2011 GMC SIERRA air condition

Black plate (25,1)GMC Sierra Owner Manual - 2011
Instruments and Controls 5-25
Malfunction
Indicator Lamp
A computer system called OBD II
(On-Board Diagnostics-Second
Generation) monitors operation of
the fuel, ignition, and emission
control systems. It ensures that
emissions are at acceptable levels
for the life of the vehicle, helping to
produce a cleaner environment.
This light should come on when the
ignition is on, but the engine is not
running, as a check to show it is
working. If it does not, have the
vehicle serviced by your dealer.If the Malfunction Indicator Lamp
comes on and stays on while the
engine is running, this indicates
that there is an OBD II problem
and service is required.
Malfunctions often are indicated by
the system before any problem is
apparent. Being aware of the light
can prevent more serious damage
to the vehicle. This system assists
the service technician in correctly
diagnosing any malfunction.
Notice:
If the vehicle is
continually driven with this light
on, after a while, the emission
controls might not work as well,
the vehicle fuel economy might
not be as good, and the engine
might not run as smoothly.
This could lead to costly repairs
that might not be covered by the
vehicle warranty. Notice:
Modifications made
to the engine, transmission,
exhaust, intake, or fuel system
of the vehicle or the replacement
of the original tires with
other than those of the same
Tire Performance Criteria (TPC)
can affect the vehicle's emission
controls and can cause this light
to come on. Modifications to
these systems could lead to
costly repairs not covered by
the vehicle warranty. This could
also result in a failure to
pass a required Emission
Inspection/Maintenance
test. See Accessories and
Modifications on page 10‑3.
This light comes on during a
malfunction in one of two ways:
Light Flashing: A misfire condition
has been detected. A misfire
increases vehicle emissions and
could damage the emission control
system on the vehicle. Diagnosis
and service might be required.

Black plate (44,1)GMC Sierra Owner Manual - 2011
5-44 Instruments and Controls
Engine Cooling System
Messages
ENGINE HOT A/C
(Air Conditioning)
TURNED OFF
This message displays when the
engine coolant becomes hotter than
the normal operating temperature.
SeeEngine Coolant Temperature
Gauge on page 5‑17. To avoid
added strain on a hot engine,
the air conditioning compressor
automatically turns off. When
the coolant temperature returns
to normal, the air conditioning
compressor turns back on.
You can continue to drive
your vehicle.
If this message continues to appear,
have the system repaired by your
dealer as soon as possible to avoid
damage to the engine.
ENGINE OVERHEATED IDLE
ENGINE
Notice: If you drive the vehicle
while the engine is overheating,
severe engine damage may
occur. If an overheat warning
appears on the instrument panel
cluster and/or DIC, stop the
vehicle as soon as possible.
See Engine Overheating on
page 10‑25 for more information.
This message displays when the
engine coolant temperature is too
hot. Stop and allow the vehicle to
idle until it cools down. See Engine
Coolant Temperature Gauge on
page 5‑17.
See Overheated Engine Protection
Operating Mode on page 10‑28 for
information on driving to a safe
place in an emergency.
ENGINE OVERHEATED STOP
ENGINE
Notice: If you drive the vehicle
while the engine is overheating,
severe engine damage may
occur. If an overheat warning
appears on the instrument panel
cluster and/or DIC, stop the
vehicle as soon as possible.
See Engine Overheating on
page 10‑25 for more information.
This message displays and a
chime may sound if the engine
cooling system reaches unsafe
temperatures for operation. Stop
and turn off the vehicle as soon as
it is safe to do so to avoid severe
damage. This message clears when
the engine has cooled to a safe
operating temperature.

Black plate (48,1)GMC Sierra Owner Manual - 2011
5-48 Instruments and Controls
There are several conditions that
can cause this message to appear.
.If the vehicle is overheating,
which could occur if StabiliTrak
activates continuously for an
extended period of time.
.If the brake system warning
light is on. SeeBrake System
Warning Light on page 5‑27.
.If the stability system takes
longer than usual to complete its
diagnostic checks due to driving
conditions.
.If an engine or vehicle related
problem has been detected
and the vehicle needs service.
See your dealer.
.If the vehicle is shifted into 4LO.
The message turns off as soon
as the conditions that caused the
message to be displayed are no
longer present.
TRACTION CONTROL OFF
If the vehicle has StabiliTrak, this
message displays when the Traction
Control System (TCS) is turned off.
Adjust your driving accordingly. See
StabiliTrak
®System on page 9‑70
for more information.
Airbag System Messages
SERVICE AIR BAG
This message displays if there is
a problem with the airbag system.
Have your dealer inspect the
system for problems. See Airbag
Readiness Light on page 5‑20 and
Airbag System on page 3‑29 for
more information.
Anti-Theft Alarm System
Messages
SERVICE THEFT DETERRENT
SYSTEM
This message displays when there
is a problem with the theft-deterrent
system. The vehicle may or may not
restart so you may want to take the
vehicle to your dealer before turning
off the engine. See Immobilizer
Operation on page 2‑13 for more
information.
Starting the Vehicle
Messages
FAST IDLE ON
If your vehicle has this feature, this
message displays when the fast idle
feature is on. See Fast Idle System
on page 9‑39 for more information.

Black plate (49,1)GMC Sierra Owner Manual - 2011
Instruments and Controls 5-49
Tire Messages
SERVICE TIRE MONITOR
SYSTEM
If the vehicle has the Tire Pressure
Monitor System (TPMS), this
message displays if a part on the
system is not working properly.
The tire pressure light also flashes
and then remains on during the
same ignition cycle. SeeTire
Pressure Light on page 5‑30.
Several conditions may cause
this message to appear. See Tire
Pressure Monitor Operation on
page 10‑69 for more information.
If the warning comes on and stays
on, there may be a problem with
the TPMS. See your dealer.
TIRE LEARNING ACTIVE
If the vehicle has the Tire Pressure
Monitor System (TPMS), this
message displays when the system
is re-learning the tire positions on
your vehicle. The tire positions must
be re-learned after rotating the tires
or after replacing a tire or sensor.
See Tire Inspection on page 10‑73,
Tire Rotation on page 10‑73,
Tire Pressure Monitor System on
page 10‑68, and Tire Pressure on
page 10‑66 for more information.
TIRE LOW ADD AIR TO TIRE
If the vehicle has the Tire Pressure
Monitor System (TPMS), this
message displays when the
pressure in one or more of the
vehicle's tires is low. This message
also displays LEFT FRT (left front),
RIGHT FRT (right front), LEFT RR (left rear), or RIGHT RR (right rear)
to indicate the location of the low
tire. The low tire pressure warning
light will also come on. See
Tire
Pressure Light on page 5‑30.
You can receive more than one
tire pressure message at a time.
To read the other messages that
may have been sent at the same
time, press the set/reset button or
the trip odometer reset stem. If a
tire pressure message appears on
the DIC, stop as soon as you can.
Have the tire pressures checked
and set to those shown on the Tire
Loading Information label. See Tires
on page 10‑57, Vehicle Load Limits
on page 9‑25, and Tire Pressure on
page 10‑66. The DIC also shows
the tire pressure values. See Driver
Information Center (DIC) on
page 5‑33.

Black plate (50,1)GMC Sierra Owner Manual - 2011
5-50 Instruments and Controls
Transmission Messages
SERVICE 4 WHEEL DRIVE
If the vehicle has four-wheel
drive, this message may display
if a problem occurs with the
four-wheel-drive system. If this
message appears, stop as soon
as possible and turn off the vehicle.
Make sure the key is in the
LOCK/OFF position for at least
one minute and then restart the
vehicle and check for the message
on the DIC display. If the message
is still displayed or appears again
when you begin driving, the
four-wheel-drive system needs
service. See your dealer.
TRANSMISSION HOT IDLE
ENGINE
Notice:If you drive the vehicle
while the transmission fluid is
overheating and the transmission
temperature warning is displayed
on the instrument panel cluster
and/or DIC, you can damage the
transmission. This could lead to
costly repairs that would not be
covered by the warranty. Do not
drive the vehicle with overheated
transmission fluid or while the
transmission temperature
warning is displayed.
This message displays and a chime
may sound if the transmission fluid
in the vehicle gets hot. Driving with
the transmission fluid temperature
high can cause damage to the
vehicle. Stop the vehicle and let it
idle to allow the transmission to
cool. This message clears and
the chime stops when the fluid
temperature reaches a safe level.
Vehicle Reminder
Messages
CHECK TRAILER WIRING
On vehicles with the Integrated
Trailer Brake Control (ITBC) system,
this message may display and a
chime may sound when one of the
following conditions exists:
.A trailer with electric brakes
becomes disconnected from the
vehicle.
‐ If the disconnect occurs while
the vehicle is stopped, this
message clears itself after a
short time.
‐ If the disconnect occurs while
the vehicle is moving, this
message stays on until the
ignition is turned off.
.There is a short in the wiring to
the electric trailer brakes.

Black plate (1,1)GMC Sierra Owner Manual - 2011
Climate Controls 8-1
Climate Controls
Climate Control Systems
Climate Control Systems(with Air Conditioning) . . . . . . . 8-1
Climate Control Systems (with Heater Only) . . . . . . . . . . . 8-4
Dual Automatic Climate Control System . . . . . . . . . . . . . . . . . . . . . . 8-5
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . 8-11
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

Black plate (2,1)GMC Sierra Owner Manual - 2011
8-2 Climate Controls
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
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.

Black plate (3,1)GMC Sierra Owner Manual - 2011
Climate Controls 8-3
?(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.#(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.
<(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.