2012 CHEVROLET SILVERADO automatic transmission

Black plate (38,1)Chevrolet Silverado Owner Manual - 2012
9-38 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 9‑42.
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 9‑33 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
could be injured. To be sure the
vehicle will not move, even when
you are on fairly level ground,
always set the parking brake and
move the shift lever to P (Park).
See Shifting Into Park on
page 9‑33. If you are pulling a
trailer, see Driving Characteristics
and Towing Tips on page 9‑82.

Black plate (41,1)Chevrolet Silverado Owner Manual - 2012
Driving and Operating 9-41
driving on hilly, winding roads,
when towing a trailer, so there is
less shifting between gears and
when going down a steep hill.
2 (Second):This position reduces
vehicle speed even more than
3 (Third) without using the brakes.
You can use 2 (Second) on hills.
It can help control vehicle speed as
you go down steep mountain roads,
but then you would also want to use
the brakes off and on.
If you manually select 2 (Second) in
an automatic transmission, the
transmission will start in second
gear. You can use this feature for
reducing the speed of the rear
wheels when you are trying to start
the vehicle from a stop on slippery
road surfaces. 1 (First):
For the Hydra-Matic
4-Speed transmission this position
reduces vehicle speed even more
than 2 (Second) without using the
brakes. You can use it on very steep
hills, or in deep snow or mud. If the
shift lever is put in 1 (First) while the
vehicle is moving forward, the
transmission does not shift into first
gear until the vehicle is going slowly
enough.
For an Allison Transmission or
Hydra-Matic 6-Speed transmission,
this position reduces vehicle
speed without using the brakes.
You can use it for major/severe
downgrades and off-road driving
where the vehicle would otherwise
accelerate due to steepness
of grade. When you shift to
1 (First) it provides the lowest gear
appropriate to current road speed and continues to downshift as
the vehicle slows, eventually
downshifting to 1 (First) gear.
Notice:
Spinning the tires or
holding the vehicle in one
place on a hill using only the
accelerator pedal may damage
the transmission. The repair will
not be covered by the vehicle
warranty. If you are stuck, do not
spin the tires. When stopping on
a hill, use the brakes to hold the
vehicle in place.

Black plate (42,1)Chevrolet Silverado Owner Manual - 2012
9-42 Driving and Operating
Manual Mode
Range Selection Mode
(Allison®Transmission or
Hydra-Matic®6-Speed
Transmission)
The vehicle may have a Range
Selection Mode. The Range
Selection Mode helps control the
vehicle's transmission and vehicle
speed while driving down hill or
towing a trailer by letting you select
a desired range of gears.
To use this feature, do the following:
1. Move the shift lever to
M (Manual Mode).
2. Press the plus/minus buttons, located on the steering column
shift lever, to select the desired
range of gears for current driving
conditions. When M (Manual Mode) is selected
a number displays next to the M,
indicating the current gear.
This number is the highest gear that
can be used. However, the vehicle
can automatically shift to lower
gears as it adjusts to driving
conditions. This means that all
gears below that number are
available. When 5 (Fifth) is selected,
1 (First) through 5 (Fifth) gears are
automatically shifted by the vehicle,
but 6 (Sixth) cannot be used until
the plus/minus button located on the
steering column lever is used to
change to the gear.
Grade Braking is not available when
Range Selection Mode is active.
See
Tow/Haul Mode on page 9‑43.
While using Range Selection Mode,
Cruise Control and the Tow/Haul
Mode can be used.
If the vehicle has an exhaust brake,
it can also be used, but will not
automatically downshift the
transmission. See Exhaust Brake in
the Duramax Diesel supplement. Notice:
Spinning the tires or
holding the vehicle in one
place on a hill using only the
accelerator pedal may damage
the transmission. The repair will
not be covered by the vehicle
warranty. If you are stuck, do not
spin the tires. When stopping on
a hill, use the brakes to hold the
vehicle in place.
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.

Black plate (43,1)Chevrolet Silverado Owner Manual - 2012
Driving and Operating 9-43
Tow/Haul Mode
4-Speed Automatic Transmission
6-Speed Automatic Transmission
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 driving down steep hills or
Mountain grades, 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 Mode is enabled, a light
on the instrument panel cluster
will come on.
See
Tow/Haul Mode Light on
page 5‑28 andHill and Mountain
Roads on page 9‑13 for more
information.
Also see “Tow/Haul Mode” under
Towing Equipment on page 9‑102
for more information.Grade Braking (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 9‑42 for more information on
the Range Selection Mode. Grade
Braking assists in maintaining
desired vehicle speeds when driving
on downhill grades by automatically
implementing a shift schedule that
utilizes the engine and transmission
to slow the vehicle. This reduces
wear on the braking system and
increases control of the vehicle.
Grade Braking monitors vehicle
speed, acceleration, engine torque
and brake pedal usage. Using this
information, it detects when the
truck is on a downhill grade and the
driver desires to slow the vehicle by
pressing the brake.
This feature is active when
the exhaust brake is enabled
(if equipped).
Also see Towing Equipment on
page 9‑102 for more information.

Black plate (45,1)Chevrolet Silverado Owner Manual - 2012
Driving and Operating 9-45
Notice:Shifting to R (Reverse)
while the vehicle is moving
forward could damage the
transmission. The repairs would
not be covered by the vehicle
warranty. Shift to R (Reverse) only
after the vehicle is stopped.
Use R (Reverse), along with the
parking brake, for parking the
vehicle.
Shift Speeds
{WARNING
If you skip a gear when you
downshift, you could lose control
of the vehicle. You could injure
yourself or others. Do not shift
down more than one gear at a
time when you downshift.
Drive Systems
Four-Wheel Drive
If the vehicle has Four-Wheel Drive,
you can send the engine's driving
power to all four wheels for extra
traction. To get the most satisfaction
out of Four-Wheel Drive, you must
be familiar with its operation.
Read the following before using
Four-Wheel Drive. See the
appropriate text for the transfer
case in the vehicle.
Notice: Driving on clean, dry
pavement in Four-Wheel Drive
High or Four-Wheel Drive Low
for an extended period of time
may cause premature wear on
the vehicle's powertrain.
Do not drive on clean, dry
pavement in Four-Wheel Drive
High or Four-Wheel Drive Low
for extended periods of time. While driving on clean dry pavement
and during tight turns, you may
experience vibration in the steering
system.
If the vehicle has StabiliTrak®,
shifting into Four-Wheel Drive Low
will turn Traction Control and
StabiliTrak off. See StabiliTrak
®
System on page 9‑62.
Front Axle
The front axle engages and
disengages automatically when
you shift the transfer case.
Some delay for the axle to engage
or disengage is normal.

Black plate (54,1)Chevrolet Silverado Owner Manual - 2012
9-54 Driving and Operating
4. Release the parking brake priorto moving the vehicle.
Notice: Shifting the transmission
into gear before the requested
mode indicator light has stopped
flashing could damage the
transfer case. To help avoid
damaging the vehicle, always wait
for the mode indicator lights to
stop flashing before shifting the
transmission into gear.
5. Start the engine and shift the transmission to the desired
position.
Excessively shifting the transfer
case into or out of the different
modes may cause the transfer case
to enter the shift protection mode.
This will protect the transfer case
from possible damage and will only
allow the transfer case to respond
to one shift per 10 seconds.
The transfer case may stay in this
mode for up to three minutes.Automatic Transfer Case
The transfer case knob is located
next to the steering column.
Use the dial to shift into and out of
Four-Wheel Drive.
You can choose among five driving
settings:
Indicator lights in the dial show
which setting you are in. The
indicator lights will come on briefly
when you turn on the ignition and
one will stay on. If the lights do not
come on, you should take the
vehicle to your dealer for service. An indicator light will flash while
shifting the transfer case. It will
remain illuminated when the shift is
complete. If for some reason the
transfer case cannot make a
requested shift, it will return to the
last chosen setting.
2
m(Two-Wheel Drive High):
This setting is used for driving in
most street and highway situations.
The front axle is not engaged in
Two-Wheel Drive. This setting also
provides the best fuel economy.
AUTO (Automatic Four-Wheel
Drive): This setting is ideal for
use when road surface traction
conditions are variable. When
driving the vehicle in AUTO, the
front axle is engaged, but the
vehicle's power is sent only to
the front and rear wheels
automatically based on driving
conditions. Driving in this mode
results in slightly lower fuel
economy than Two-Wheel
Drive High.

Black plate (55,1)Chevrolet Silverado Owner Manual - 2012
Driving and Operating 9-55
4m(Four-Wheel Drive High):
Use the Four-Wheel Drive High
position when extra traction is
needed, such as on snowy or icy
roads or in most off-road situations.
This setting also engages the front
axle to help drive the vehicle.
This is the best setting to use when
plowing snow.
4
n(Four-Wheel Drive Low): This
setting also engages the front axle
and delivers extra torque. You may
never need this setting. 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.
If the vehicle has StabiliTrak
®,
shifting into Four-Wheel Drive Low
will turn Traction Control and
StabiliTrak off. See StabiliTrak
®
System on page 9‑62.
{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). SeeParking Brake on
page 9‑60.
N (Neutral): Shift the vehicle's
transfer case to N (Neutral) only
when towing the vehicle. See
Recreational Vehicle Towing on
page 10‑97 orTowing the Vehicle
on page 10‑97 for more information.
If the SERVICE 4 WHEEL DRIVE
message stays on, you should
take the vehicle to your dealer
for service. See “SERVICE
4 WHEEL DRIVE message”
under Transmission Messages on
page 5‑50. Shifting Into Four-Wheel Drive
High or AUTO (Automatic
Four-Wheel Drive)
Turn the knob to the Four-Wheel
Drive High or AUTO position. This
can be done at any speed, except
when shifting from Four-Wheel
Drive Low. The indicator light will
flash while shifting. It will remain on
when the shift is completed.
Shifting Into Two-Wheel
Drive High
Turn the knob to the Two-Wheel
Drive High position. This can be
done at any speed, except when
shifting from Four-Wheel Drive Low.
The indicator light will flash while
shifting. It will remain on when the
shift is completed.

Black plate (65,1)Chevrolet Silverado Owner Manual - 2012
Driving and Operating 9-65
If traction control is turned off,
only the brake-traction control
portion of traction control will work.
The engine speed management will
be disabled. In this mode, engine
power is not reduced automatically
and the driven wheels can spin
more freely. This can cause the
brake-traction control to activate
constantly.
Notice:If the wheel(s) of one axle
is allowed to spin excessively
while the StabiliTrak
®, ABS, brake
warning lights, and any relevant
DIC messages are displayed, the
transfer case could be damaged.
The repairs would not be covered
by the vehicle warranty. Reduce
engine power and do not spin the
wheel(s) excessively while these
lights and messages are
displayed.
The TCS may activate on dry or
rough roads or under conditions
such as heavy acceleration while turning or abrupt upshifts/downshifts
of the transmission. When this
happens, a reduction in acceleration
may be noticed, or a noise or
vibration may be heard. This is
normal.
If cruise control is being used when
the system activates, the StabiliTrak
light will flash and cruise control
will automatically disengage.
Cruise control may be reengaged
when road conditions allow.
See
Cruise Control on page 9‑66.
StabiliTrak may also turn off
automatically if it determines that a
problem exists with the system.
If the problem does not clear itself
after restarting the vehicle, see your
dealer for service.
Non-hybrid vehicles with StabiliTrak
have a Trailer Sway Control (TSC)
feature. See Trailer Sway Control
(TSC) on page 9‑114. Non-hybrid vehicles with StabiliTrak
have a Hill Start Assist (HSA)
feature. See
Hill Start Assist (HSA)
on page 9‑62.
Adding non‐dealer accessories can
affect the vehicle's performance.
See Accessories and Modifications
on page 10‑3.
Locking Rear Axle
Vehicles with a locking rear axle can
give more traction on snow, mud,
ice, sand, or gravel. It works like a
standard axle most of the time, but
when traction is low, this feature will
allow the rear wheel with the most
traction to move the vehicle.