Page 317 of 594

Black plate (23,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-23
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.
If it takes some time for help to
arrive, now and then when you run
the engine, push the accelerator
pedal slightly so the engine runs
faster than the idle speed. This
keeps the battery charged to restart
the vehicle and to signal for help
with the headlamps. Do this as little
as possible to save fuel.If the Vehicle is Stuck
Slowly and cautiously spin the
wheels to free the vehicle when
stuck in sand, mud, ice, or snow.
See“Rocking Your Vehicle to Get
It Out” later in this section.
If the vehicle has a traction system,
it can often help to free a stuck
vehicle. Refer to the vehicle's
traction system in the Index. If stuck
too severely for the traction system
to free the vehicle, turn the traction
system off and use the rocking
method.{WARNING
If the vehicle's tires spin at high
speed, they can explode, and
you or others could be injured.
The vehicle can overheat,
causing an engine compartment
fire or other damage. Spin the
wheels as little as possible and
avoid going above 55 km/h
(35 mph).
For information about using tire
chains on the vehicle, see Tire
Chains on page 10‑83.
Page 318 of 594

Black plate (24,1)GMC Sierra Owner Manual - 2011
9-24 Driving and Operating
Rocking Your Vehicle to Get
It Out
Turn the steering wheel left and
right to clear the area around the
front wheels. For four-wheel-drive
vehicles, shift into Four‐Wheel
High. For vehicles with StabiliTrak
®,
turn the traction control part of the
system off. Shift back and forth
between R (Reverse) and a forward
gear, spinning the wheels as little as
possible. To prevent transmission
wear, wait until the wheels stop
spinning before shifting gears.
Release the accelerator pedal
while shifting, and press lightly
on the accelerator pedal when
the transmission is in gear. Slowly
spinning the wheels in the forward
and reverse directions causes a
rocking motion that could free the vehicle. If that does not get the
vehicle out after a few tries, it might
need to be towed out. Recovery
hooks can be used, if the vehicle
has them. If the vehicle does need
to be towed out, see
Towing the
Vehicle on page 10‑103.
Recovery Hooks
{WARNING
These hooks, when used, are
under a lot of force. Always pull
the vehicle straight out. Never pull
on the hooks at a sideways angle.
The hooks could break off and
you or others could be injured
from the chain or cable
snapping back.Notice: Never use recovery
hooks to tow the vehicle.
Your vehicle could be damaged
and it would not be covered by
warranty.
For vehicles with recovery hooks at
the front of the vehicle, you can use
them if you are stuck off-road and
need to be pulled to some place
where you can continue driving.
Page 331 of 594

Black plate (37,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-37
C (ON/RUN):This position can
be used to operate the electrical
accessories and to display some
instrument panel cluster warning
and indicator lights. The switch
stays in this position when the
engine is running. The transmission
is also unlocked in this position on
automatic transmission vehicles.
If you leave the key in the
ACC/ACCESSORY or ON/RUN
position with the engine off, the
battery could be drained. You may
not be able to start the vehicle if the
battery is allowed to drain for an
extended period of time.
D (START): This is the position that
starts the engine. When the engine
starts, release the key. The ignition
switch returns to ON/RUN for
driving.
A warning tone will sound when
the driver door is opened and the
ignition is in ACC/ACCESSORY or
LOCK/OFF, and the key is in the
ignition.Starting the Engine
If the vehicle has a Duramax diesel
engine, see the Duramax diesel
supplement for more information.
If the vehicle is a hybrid, see
the hybrid supplement for more
information.
Notice: Do not try to shift to
P (Park) if the vehicle is moving.
If you do, you could damage the
transmission. Shift to P (Park)
only when the vehicle is stopped.
Move the shift lever to P (Park) or
N (Neutral). The engine will not start
in any other position. To restart the
engine when the vehicle is already
moving, use N (Neutral) only.
Notice: The engine is designed to
work with the electronics in the
vehicle. If you add electrical parts
or accessories, you could change
the way the engine operates. Before adding electrical
equipment, check with your
dealer. If you do not, the engine
might not perform properly.
Any resulting damage would
not be covered by the vehicle
warranty.
Starting Procedure
1. With your foot off the accelerator
pedal, turn the ignition key to
START. When the engine starts,
let go of the key. The idle speed
will go down as your engine gets
warm. Do not race the engine
immediately after starting it.
Operate the engine and
transmission gently to allow
the oil to warm up and lubricate
all moving parts.
Page 340 of 594

Black plate (46,1)GMC Sierra Owner Manual - 2011
9-46 Driving and Operating
Automatic
Transmission
If the vehicle is a hybrid, see
the hybrid supplement for more
information.
Vehicles with an automatic
transmission have an electronic
shift position indicator within
the instrument panel cluster.
This display comes on when
the ignition key is turned to
the ON/RUN position.There are several different positions
for the shift lever.
Hydra-Matic®4-Speed Automatic
Transmission
Heavy Duty 6-Speed
Automatic Transmission Shown (Light Duty 6‐Speed Similar)
See “Range Selection Mode” under
Manual Mode on page 9‑50. P (Park):
This position locks the
rear wheels. It is the best position
to use when starting the engine
because the vehicle cannot move
easily. When parked on a hill,
especially when the vehicle has a
heavy load, you might notice an
increase in the effort to shift out of
P (Park). See “Torque Lock” under
Shifting Into Park on page 9‑41 for
more information.
{WARNING
It is 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.
Do not leave the vehicle when
the engine is running unless
you have to. If you have left the
engine running, the vehicle can
move suddenly. You or others
(Continued)
Page 345 of 594

Black plate (51,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-51
Low Traction Mode
If your vehicle has the Allison
Transmission, or the Hydra-Matic
6-Speed Automatic Transmission,
it has a Low Traction Mode that
can assist in vehicle acceleration
when road conditions are slippery,
such as with ice or snow. While
the vehicle is at a stop, select the
second gear range using Range
Selection Mode. This will limit
torque to the wheels after it detects
wheel slip, preventing the tires from
spinning.
Tow/Haul Mode
Vehicles with an automatic
transmission have a Tow/Haul
Mode. The Tow/Haul Mode adjusts
the transmission shift pattern to
reduce shift cycling, providing
increased performance, vehicle
control, and transmission cooling
when towing or hauling heavy loads.The selector button is located on
the end of the shift lever. Turn
the Tow/Haul Mode on and off
by pressing the button. When
the tow/haul is on, a light on the
instrument panel cluster will
come on.
See
Tow/Haul Mode Light on
page 5‑29 for more information.
Also see “Tow/Haul Mode” under
Towing Equipment on page 9‑112
for more information.
Page 346 of 594

Black plate (52,1)GMC Sierra Owner Manual - 2011
9-52 Driving and Operating
Tow/Haul Mode
(Allison Transmission
or Hydra-Matic 6-Speed
Automatic Transmission)
Vehicles with an Allison
Transmission or Hydra-Matic
6-Speed Automatic Transmission
have a Tow/Haul Mode. The Tow/
Haul Mode adjusts the transmission
shift pattern to reduce shift cycling,
providing increased performance,
vehicle control, and transmission
cooling when towing or hauling
heavy loads.Turn the Tow/Haul Mode on and
off by pressing the button, located
on the end of the shift lever. When
the tow/haul is on, a light on the
instrument panel cluster will
come on.
See
Tow/Haul Mode Light on
page 5‑29 for more information.
Also see “Tow/Haul Mode” under
Towing Equipment on page 9‑112
for more information.
Grade Braking
(Allison Transmission
or Hydra-Matic 6-Speed
Automatic Transmission)
The Grade Braking shift modes
can be activated by pressing the
button on the end of the shift control
lever. While in Range Selection
Mode, Grade Braking is deactivated
allowing the driver to select a
desired range of gears.
Grade Braking is only active while
the Tow/Haul Mode is selected and
you are not in the Range Selection
Mode. See “Tow/Haul Mode” listed
previously and Manual Mode on
page 9‑50 for more information
on the Range Selection Mode.
Page 349 of 594

Black plate (55,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-55
A Four-Wheel Drive indicator light
comes on when you shift into
four-wheel drive and the front axle
engages. SeeFour-Wheel-Drive
Light on page 5‑29.
Some delay between shifting and
when the indicator light comes on is
normal.
Recommended Transfer Case Settings
Driving Conditions Transfer Case Settings
2m 4m4n N
Normal YES Severe YES
Extreme YES
Vehicle in Tow* YES
*See Recreational Vehicle Towing on page 10‑103 orTowing the Vehicle
on page 10‑103.
Notice: Driving on clean, dry
pavement in four-wheel drive for
an extended period of time can
cause premature wear on the
vehicle's powertrain. Do not
drive on clean, dry pavement in
Four-Wheel Drive for extended
periods of time. 4
n(Four-Wheel Drive Low):
This
setting also engages the front axle
and delivers extra torque. You may
never need Four-Wheel Drive Low.
It sends maximum power to all
four wheels. You might choose
Four-Wheel Drive Low if you are
driving off-road in deep sand,
deep mud, deep snow, and while
climbing or descending steep hills.
Page 352 of 594

Black plate (58,1)GMC Sierra Owner Manual - 2011
9-58 Driving and Operating
Shifting In or Out of Four-Wheel
Drive Low
Notice:Shifting the transfer
case into Four-Wheel-Drive Low
while moving at speeds faster
than 5 km/h (3 mph) may cause
premature wear to the transfer
case, and may cause the gears
to grind. To avoid causing
premature wear, and grinding the
gears, do not shift the transfer
case into Four-Wheel-Drive Low
while the vehicle is moving faster
than 5 km/h (3 mph).
.Shifting into Four-Wheel Drive
Low should be done, if possible,
with the vehicle at a slight roll,
5 km/h (3 mph) or less.
.Shift the transmission into
N (Neutral).
{WARNING
Shifting the transfer case to
N (Neutral) can cause the vehicle
to roll even if the transmission
is in P (Park). You or someone
else could be seriously injured.
Be sure to set the parking brake
before placing the transfer case in
N (Neutral). See Parking Brake on
page 9‑69.
.Shifting into Four-Wheel Drive
Low with the vehicle at a stop
may be more difficult. You may
be unable to complete the shift
to Four-Wheel Drive Low, and
the transfer case will end up in
N (Neutral). This is normal, and
is a function of the gear teeth
aligning in the transfer case.
When this happens, make
sure the engine is on, shift
the transmission momentarily
to D (Drive) and back to
N (Neutral), and then complete
the transfer case shift.
.Shift the transfer case shift lever
in one continuous motion into
the Four-Wheel Drive Low
position.
.When in Four-Wheel Drive
Low do not drive faster than
72 km/h (45 mph). This will
reduce wear and extend the
life of your transfer case.
Shifting In or Out of Neutral
1. With the vehicle running and the engine at an idle, set the parking
brake.
2. Place the transmission into N (Neutral).
Shift the transfer case in one
continuous motion into or out of the
N (Neutral) position.