
Black plate (28,1)Chevrolet Silverado Owner Manual - 2012
9-28 Driving and Operating
If the vehicle must be shut off in an
emergency:
1. Brake using a firm and steadypressure. 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, continue to firmly
apply the brakes and steer the
vehicle to a safe location.
3. Come to a complete stop. Shift to P (Park) with an
automatic transmission,
or Neutral with a manual
transmission. Turn the ignition
to LOCK/OFF.
4. Set the parking brake. See Parking Brake on page 9‑60.{WARNING
Turning off the vehicle while
moving may cause loss of power
assist in the brake and steering
systems and disable the airbags.
While driving, only shut the
vehicle off in an emergency.
If the vehicle cannot be pulled
over, and must be shut off while
driving, turn the ignition to
ACC/ACCESSORY.
On vehicles with an automatic
transmission, the shift lever
must be in P (Park) to turn the
ignition switch to LOCK/OFF.
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.
C (ON/RUN): This position can be
used to operate the electrical
accessories and to display some
instrument panel cluster warning
and indicator lights. This position
can also be used for service and
diagnostics, and to verify the proper
operation of the malfunction
indicator lamp as may be required
for emission inspection purposes.

Black plate (29,1)Chevrolet Silverado Owner Manual - 2012
Driving and Operating 9-29
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.
If the vehicle is equipped with a
radio, a warning tone will sound
when the driver door is opened, the
ignition is in ACC/ACCESSORY or
LOCK/OFF and the key is in the
ignition.Starting the Engine
If the vehicle has a diesel engine,
see the Duramax diesel supplement
for more information.
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
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.
Place the transmission in the
proper gear.
Automatic Transmission
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: 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.
Manual Transmission
The shift lever should be in
N (Neutral) and the parking brake
engaged. Hold the clutch pedal
down to the floor and start the
engine. The vehicle will not start
if the clutch pedal is not all the
way down.

Black plate (30,1)Chevrolet Silverado Owner Manual - 2012
9-30 Driving and Operating
Starting Procedure
1. With your foot off the acceleratorpedal, 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.
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 (32,1)Chevrolet Silverado Owner Manual - 2012
9-32 Driving and Operating
Retained Accessory
Power (RAP)
The following vehicle accessories
can be used for up to 10 minutes
after the engine is turned off:
.Audio System
.Power Windows
.OnStar System (if equipped)
.Sunroof (if equipped)
These features work when
the key is in ON/RUN or ACC/
ACCESSORY. Once the key is
turned from ON/RUN to LOCK/OFF,
the windows and sunroof continue
to work up to 10 minutes until any
door is opened. The radio continues
to work for up to 10 minutes or until
the driver door is opened.
Engine Coolant Heater
The engine heater can provide
easier starting and better fuel
economy during engine warm-up in
cold weather conditions at or below
−18°C (0°F). Vehicles with an
engine heater should be plugged in
at least four hours before starting.
An internal thermostat in the
plug-end of the cord may exist
which will prevent engine coolant
heater operation at temperatures
above −18°C (0°F).
If the vehicle has a diesel engine,
see the Duramax Diesel supplement
for more information.
To Use the Engine Coolant
Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord. The cord is
secured to the Engine
Compartment Fuse Block with a
clip. Carefully remove the wire
tie which bundles the electrical
plug. Do not cut the
electrical cord.
3. Plug the cord into a normal, grounded 110-volt AC outlet.
{WARNING
Plugging the cord into an
ungrounded outlet could cause an
electrical shock. Also, the wrong
kind of extension cord could
overheat and cause a fire.
(Continued)

Black plate (33,1)Chevrolet Silverado Owner Manual - 2012
Driving and Operating 9-33
WARNING (Continued)
You could be seriously injured.
Plug the cord into a properly
grounded three-prong 110-volt AC
outlet. If the cord will not reach,
use a heavy-duty three-prong
extension cord rated for at least
15 amps.
4. Before starting the engine, be sure to unplug and store the
cord as it was before to keep it
away from moving engine parts.
If you do not, it could be
damaged.
The length of time the heater should
remain plugged in depends on
several factors. Ask a dealer in the
area where you will be parking the
vehicle for the best advice on this.
Shifting Into Park
{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 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, use the steps
that follow. With four-wheel drive,
if 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). If you
are pulling a trailer, see Driving
Characteristics and Towing Tips
on page 9‑82. 1. Hold the brake pedal down,
then set the parking brake.
See Parking Brake on page 9‑60
for more information.
2. Move the shift lever into the P (Park) position by pulling the
shift lever toward you and
moving it up as far as it will go.
3. Be sure the transfer case is in a drive gear —not in N (Neutral).
4. Turn the ignition key to LOCK/OFF.
5. Remove the key and take it with you. If you can leave the vehicle
with the ignition key in your
hand, the vehicle is in P (Park).

Black plate (35,1)Chevrolet Silverado Owner Manual - 2012
Driving and Operating 9-35
Shifting out of Park
This vehicle is equipped with
an electronic shift lock release
system. The shift lock release is
designed to:
.Prevent ignition key removal
unless the shift lever is in
P (Park) with the shift lever
button fully released.
.Prevent movement of the shift
lever out of P (Park), unless
the ignition is in ON/RUN or
ACC/ACCESSORY and the
regular brake pedal is applied.
The shift lock release is always
functional except in the case of an
uncharged or low voltage (less than
9 volt) battery.
If the vehicle has an uncharged
battery or a battery with low voltage,
try charging or jump starting the
battery. See Jump Starting on
page 10‑92 for more information. To shift out of P (Park) use the
following:
1. Apply the brake pedal.
2. Move the shift lever to the
desired position.
If you still are unable to shift out of
P (Park):
1. Ease the pressure on the shift lever.
2. While holding down the brake pedal, press the shift lever all
the way into P (Park).
3. Move the shift lever to the desired position.
If you are still having a problem
shifting, then have the vehicle
serviced soon.
Parking (Manual
Transmission)
If the vehicle has a manual
transmission, before you get out of
the vehicle, move the shift lever into
R (Reverse), and firmly apply the
parking brake. Once the shift lever
has been placed into R (Reverse)
with the clutch pedal pressed in,
turn the ignition key to LOCK/OFF,
remove the key and release the
clutch.
If you are parking on a hill, or if the
vehicle is pulling a trailer, see
Driving Characteristics and Towing
Tips on page 9‑82.
Parking over Things
That Burn
{WARNING
Things that can burn could touch
hot exhaust parts under the
vehicle and ignite. Do not park
over papers, leaves, dry grass,
or other things that can burn.

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 (40,1)Chevrolet Silverado Owner Manual - 2012
9-40 Driving and Operating
D (Drive) can be used when towing
a trailer, carrying a heavy load,
driving on steep hills, or for off-road
driving. You might want to shift the
transmission to a lower gear
selection if the transmission shifts
too often.
Downshifting the transmission in
slippery road conditions could result
in skidding. See“Skidding”under
Loss of Control on page 9‑5.
The vehicle has a shift stabilization
feature that adjusts the transmission
shifting to the current driving
conditions in order to reduce rapid
upshifts and downshifts. This shift
stabilization feature is designed to
determine, before making an
upshift, if the engine is able to
maintain vehicle speed by analyzing
things such as vehicle speed,
throttle position, and vehicle load. If the shift stabilization feature
determines that a current vehicle
speed cannot be maintained, the
transmission does not upshift and
instead holds the current gear.
In some cases, this could appear to
be a delayed shift, however the
transmission is operating normally.
The transmission uses adaptive
shift controls. Adaptive shift
controls continually compares
key shift parameters to
pre-programmed ideal shifts
stored in the transmissions
computer. The transmission
constantly makes adjustments to
improve vehicle performance
according to how the vehicle is
being used, such as with a heavy
load or when temperature changes.
During this adaptive shift control
process, shifting might feel different
as the transmission determines the
best settings.When temperatures are very cold,
the Allison Transmission and
Hydra-Matic 6-Speed transmission's
gear shifting could be delayed
providing more stable shifts until the
engine warms up. Shifts could be
more noticeable with a cold
transmission. This difference in
shifting is normal.
M (Manual Mode):
This position
is available on vehicles with the
Allison Transmission or Hydra-Matic
6-Speed transmission. It lets
drivers select the range of gears
appropriate for current driving
conditions. If the vehicle has this
feature, see “Range Selection
Mode” underManual Mode on
page 9‑42.
3 (Third): This position is also used
for normal driving. It reduces vehicle
speed more than D (Drive) without
using the brakes. You might choose
3 (Third) instead of D (Drive) when