
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 (4,1)GMC Sierra Owner Manual - 2011
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 ControlTemperature 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.

Black plate (5,1)GMC Sierra Owner Manual - 2011
Climate Controls 8-5
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.
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 (93,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-93
Passing
More passing distance is
needed when towing a trailer.
The combination will not accelerate
as quickly and is longer so it is
necessary to go much farther
beyond the passed vehicle before
returning to the lane.
Backing Up
Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand
to the left. To move the trailer to
the right, move your hand to the
right. Always back up slowly and,
if possible, have someone
guide you.
Making Turns
Notice:Making very sharp turns
while trailering could cause the
trailer to come in contact with
the vehicle. The vehicle could be
damaged. Avoid making very
sharp turns while trailering.
When turning with a trailer,
make wider turns than normal.
Do this so the trailer will not strike
soft shoulders, curbs, road signs,
trees, or other objects. Avoid jerky
or sudden maneuvers. Signal well
in advance.
If the trailer turn signal bulbs burn
out, the arrows on the instrument
panel will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Driving on Grades
Reduce speed and shift to a
lower gear beforestarting down
a long or steep downgrade. If the
transmission is not shifted down,
the brakes might get hot and no
longer work well.
Vehicles can tow in D (Drive).
Shift the transmission to a lower
gear if the transmission shifts too
often under heavy loads and/or
hilly conditions.
The Tow/Haul Mode may be used
if the transmission shifts too often.
See Tow/Haul Mode on page 9‑51.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil
at a lower temperature than at
normal altitudes. If the engine is
turned off immediately after towing
at high altitude on steep uphill
grades, the vehicle may show
signs similar to engine overheating.

Black plate (94,1)GMC Sierra Owner Manual - 2011
9-94 Driving and Operating
To avoid this, let the engine
run while parked, preferably on
level ground, with the automatic
transmission in P (Park) for a few
minutes before turning the engine
off. If the overheat warning comes
on, seeEngine Overheating on
page 10‑25.
Parking on Hills
{WARNING
Parking the vehicle on a hill
with the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface. If parking the rig on a hill:
1. Press the brake pedal, but
do not shift into P (Park) yet.
Turn the wheels into the curb if
facing downhill or into traffic if
facing uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the regular brakes
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park).
5. If the vehicle is four-wheel-drive, be sure the transfer case is in a
drive gear and not in N (Neutral).
6. Release the brake pedal.
{WARNING
It can be dangerous to get out of
the vehicle if the shift lever is not
fully in P (Park) with the parking
brake firmly set. The vehicle
can roll.
If the engine has been left
running, the vehicle can move
suddenly. You or others could be
injured. To be sure the vehicle will
not move, even when on fairly
level ground, use the steps that
follow.
Always put the shift lever fully in
P (Park) with the parking brake
firmly set.
If the transfer case on a
four-wheel-drive vehicle is in
N (Neutral), the vehicle will be
free to roll, even if the shift lever
is in P (Park). Be sure the transfer
case is in a drive gear —not in
N (Neutral).

Black plate (1,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-3
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-4
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil . . . . . . . . . . . . . . . . . . . 10-7
Engine Oil Life System . . . . . 10-11
Automatic Transmission Fluid (4-Speed
Transmission) . . . . . . . . . . . . . 10-13
Automatic Transmission Fluid (6-Speed
Transmission) . . . . . . . . . . . . . 10-16
Engine Air Cleaner/Filter . . . . 10-19
Cooling System . . . . . . . . . . . . 10-20
Engine Coolant . . . . . . . . . . . . . 10-22 Engine Overheating . . . . . . . . 10-25
Overheated Engine
Protection
Operating Mode . . . . . . . . . . . 10-28
Engine Fan . . . . . . . . . . . . . . . . . 10-28
Power Steering Fluid . . . . . . . 10-29
Washer Fluid . . . . . . . . . . . . . . . 10-29
Brakes . . . . . . . . . . . . . . . . . . . . . 10-30
Brake Fluid . . . . . . . . . . . . . . . . . 10-32
Battery . . . . . . . . . . . . . . . . . . . . . 10-34
Four-Wheel Drive . . . . . . . . . . . 10-34
Front Axle . . . . . . . . . . . . . . . . . . 10-36
Rear Axle . . . . . . . . . . . . . . . . . . 10-37
Noise Control System . . . . . . 10-38
Starter Switch Check . . . . . . . 10-39
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-40
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-40
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-40
Wiper Blade Replacement . . . . . . . . . . . . . . 10-41
Glass Replacement . . . . . . . . 10-41
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-42
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-44
Halogen Bulbs . . . . . . . . . . . . . . 10-44
Headlamps . . . . . . . . . . . . . . . . . 10-44
Pick-Up Box Identification and Fender Marker
Lamps . . . . . . . . . . . . . . . . . . . . 10-45
Taillamps (Chassis Cab Models) . . . . . . . . . . . . . . . . . . . 10-46
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-46
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . 10-47
License Plate Lamp . . . . . . . . 10-48
Replacement Bulbs . . . . . . . . . 10-48
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-49
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-50
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-50
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-54

Black plate (22,1)GMC Sierra Owner Manual - 2011
10-22 Vehicle Care
Engine Coolant
The cooling system in the vehicle
is filled with DEX-COOL®engine
coolant. This coolant is designed to
remain in the vehicle for 5 years or
240 000 km (150,000 mi), whichever
occurs first.
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating,
see Engine Overheating on
page 10‑25.
What to Use
{WARNING
Adding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water
and other liquids, can boil before
the proper coolant mixture will.
The coolant warning system is
set for the proper coolant mixture.
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
overheat warning. The engine
could catch fire and you or
others could be burned. Use a
50/50 mixture of clean, drinkable
water and DEX-COOL coolant. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. If using this mixture,
nothing else needs to be added.
This mixture:.Gives freezing protection down
to
−37°C (−34°F), outside
temperature
.Gives boiling protection
up to 129°C (265°F), engine
temperature
.Protects against rust and
corrosion
.Will not damage aluminum parts
.Helps keep the proper engine
temperature
Notice: If an improper coolant
mixture is used, the engine could
overheat and be badly damaged.
The repair cost would not be
covered by the vehicle warranty.
Too much water in the mixture
can freeze and crack the engine,
radiator, heater core, and other
parts.

Black plate (25,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-25
3. Fill the coolant surge tankwith the proper mixture to the
FULL COLD mark.
4. With the coolant surge tank pressure cap off, start the
engine and let it run until the
engine coolant temperature
gauge indicates approximately
90°C (195°F). By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
lower, add more of the proper
mixture to the coolant surge
tank until the level reaches the
FULL COLD mark.
5. Replace the pressure cap. Be sure the pressure cap is
hand-tight and fully seated.
6. Verify coolant level after the engine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1 through 6.
Notice: If the pressure cap is
not tightly installed, coolant loss
and possible engine damage may
occur. Be sure the cap is properly
and tightly secured.
Engine Overheating
If the vehicle has the Duramax®
Diesel engine, see the Duramax
Diesel Supplement for more
information.
The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge on the vehicle's instrument
panel. See Engine Coolant
Temperature Gauge on page 5‑17.
In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC) on the
instrument panel. See Engine
Cooling System Messages on
page 5‑44 andEngine Power
Messages on page 5‑45.