2011 GMC SIERRA transmission

Black plate (15,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-15
Driving Downhill
When off-roading takes you
downhill, consider:
.How steep is the downhill? Will I
be able to maintain vehicle
control?
.What is the surface like?
Smooth? Rough? Slippery?
Hard-packed dirt? Gravel?
.Are there hidden surface
obstacles? Ruts? Logs?
Boulders?
.What is at the bottom of the hill?
Is there a hidden creek bank or
even a river bottom with large
rocks?
If you decide you can go down
a hill safely, try to keep the vehicle
headed straight down. Use a low
gear so engine drag can help the
brakes so they do not have to do all
the work. Descend slowly, keeping
the vehicle under control at all
times.
{WARNING
Heavy braking when going
down a hill can cause your
brakes to overheat and fade.
This could cause loss of control
and a serious accident. Apply the
brakes lightly when descending a
hill and use a low gear to keep
vehicle speed under control.
Things not to do when driving down
a hill:
.When driving downhill, avoid
turns that take you across the
incline of the hill. A hill that is
not too steep to drive down
might be too steep to drive
across. The vehicle could
roll over.
.Never go downhill with the
transmission in N (Neutral),
called free-wheeling. The brakes
will have to do all the work and
could overheat and fade.
Vehicles are much more likely to
stall when going uphill, but if it
happens when going downhill:
1. Stop the vehicle by applying the regular brakes and apply the
parking brake.
2. Shift to P (Park) and, while still braking, restart the engine.
3. Shift back to a low gear, release the parking brake, and drive
straight down.
4. If the engine will not start, get out and get help.

Black plate (20,1)GMC Sierra Owner Manual - 2011
9-20 Driving and Operating
Other Rainy Weather Tips
Besides slowing down, other wet
weather driving tips include:
.Allow extra following distance.
.Pass with caution.
.Keep windshield wiping
equipment in good shape.
.Keep the windshield washer fluid
reservoir filled.
.Have good tires with proper
tread depth. SeeTires on
page 10‑57.
.Turn off cruise control.
Highway Hypnosis
Always be alert and pay attention
to your surroundings while driving.
If you become tired or sleepy, find
a safe place to park the vehicle
and rest.
Other driving tips include:
.Keep the vehicle well ventilated.
.Keep interior temperature cool.
.Keep your eyes moving —scan
the road ahead and to the sides.
.Check the rearview mirror and
vehicle instruments often.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips for
driving in these conditions include:
.Keep the vehicle serviced and in
good shape.
.Check all fluid levels and brakes,
tires, cooling system, and
transmission.
.Shift to a lower gear when going
down steep or long hills.
{WARNING
If you do not shift down, the
brakes could get so hot that they
would not work well. You would
then have poor braking or even
none going down a hill. You could
crash. Shift down to let the engine
assist the brakes on a steep
downhill slope.

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.

Black plate (36,1)GMC Sierra Owner Manual - 2011
9-36 Driving and Operating
A (STOPPING THE ENGINE/
LOCK/OFF):When the vehicle is
stopped, turn the ignition switch to
LOCK/OFF to turn the engine off.
Retained Accessory Power (RAP)
will remain active. See Retained
Accessory Power (RAP) on
page 9‑40.
This position locks the ignition.
It also locks the transmission on
automatic transmission vehicles.
The key can be removed in
LOCK/OFF.
Do not turn the engine off when the
vehicle is moving. This will cause a
loss of power assist in the brake
and steering systems and disable
the airbags. In an emergency:
1. Brake using a firm and steady
pressure. Do not pump the
brakes repeatedly. This may
deplete power assist, requiring
increased brake pedal force.
2. Shift the vehicle to neutral. This can be done while the vehicle is
moving. After shifting to neutral,
firmly apply the brakes and steer
the vehicle to a safe location.
3. Come to a complete stop, shift to P (Park), and turn the ignition
to LOCK/OFF. On vehicles with
an automatic transmission, the
shift lever must be in P (Park)
to turn the ignition switch to the
LOCK/OFF position.
4. Set the parking brake. See Parking Brake on page 9‑69. The steering can bind with the
wheels turned off center. If this
happens, move the steering wheel
from right to left while turning the
key to ACC/ACCESSORY. If this
doesn't work, then the vehicle
needs service.
Notice:
Using a tool to force the
key to turn in the ignition could
cause damage to the switch or
break the key. Use the correct
key, make sure it is all the way in,
and turn it only with your hand.
If the key cannot be turned by
hand, see your dealer.
B (ACC/ACCESSORY): This
position lets things like the radio
and the windshield wipers operate
while the engine is off. Use this
position if the vehicle must be
pushed or towed.

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.

Black plate (38,1)GMC Sierra Owner Manual - 2011
9-38 Driving and Operating
The vehicle has a
Computer-Controlled
Cranking System. This feature
assists in starting the engine
and protects components.
If the ignition key is turned
to the START position, and
then released when the engine
begins cranking, the engine
will continue cranking for a
few seconds or until the vehicle
starts. If the engine does not
start and the key is held in
START for many seconds,
cranking will be stopped after
15 seconds to prevent cranking
motor damage. To prevent
gear damage, this system also
prevents cranking if the engine
is already running. Engine
cranking can be stopped by
turning the ignition switch to
the ACC/ACCESSORY or
LOCK/OFF position.When the Low Fuel warning
lamp is on and the FUEL LEVEL
LOW message is displayed in
the Driver Information Center
(DIC), the Computer‐Controlled
Cranking System is disabled
to prevent possible vehicle
component damage. When
this happens, hold the ignition
switch in the START position
to continue engine cranking.
Notice: Cranking the engine for
long periods of time, by returning
the key to the START position
immediately after cranking has
ended, can overheat and damage
the cranking motor, and drain the
battery. Wait at least 15 seconds
between each try, to let the
cranking motor cool down. 2. If the engine does not start
after 5‐10 seconds, especially
in very cold weather (below
−18°C or 0°F), it could be
flooded with too much gasoline.
Try pushing the accelerator
pedal all the way to the floor
and holding it there as you
hold the key in START for up
to 15 seconds. Wait at least
15 seconds between each try, to
allow the cranking motor to cool
down. When the engine starts,
let go of the key and accelerator.
If the vehicle starts briefly but
then stops again, do the same
thing. This clears the extra
gasoline from the engine. Do not
race the engine immediately
after starting it. Operate the
engine and transmission gently
until the oil warms up and
lubricates all moving parts.

Black plate (39,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-39
Fast Idle System
If the vehicle has this feature it is
available only with cruise control.
The manual fast idle switch is
operated using the cruise control
buttons located on the left hand
side of the steering wheel.
This system can be used to
increase engine idle speed
whenever the following conditions
are met:
.The park brake is set.
.The brake pedal is not pressed.
.The vehicle must not be moving
and the accelerator must not be
pressed.To control the fast idle:
.To enable the Fast Idle System,
press and release the Cruise
Control On/Off button and
ensure that the switch LED is lit.
.Press and release the Cruise
Control Set switch. Engine
speed will be held at
approximately 1200 RPM.
When the fast idle is active the
Driver Information Center (DIC) will
display “FAST IDLE ON.”
One of the following actions will turn
off the fast idle:
.Pressing the brake.
.Selecting the Cruise Control
Cancel button.
.Releasing the Parking Brake.
.The transmission shifter is
moved out of P (Park) or
N (Neutral).
.Selecting the Cruise Control
On/Off button when it was
previously on.
.Pressing the Cruise Control Set
switch a second time.
.Pressing the accelerator greater
than a quarter of the down.
.Turning the ignition switch to the
LOCK/OFF position.

Black plate (42,1)GMC Sierra Owner Manual - 2011
9-42 Driving and Operating
Leaving the Vehicle With the
Engine Running
{WARNING
It can be dangerous to leave the
vehicle with the engine running.
The vehicle could move suddenly
if the shift lever is not fully in
P (Park) with the parking brake
firmly set.
If you have four-wheel drive and
the transfer case is in N (Neutral),
the vehicle will be free to roll,
even if the shift lever is in
P (Park). So be sure the transfer
case is in a drive gear—not in
N (Neutral).
(Continued)
WARNING (Continued)
And, if you leave the vehicle
with the engine running, it could
overheat and even catch fire.
You or others could be injured.
Do not leave the vehicle with
the engine running unless you
have to.
If you have to leave the vehicle
with the engine running, be sure
your vehicle is in P (Park) and the
parking brake is firmly set before
you leave it. After you move the shift
lever into P (Park), hold the regular
brake pedal down. Then, see if you
can move the shift lever away from
P (Park) without first pulling it toward
you. If you can, it means that the
shift lever was not fully locked into
P (Park).
Torque Lock
If you are parking on a hill and
you do not shift your transmission
into P (Park) properly, the weight
of the vehicle may put too much
force on the parking pawl in the
transmission. You may find it difficult
to pull the shift lever out of P (Park).
This is called torque lock. To
prevent torque lock, set the parking
brake and then shift into P (Park)
properly before you leave the driver
seat. To find out how, Shifting Into
Park on page 9‑41.
When you are ready to drive, move
the shift lever out of P (Park) before
you release the parking brake.
If torque lock does occur, you may
need to have another vehicle push
yours a little uphill to take some of
the pressure from the parking pawl
in the transmission, then you will be
able to pull the shift lever out of
P (Park).