trailer GMC SIERRA 1500 2012 User Guide

Black plate (38,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
5-38 Instruments and Controls
Trailer Gain and Output
On vehicles with the Integrated
Trailer Brake Control (ITBC) system,
the trailer brake display appears in
the DIC. Press the trip odometer
reset stem until TRAILER GAIN and
OUTPUT display.
TRAILER GAIN shows the trailer
gain setting. This setting can be
adjusted from 0.0 to 10.0 with either
a trailer connected or disconnected.
OUTPUT shows the power output to
the trailer any time a trailer with
electric brakes is connected. Output
is displayed in 0 to 10 bars. Dashes
may appear in the OUTPUT display.
To adjust trailer gain see“Integrated
Trailer Brake Control System” under
Towing Equipment on page 9‑94 for
more information.
Speedometer
The speedometer shows how fast
the vehicle is moving in either
kilometers per hour (km/h) or miles
per hour (mph). The speedometer
cannot be reset. Battery
This display shows the current
battery voltage. If the voltage is in
the normal range, the value will
display. For example, the display
may read BATTERY 13 VOLTS.
Your vehicle's charging system
regulates voltage based on the state
of the battery. The battery voltage
may fluctuate when viewing this
information on the DIC. This is
normal.
Oil Pressure
This display shows the oil pressure
in either kilopascals (kPa) or pounds
per square inch (psi).
Compass Zone Setting
This display allows for setting the
compass zone. See
Compass on
page 5‑5 for more information.
Compass Recalibration
This display allows for calibrating
the compass. See Compass on
page 5‑5 for more information. Oil Life
To access this display, the vehicle
must be in P (Park). Press the trip
odometer reset stem until OIL LIFE
REMAINING displays. This display
shows an estimate of the oil's
remaining useful life. If you see
99% OIL LIFE REMAINING on the
display, that means 99% of the
current oil life remains. The engine
oil life system will alert you to
change the oil on a schedule
consistent with your driving
conditions.
When the remaining oil life is low,
the CHANGE ENGINE OIL SOON
message will appear on the display.
See
“CHANGE ENGINE OIL SOON”
under Engine Oil Messages on
page 5‑42. You should change the
oil as soon as you can. See Engine
Oil on page 10‑7. In addition to the
engine oil life system monitoring the
oil life, additional maintenance is
recommended in the Maintenance
Schedule in this manual. See
Maintenance Schedule on
page 11‑3 for more information.

Black plate (40,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
5-40 Instruments and Controls
SERVICE BATTERY
CHARGING SYSTEM
On some vehicles, this message
displays if there is a problem with
the battery charging system. Under
certain conditions, the charging
system light may also turn on in
the instrument panel cluster. See
Charging System Light on
page 5‑22. Driving with this problem
could drain the battery. Turn off all
unnecessary accessories. Have the
electrical system checked as soon
as possible. See your dealer.
Brake System Messages
SERVICE BRAKE SYSTEM
This message displays along with
the brake system warning light if
there is a problem with the brake
system. SeeBrake System Warning
Light on page 5‑25. If this message
appears, stop as soon as possible
and turn off the vehicle. Restart the
vehicle and check for the message
on the DIC display. If the message
is still displayed or appears again when you begin driving, the brake
system needs service as soon as
possible. See your dealer.
SERVICE BRAKES SOON
On some vehicles, this message
displays if there is a problem with
the brake system. If this message
appears, stop as soon as possible
and turn off the vehicle. Restart the
vehicle and check for the message
on the DIC display. If the message
is still displayed or appears again
when you begin driving, the brake
system needs service. See your
dealer.
SERVICE TRAILER BRAKE
SYSTEM
On vehicles with the Integrated
Trailer Brake Control (ITBC) system,
this message displays and a chime
may sound when there is a problem
with the ITBC system.
When this message displays, power
is no longer available to the trailer
brakes.
As soon as it is safe to do so,
carefully pull your vehicle over to
the side of the road and turn the
ignition off. Check the wiring
connection to the trailer and turn the
ignition back on. If this message still
displays, either your vehicle or the
trailer needs service. See your
dealer.
See
“Integrated Trailer Brake
Control System” underTowing
Equipment on page 9‑94 for more
information.
Door Ajar Messages
DRIVER DOOR OPEN
This message displays and a chime
may sound if the driver door is not
fully closed and the vehicle is
shifted out of P (Park). Stop and turn
off the vehicle, check the door for
obstructions, and close the door
again. Check to see if the message
still appears on the DIC.

Black plate (47,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Instruments and Controls 5-47
TRANSMISSION HOT IDLE
ENGINE
Notice:Do not drive the vehicle
while the transmission fluid is
overheating and the transmission
temperature warning is displayed
on the instrument panel cluster
and/or DIC, or the transmission
can be damaged. This could lead
to costly repairs that would not
be covered by the warranty.
This message displays and a chime
may sound if the transmission fluid
in the vehicle gets hot. Driving with
the transmission fluid temperature
high can cause damage to the
vehicle. Stop the vehicle and let it
idle to allow the transmission to
cool. This message clears and
the chime stops when the fluid
temperature reaches a safe level.
Vehicle Reminder
Messages
CHECK TRAILER WIRING
On vehicles with the Integrated
Trailer Brake Control (ITBC) system,
this message may display and a
chime may sound when one of the
following conditions exists:
.A trailer with electric brakes
becomes disconnected from the
vehicle.
‐ If the disconnect occurs while
the vehicle is stopped, this
message clears itself after a
short time.
‐ If the disconnect occurs while
the vehicle is moving, this
message stays on until the
ignition is turned off.
.There is a short in the wiring to
the electric trailer brakes.
When this message displays, power
is no longer available to the trailer
brakes. As soon as it is safe to do so,
carefully pull the vehicle over to the
side of the road and turn the ignition
off. Check the wiring connection to
the trailer and turn the ignition back
on. This message clears if the trailer
is reconnected. This message also
clears if you acknowledge it. If this
message still displays, either the
vehicle or the trailer needs service.
See your dealer.
See
“Integrated Trailer Brake
Control System” underTowing
Equipment on page 9‑94 for more
information.
ICE POSSIBLE DRIVE
WITH CARE
This message displays when ice
conditions are possible.
TRAILER CONNECTED
On vehicles with the Integrated
Trailer Brake Control (ITBC) system,
this message displays briefly when
a trailer with electric brakes is first
connected to the vehicle.

Black plate (48,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
5-48 Instruments and Controls
This message clears itself after
several seconds. This message also
clears if you acknowledge it. After
this message clears, the TRAILER
GAIN/OUTPUT display appears in
the DIC.
See“TRAILER GAIN/OUTPUT”
under Driver Information Center
(DIC) on page 5‑30 and“Integrated
Trailer Brake Control System” under
Towing Equipment on page 9‑94 for
more information.
Washer Fluid Messages
WASHER FLUID LOW ADD
FLUID
This message displays when the
windshield washer fluid is low. Fill
the windshield washer fluid reservoir
as soon as possible. See Engine
Compartment Overview on
page 10‑6 for the location of the
windshield washer fluid reservoir.
Also, see Washer Fluid on
page 10‑26 for more information.
Vehicle
Personalization
Vehicle Personalization
(With DIC Buttons)
The vehicle may have customization
capabilities that allow you to
program certain features to one
preferred setting. Customization
features can only be programmed
to one setting on the vehicle and
cannot be programmed to a
preferred setting for two different
drivers.
All of the customization options may
not be available on the vehicle.
Only the options available will be
displayed on the DIC.
The default settings for the
customization features were set
when the vehicle left the factory, but
may have been changed from their
default state since then.
The customization preferences are
automatically recalled. To change customization
preferences, use the following
procedure.
Entering the Feature
Settings Menu
1. Turn the ignition on and place
the vehicle in P (Park).
To avoid excessive drain on the
battery, turn the headlamps off.
2. Press the customization button to scroll through the available
customizable options.
Feature Settings Menu Items
The following customization features
allow you to program settings to the
vehicle:
DISPLAY IN ENGLISH
This feature will only display if a
language other than English has
been set. This feature allows you to
change the language in which the
DIC messages appear to English.

Black plate (9,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Lighting 6-9
Lighting Features
Entry Lighting
The vehicle has an illuminated entry
feature.
When the doors are opened, the
dome lamps will come on if the
dome override button is in the
extended position. If the dome
override button is pressed in, the
lamps will not come on.
Exit Lighting
The interior lamps come on when
the key is removed from the ignition.
They turn off automatically in
20 seconds. The lights do not come
on if the dome override button is
pressed in.
Battery Load
Management
The vehicle has Electric Power
Management (EPM) that estimates
the battery's temperature and state
of charge. It then adjusts the voltage
for best performance and extended
life of the battery.
When the battery's state of charge
is low, the voltage is raised slightly
to quickly bring the charge back up.
When the state of charge is high,
the voltage is lowered slightly to
prevent overcharging. If the vehicle
has a voltmeter gauge or a voltage
display on the Driver Information
Center (DIC), you may see the
voltage move up or down. This is
normal. If there is a problem, an
alert will be displayed.The battery can be discharged at
idle if the electrical loads are very
high. This is true for all vehicles.
This is because the generator
(alternator) may not be spinning fast
enough at idle to produce all of
the power needed for very high
electrical loads.
A high electrical load occurs when
several of the following are on, such
as: headlamps, high beams, fog
lamps, rear window defogger,
climate control fan at high speed,
heated seats, engine cooling fans,
trailer loads, and loads plugged into
accessory power outlets.
EPM works to prevent excessive
discharge of the battery. It does this
by balancing the generator's output
and the vehicle's electrical needs.
It can increase engine idle speed to
generate more power whenever
needed. It can temporarily reduce
the power demands of some
accessories.

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 (18,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-18 Driving and Operating
4.The resulting figure equals
the available amount of cargo
and luggage load capacity.
For example, if the“XXX”
amount equals 1400 lbs
and there will be five 150 lb
passengers in your vehicle,
the amount of available cargo
and luggage load capacity is
650 lbs (1400−750 (5x150) =
650 lbs).
5.Determine the combined
weight of luggage and cargo
being loaded on the vehicle.
That weight may not safely
exceed the available cargo
and luggage load capacity
calculated in Step 4.
6.If your vehicle will be towing
a trailer, the load from your
trailer will be transferred to
your vehicle. Consult this
manual to determine how this
reduces the available cargo
and luggage load capacity of your vehicle. See
Trailer
Towing on page 9‑78 for
important information on
towing a trailer, towing safety
rules and trailering tips.
Example 1
A. Vehicle Capacity Weight for Example 1 = (453 kg) (1,000 lbs)
B. Subtract Occupant Weight @ 68 kg (150 lbs) × 2 = 136 kg
(300 lbs)
C. Available Occupant and Cargo Weight = 317 kg (700 lbs)
Example 2
A. Vehicle Capacity Weight for Example 2 = 453 kg (1,000 lbs)
B. Subtract Occupant Weight @ 68 kg (150 lbs) × 5 = 340 kg
(750 lbs)
C. Available Cargo Weight = 113 kg (250 lbs)

Black plate (25,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-25
Starting and
Operating
New Vehicle Break-In
Notice:The vehicle does not
need an elaborate break-in. But it
will perform better in the long run
if you follow these guidelines:
.Keep the vehicle speed at
88 km/h (55 mph) or less for
the first 805 km (500 miles).
.Do not drive at any one
constant speed, fast or
slow, for the first 805 km
(500 miles). Do not make
full-throttle starts. Avoid
downshifting to brake or
slow the vehicle.
.Avoid making hard stops for
the first 322 km (200 miles) or
so. During this time the new
brake linings are not yet
broken in. Hard stops with
new linings can mean
premature wear and earlier replacement. Follow this
breaking-in guideline every
time you get new brake
linings.
.Do not tow a trailer during
break-in. See
Trailer Towing
on page 9‑78 for the trailer
towing capabilities of the
vehicle and more
information.
Following break‐in, engine
speed and load can be gradually
increased.
Adjustable Throttle and
Brake Pedal
On vehicles with this feature, you
can change the position of the
throttle and brake pedals.
No adjustment to the pedals can
be made when the vehicle is in
R (Reverse) or while using cruise
control.
The control used to adjust the
pedals is located on the instrument
panel below the climate control
system.
Press the bottom of the control to
move the pedals closer. Press the
top of the control to move the
pedals away.
Before you start driving, fully
press the brake pedal to confirm
the adjustment is right for you.
While driving, make only small
adjustments.
The vehicle may have a memory
function which lets pedal settings be
saved and recalled. See Memory
Seats on page 3‑7.

Black plate (31,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-31
WARNING (Continued)
gear—not in N (Neutral). If you
are pulling a trailer, see Driving
Characteristics and Towing Tips
on page 9‑74.
1. Hold the brake pedal down, then set the parking brake.
See Parking Brake on page 9‑54
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).
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).
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 9‑30.

Black plate (34,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-34 Driving and Operating
Running the Vehicle
While Parked
It is better not to park with the
engine running. But if you ever have
to, here are some things to know.
{WARNING
Idling a vehicle in an enclosed
area with poor ventilation is
dangerous. Engine exhaust may
enter the vehicle. Engine exhaust
contains carbon monoxide (CO)
which cannot be seen or smelled.
It can cause unconsciousness
and even death. Never run the
engine in an enclosed area that
has no fresh air ventilation. For
more information, seeEngine
Exhaust on page 9‑33.
{WARNING
It can be dangerous to get out
of the vehicle if the automatic
transmission 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).
{WARNING
Four-wheel drive vehicles with
the transfer case in N (Neutral)
will allow the vehicle to roll, even
if the automatic transmission
shift lever is in P (Park). So, be
sure the transfer case is in a drive
gear —not in N (Neutral). Always
set the parking brake.
Follow the proper steps to be sure
the vehicle will not move. See
Shifting Into Park on page 9‑30.
If pulling a trailer, see Driving
Characteristics and Towing Tips on
page 9‑74.