2012 GMC SIERRA 1500 towing

Black plate (23,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Instruments and Controls 5-23
If the malfunction indicator lamp
comes on and stays on while the
engine is running, this indicates that
there is an OBD II problem and
service is required.
Malfunctions often are indicated by
the system before any problem is
apparent. Being aware of the light
can prevent more serious damage
to the vehicle. This system assists
the service technician in correctly
diagnosing any malfunction.
Notice:If the vehicle is
continually driven with this light
on, the emission controls might
not work as well, the vehicle fuel
economy might not be as good,
and the engine might not run as
smoothly. This could lead to
costly repairs that might not be
covered by the vehicle warranty. Notice:
Modifications made
to the engine, transmission,
exhaust, intake, or fuel system
of the vehicle or the replacement
of the original tires with other
than those of the same Tire
Performance Criteria (TPC) can
affect the vehicle's emission
controls and can cause this light
to come on. Modifications to
these systems could lead to
costly repairs not covered by
the vehicle warranty. This could
also result in a failure to pass a
required Emission Inspection/
Maintenance test. See
Accessories and Modifications on
page 10‑3.
This light comes on during a
malfunction in one of two ways:
Light Flashing: A misfire condition
has been detected. A misfire
increases vehicle emissions and
could damage the emission control
system on the vehicle. Diagnosis
and service might be required. To prevent more serious damage to
the vehicle:
.Reduce vehicle speed.
.Avoid hard accelerations.
.Avoid steep uphill grades.
.If towing a trailer, reduce the
amount of cargo being hauled as
soon as it is possible.
If the light continues to flash, stop
and park the vehicle. Turn the
vehicle off, wait at least 10 seconds,
and restart the engine. If the light is
still flashing, follow the previous
steps and see your dealer for
service as soon as possible.
Light On Steady: An emission
control system malfunction has
been detected on the vehicle.
Diagnosis and service might be
required.

Black plate (25,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Instruments and Controls 5-25
The vehicle would be considered
not ready for inspection. This
can happen if the 12-volt battery
has recently been replaced or
run down. The diagnostic system
is designed to evaluate critical
emission control systems during
normal driving. This can take
several days of routine driving.
If this has been done and the
vehicle still does not pass the
inspection for lack of OBD II
system readiness, your dealer
can prepare the vehicle for
inspection.
Brake System Warning
Light
With the ignition on, the brake
system warning light comes on
when the parking brake is set. If the
vehicle is driven with the parking
brake engaged, a chime sounds
when the vehicle speed is greater
than 8 km/h (5 mph).The vehicle brake system consists
of two hydraulic circuits. If one
circuit is not working, the remaining
circuit can still work to stop the
vehicle. For normal braking
performance, both circuits need to
be working.
If the warning light comes on and a
chime sounds there could be a
brake problem. Have the brake
system inspected right away.
This light can also come on due to
low brake fluid. See
Brake Fluid on
page 10‑28 for more information.
MetricEnglish
This light comes on briefly when the
ignition key is turned to ON/RUN.
If it does not come on then, have it
fixed so it is ready to warn if there is
a problem.
{WARNING
The brake system might not be
working properly if the brake
system warning light is on.
Driving with the brake system
warning light on can lead to a
crash. If the light is still on after
the vehicle has been pulled off
the road and carefully stopped,
have the vehicle towed for
service.
If the light comes on while driving,
pull off the road and stop carefully.
The pedal might be harder to push
or might go closer to the floor. It can
take longer to stop. If the light is
still on, have the vehicle towed for
service. See Towing the Vehicle on
page 10‑93.
If the vehicle is a hybrid, see the
hybrid supplement for more
information.

Black plate (35,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Instruments and Controls 5-35
Trailer Gain and Output
On vehicles with the Integrated
Trailer Brake Control (ITBC) system,
the trailer brake display appears
in the DIC. Press the vehicle
information button 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.
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).
Engine Hours
Press the vehicle information button
until ENGINE HOURS displays. This
display shows the total number of
hours the engine has run.
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. Blank Display
This display shows no information.
Trip Odometer Reset Stem
Menu Items (with DIC Buttons)
Use the trip odometer reset stem
to view the odometer and trip
odometer. The Language selection
and Engine Hours display can also
be accessed with the trip odometer
reset stem.
Odometer
Press the trip odometer reset stem
until ODOMETER displays. This
display shows the distance the
vehicle has been driven in either
kilometers (km) or miles (mi).
Trip Odometer
Press the trip odometer reset stem
until TRIP displays. This display
shows the current distance
traveled in either kilometers (km) or
miles (mi) since the last reset for the
trip odometer.

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 (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.