2012 GMC SIERRA 1500 tow

Black plate (2,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
6-2 Lighting
The exterior lamps control has
four positions:
O(Off):Turns off the automatic
headlamps and Daytime Running
Lamps (DRL). Turn the headlamp
control to the off position again to
turn the automatic headlamps or
DRL back on.
For vehicles first sold in Canada,
the off position will only work when
the vehicle is shifted into P (Park).
AUTO (Automatic): Automatically
turns on the headlamps at normal
brightness, together with the
following:
.Parking Lamps
.Instrument Panel Lights
.Taillamps
.License Plate Lamps
.Roof Marker Lamps
(If Equipped)
When the vehicle is turned off and
the headlamps are in AUTO, the
headlamps may automatically
remain on for a set time. The time of the delay can be changed using the
DIC. See
Driver Information Center
(DIC) on page 5‑30
;(Parking Lamps): Turns on the
parking lamps together with the
following:
.Instrument Panel Lights
.Taillamps
.License Plate Lamps
.Roof Marker Lamps
(If Equipped)
2(Headlamps): Turns on the
headlamps together with the
following:
.Parking Lamps
.Instrument Panel Lights
.Taillamps
.License Plate Lamps
.Roof Marker Lamps (If
Equipped)
When the headlamps are turned
on while the vehicle is on, the
headlamps turn off automatically 10 minutes after the ignition is
turned off. When the headlamps are
turned on while the vehicle is off,
the headlamps will stay on for
10 minutes before automatically
turning off to prevent the battery
from being drained. Turn the
headlamp control to off and then
back to the headlamp on position to
make the headlamps stay on for an
additional 10 minutes.
Push the turn signal/multifunction
lever toward the instrument panel to
change the headlamps from low
beam to high beam.
Exterior Lamps Off
Reminder
For vehicles with a radio, a reminder
chime sounds when the headlamps
or parking lamps are manually
turned on, the ignition is off, and a
door is open. To disable the chime,
turn the lamp off.

Black plate (3,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Lighting 6-3
Headlamp High/
Low-Beam Changer
5 3
(Headlamp High/Low
Beam Changer): To change the
headlamps from low to high beam,
push the lever toward the instrument
panel. To return to low-beam
headlamps, pull the multifunction
lever toward you. Then release it.
When the high beams are on, this
indicator light on the instrument
panel cluster will also be on.
Flash-to-Pass
This feature lets you use the
high-beam headlamps to signal
a driver in front of you that you want
to pass. It works even if the
headlamps are in the automatic
position. To use it, pull the turn signal lever
toward you, then release it.
If the headlamps are in the
automatic position or on low
beam, the high-beam headlamps
will turn on. They will stay on as
long as you hold the lever toward
you. The high-beam indicator on the
instrument panel cluster will come
on. Release the lever to return to
normal operation.
Daytime Running
Lamps (DRL)
Daytime Running Lamps (DRL) can
make it easier for others to see the
front of your vehicle during the day.
Fully functional daytime running
lamps are required on all vehicles
first sold in Canada.
The DRL system comes on when
the following conditions are met:
.The ignition is on.
.The exterior lamps control is
in AUTO.
.The transmission is not in Park.
.The light sensor determines it is
daytime.
When the DRL system is on,
only the DRL lamps are on. The
taillamps, sidemarker, instrument
panel lights, and other lamps will not
be on.
When it begins to get dark, the
automatic headlamp system
switches from DRL to the
headlamps.
To turn off the DRL lamps, turn the
exterior lamps control to the OFF
position and then release. For
vehicles first sold in Canada, the
transmission must be in the P (Park)
position before the DRL lamps can
be turned off.

Black plate (5,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Lighting 6-5
If the vehicle is not equipped
with DIC buttons, exit lighting is
automatic. When it is dark enough
outside, the exterior lamps remain
on for 30 seconds after the ignition
is moved from ON/RUN to
LOCK/OFF.
For vehicles without a radio, the
instrument panel light remains on for
30 seconds with the driver door
closed. For vehicles with a radio,
the instrument panel light remains
on for 10 minutes with the driver
door closed. SeeRetained
Accessory Power (RAP) on
page 9‑29.
The regular headlamp system can
be turned on when needed.Hazard Warning Flashers
|(Hazard Warning Flashers):
Press this button located on top of
the steering column, to make the
front and rear turn signal lamps
flash on and off. This warns others
that you are having trouble. Press
again to turn the flashers off.
When the hazard warning flashers
are on, the vehicle's turn signals will
not work.
Turn and Lane-Change
Signals
An arrow on the instrument panel
cluster flashes in the direction of the
turn or lane change.
Move the lever all the way up or
down to signal a turn.
Raise or lower the lever for less
than one second until the arrow
starts to flash to signal a lane
change. This causes the turn
signals to automatically flash
three times. It will flash six times
if tow-haul mode is active.

Black plate (45,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Infotainment System 7-45
Tips and Troubleshooting Chart (cont'd)
ProblemRecommended Action
Sometimes the wireless headphone audio cuts out or
buzzes. Check for obstructions, low batteries, reception range,
and interference from cellular telephone towers, or use a
cellular telephone in the vehicle.
Check that the headphones are on correctly using
the L (left) and R (right) on the headphones.
The remote and/or the headphones are lost. See your dealer for assistance.
The DVD is playing, but there is no picture or sound. Check that the RSE video screen is sourced to the DVD player.
DVD Display Error Messages
The DVD display error message
depends on the radio that is in the
vehicle. The video screen can
display one of the following:
Disc Load/Eject Error:This
message displays when there are
disc load or eject problems.
Disc Format Error: This message
displays if the disc is inserted with
the disc label wrong side up, or if
the disc is damaged. Disc Region Error:
This message
displays if the disc is not from a
correct region.
No Disc Inserted: This message
displays if no disc is present when
EJECT or DVD AUX is pressed on
the radio.
DVD Distortion
Video distortion can occur when
operating cellular phones, scanners,
CB radios, Global Position Systems
(GPS)*, two-way radios, mobile fax
machines, or walkie talkies. It might be necessary to turn off the
DVD player when operating one of
these devices in or near the vehicle.
*Excludes the OnStar® System.
Cleaning the RSE Overhead
Console
When cleaning the RSE overhead
console surface, use only a clean
cloth dampened with clean water.

Black plate (7,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Climate Controls 8-7
help quickly cool down the air
inside the vehicle. The light
on the button comes on in
recirculation.
2. Set the driver and passenger temperature.
To find your comfort setting, start
with a 23°C (74°F) temperature
setting and allow about
20 minutes for the system to
regulate. Use the driver or
passenger temperature buttons
to adjust the temperature setting
as necessary. If a temperature
setting of 15°C (60°F) is chosen,
the system remains at the
maximum cooling setting. If a
temperature setting of 32°C
(90°F) is chosen, the system
remains at the maximum heat
setting. Choosing either
maximum setting will not cause
the vehicle to heat or cool any
faster.
Do not cover the solar sensor
located on the top of the instrument
panel near the windshield. This sensor regulates air temperature
based on sun load. For more
information on the solar sensor, see
“Sensors”
later in this section.
To avoid blowing cold air in cold
weather, the system delays turning
the fan on until warm air is
available. The length of delay
depends on the engine coolant
temperature. Pressing the fan
switch overrides this delay and
changes the fan to a selected
speed.
Manual Operation
D C(Fan Control): Press these
buttons to increase or decrease the
fan speed.
Pressing either fan button while in
automatic control places the fan
under manual control. The fan
setting remains displayed and the
AUTO light turns off. The air
delivery mode remains under
automatic control.
H G(Air Delivery Mode Control):
Press these buttons to change the
direction of the airflow in the vehicle.
Repeatedly press either button until
the desired mode appears on the
display.
Pressing either mode button while
the system is off changes the air
delivery mode without turning the
system on.
Pressing either mode button while
in automatic control places the
mode under manual control. The air
delivery mode setting displays and
the AUTO light turns off. The fan
remains under automatic control.
H(Vent): Air is directed to the
instrument panel outlets.
)(Bi-Level): Air is divided
between the instrument panel and
floor outlets. Some air is directed
toward the windshield and side
window outlets.

Black plate (1,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-1
Driving and
Operating
Driving Information
Distracted Driving . . . . . . . . . . . . . 9-2
Defensive Driving . . . . . . . . . . . . . 9-3
Drunk Driving . . . . . . . . . . . . . . . . . 9-3
Control of a Vehicle . . . . . . . . . . . 9-4
Braking . . . . . . . . . . . . . . . . . . . . . . . 9-4
Steering . . . . . . . . . . . . . . . . . . . . . . . 9-4
Off-Road Recovery . . . . . . . . . . . . 9-5
Loss of Control . . . . . . . . . . . . . . . . 9-5
Off-Road Driving . . . . . . . . . . . . . . 9-6
Driving on Wet Roads . . . . . . . . 9-11
Highway Hypnosis . . . . . . . . . . . 9-12
Hill and Mountain Roads . . . . . 9-12
Winter Driving . . . . . . . . . . . . . . . 9-13
If the Vehicle Is Stuck . . . . . . . . 9-15
Vehicle Load Limits . . . . . . . . . . 9-16
Truck-Camper LoadingInformation . . . . . . . . . . . . . . . . . 9-23
Starting and Operating
New Vehicle Break-In . . . . . . . . 9-25
Adjustable Throttle and BrakePedal . . . . . . . . . . . . . . . . . . . . . . . 9-25
Ignition Positions . . . . . . . . . . . . 9-26 Starting the Engine . . . . . . . . . . 9-27
Fast Idle System . . . . . . . . . . . . . 9-29
Retained Accessory
Power (RAP) . . . . . . . . . . . . . . . 9-29
Engine Coolant Heater . . . . . . . 9-30
Shifting Into Park . . . . . . . . . . . . 9-30
Shifting out of Park . . . . . . . . . . 9-32
Parking over Things
That Burn . . . . . . . . . . . . . . . . . . 9-32
Active Fuel Management
®. . . 9-32
Engine Exhaust
Engine Exhaust . . . . . . . . . . . . . . 9-33
Running the Vehicle While Parked . . . . . . . . . . . . . . . . . . . . . 9-34
Automatic Transmission
Automatic Transmission . . . . . 9-35
Manual Mode . . . . . . . . . . . . . . . . 9-38
Tow/Haul Mode . . . . . . . . . . . . . . 9-39
Drive Systems
Four-Wheel Drive . . . . . . . . . . . . 9-40
Brakes
Antilock BrakeSystem (ABS) . . . . . . . . . . . . . . 9-53
Parking Brake . . . . . . . . . . . . . . . 9-54
Brake Assist . . . . . . . . . . . . . . . . . 9-54
Hill Start Assist (HSA) . . . . . . . 9-54
Ride Control Systems
StabiliTrak®System . . . . . . . . . 9-55
Locking Rear Axle . . . . . . . . . . . 9-58
Cruise Control
Cruise Control . . . . . . . . . . . . . . . 9-58
Object Detection Systems
Ultrasonic Parking Assist . . . . 9-61
Rear Vision Camera (RVC) . . . . . . . . . . . . . 9-62
Fuel
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . 9-68
Recommended Fuel . . . . . . . . . 9-68
Gasoline Specifications (U.S.and Canada Only) . . . . . . . . . . 9-69
California Fuel Requirements . . . . . . . . . . . . . . 9-69
Fuels in Foreign Countries . . . 9-69
Fuel Additives . . . . . . . . . . . . . . . 9-70
Fuel E85 (85% Ethanol) . . . . . 9-71
Filling the Tank . . . . . . . . . . . . . . 9-72
Filling a Portable Fuel Container . . . . . . . . . . . . . . . . . . . 9-73

Black plate (2,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-2 Driving and Operating
Towing
General TowingInformation . . . . . . . . . . . . . . . . . 9-74
Driving Characteristics and Towing Tips . . . . . . . . . . . . . . . . 9-74
Trailer Towing . . . . . . . . . . . . . . . . 9-78
Towing Equipment . . . . . . . . . . . 9-94
Trailer Sway
Control (TSC) . . . . . . . . . . . . . 9-105
Conversions and Add-Ons
Add-On ElectricalEquipment . . . . . . . . . . . . . . . . 9-105
Adding a Snow Plow or Similar Equipment . . . . . . . . 9-106
Pickup Conversion to Chassis Cab . . . . . . . . . . . . . . 9-109
Driving Information
Distracted Driving
Distraction comes in many forms
and can take your focus from the
task of driving. Exercise good
judgment and do not let other
activities divert your attention
away from the road. Many local
governments have enacted laws
regarding driver distraction.
Become familiar with the local
laws in your area.
To avoid distracted driving, always
keep your eyes on the road, hands
on the wheel, and mind on the drive.
.Do not use a phone in
demanding driving situations.
Use a hands-free method to
place or receive necessary
phone calls.
.Watch the road. Do not
read, take notes, or look up
information on phones or other
electronic devices.
.Designate a front seat
passenger to handle potential
distractions.
.Become familiar with vehicle
features before driving, such as
programming favorite radio
stations and adjusting climate
control and seat settings.
Program all trip information into
any navigation device prior to
driving.
.Wait until the vehicle is parked
to retrieve items that have fallen
to the floor.
.Stop or park the vehicle to tend
to children.
.Keep pets in an appropriate
carrier or restraint.
.Avoid stressful conversations
while driving, whether with a
passenger or on a cell phone.

Black plate (15,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-15
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 56 km/h (35 mph).
For information about using tire
chains on the vehicle, see Tire
Chains on page 10‑74.
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 10‑93.