another.
The messages that do not
require immediate action can be
acknowledged and cleared by
pressing
V(Set/Reset) or the trip
odometer reset stem.
The messages that require
immediate action cannot be cleared
until that action is performed.
All messages should be taken
seriously and clearing the message
does not correct the problem.
The following are the possible
messages and some information
about them. If the vehicle has a diesel
engine, see the Duramax
®diesel
supplement for more information.
Battery Voltage and
Charging Messages
BATTERY LOW START
VEHICLE
When the vehicle’ s battery is
severely discharged, this message
will display and four chimes
will sound. Start the vehicle
immediately. If the vehicle is not
started and the battery continues to
discharge, the climate controls,
heated seats, and audio systems
will shut off and the vehicle may
require a jump start. These systems
will function again after the vehicle
is started.

Black plate (9,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Lighting 6-9
Lighting Features
Entry Lighting
The vehicle has an illuminated entry
feature.
When the doors are opened, the
dome lamps will come on if the
dome override button is in the
extended position. If the dome
override button is pressed in, the
lamps will not come on.
Exit Lighting
The interior lamps come on when
the key is removed from the ignition.
They turn off automatically in
20 seconds. The lights do not come
on if the dome override button is
pressed in.
Battery Load
Management
The vehicle has Electric Power
Management (EPM) that estimates
the battery's temperature and state
of charge. It then adjusts the voltage
for best performance and extended
life of the battery.
When the battery's state of charge
is low, the voltage is raised slightly
to quickly bring the charge back up.
When the state of charge is high,
the voltage is lowered slightly to
prevent overcharging. If the vehicle
has a voltmeter gauge or a voltage
display on the Driver Information
Center (DIC), you may see the
voltage move up or down. This is
normal. If there is a problem, an
alert will be displayed.The battery can be discharged at
idle if the electrical loads are very
high. This is true for all vehicles.
This is because the generator
(alternator) may not be spinning fast
enough at idle to produce all of
the power needed for very high
electrical loads.
A high electrical load occurs when
several of the following are on, such
as: headlamps, high beams, fog
lamps, rear window defogger,
climate control fan at high speed,
heated seats, engine cooling fans,
trailer loads, and loads plugged into
accessory power outlets.
EPM works to prevent excessive
discharge of the battery. It does this
by balancing the generator's output
and the vehicle's electrical needs.
It can increase engine idle speed to
generate more power whenever
needed. It can temporarily reduce
the power demands of some
accessories.

Black plate (1,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Climate Controls 8-1
Climate Controls
Climate Control Systems
Climate Control Systems (withAir Conditioning) . . . . . . . . . . . . . 8-1
Climate Control Systems (with Heater Only) . . . . . . . . . . . . . . . . . 8-4
Dual Automatic Climate Control System . . . . . . . . . . . . . . . . . . . . . . 8-5
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . 8-10
Climate Control Systems
Climate Control Systems (with Air Conditioning)
With this system the heating, cooling, and ventilation can be controlled.
A. Fan Control
B. Temperature Control
C. Air Delivery Mode Control
D. Air Conditioning
E. Outside Air
F. Recirculation
G. Rear Window Defogger 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.

Black plate (2,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
8-2 Climate Controls
Air Delivery Mode Control:Turn
clockwise or counterclockwise to
change the direction of the airflow
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 and side window
outlets. In this mode, the system
automatically selects outside air.
Recirculation cannot be selected in
floor mode.
-(Defog): This mode clears the
windows of fog or moisture. Air is
directed to the windshield, floor
outlets, and side window vents.
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.
The recirculation mode cannot be
selected in the defog or defrost
mode. When either mode is
selected, the system runs the air
conditioning compressor, unless
the outside temperature is close to
freezing.
Do not drive the vehicle until all the
windows are clear.
:(Outside Air): Press to turn
the outside air mode on. An
indicator light comes on to show
that outside air is on. In this mode
outside air circulates throughout
the vehicle. The outside air mode
can be used with all modes,
but it cannot be used with the
recirculation mode.
?(Recirculation): Press to turn
the recirculation mode on. An
indicator light comes on to show
that recirculation is on.
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 these modes, the
indicator light flashes three times
and then turns off. 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.

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