
Black plate (2,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
2012 GMC Sierra Owner ManualM
Ride Control Systems . . . . . . . . 9-55
Cruise Control . . . . . . . . . . . . . . . . 9-58
Object Detection Systems . . . . 9-61
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 9-68
Towing . . . . . . . . . . . . . . . . . . . . . . . 9-74
Conversions and
Add-Ons . . . . . . . . . . . . . . . . . . . 9-105
Vehicle Care . . . . . . . . . . . . . . . . . 10-1
General Information . . . . . . . . . . 10-2
Vehicle Checks . . . . . . . . . . . . . . . 10-4
Headlamp Aiming . . . . . . . . . . . 10-37
Bulb Replacement . . . . . . . . . . 10-39
Electrical System . . . . . . . . . . . . 10-43
Wheels and Tires . . . . . . . . . . . 10-50
Jump Starting . . . . . . . . . . . . . . . 10-88
Towing . . . . . . . . . . . . . . . . . . . . . . 10-93
Appearance Care . . . . . . . . . . . 10-98 Service and Maintenance
. . . 11-1
General Information . . . . . . . . . . 11-1
Maintenance Schedule . . . . . . . 11-3
Special Application
Services . . . . . . . . . . . . . . . . . . . . 11-8
Additional Maintenance and Care . . . . . . . . . . . . . . . . . . . . 11-9
Recommended Fluids,
Lubricants, and Parts . . . . . . 11-12
Maintenance Records . . . . . . . 11-16
Technical Data . . . . . . . . . . . . . . . 12-1
Vehicle Identification . . . . . . . . . 12-1
Vehicle Data . . . . . . . . . . . . . . . . . . 12-2 Customer Information
. . . . . . . 13-1
Customer Information . . . . . . . . 13-1
Reporting Safety Defects . . . . 13-17
Vehicle Data Recording and
Privacy . . . . . . . . . . . . . . . . . . . . 13-19
OnStar . . . . . . . . . . . . . . . . . . . . . . . 14-1
OnStar Overview . . . . . . . . . . . . . 14-1
OnStar Services . . . . . . . . . . . . . . 14-2
OnStar Additional
Information . . . . . . . . . . . . . . . . . . 14-5
Index . . . . . . . . . . . . . . . . . . . . . i-1

Black plate (3,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Introduction iii
The names, logos, emblems,
slogans, vehicle model names, and
vehicle body designs appearing in
this manual including, but not limited
to, GM, the GM logo, GMC, the
GMC Truck Emblem, and SIERRA
are trademarks and/or service
marks of General Motors LLC, its
subsidiaries, affiliates, or licensors.
This manual describes features that
may or may not be on your specific
vehicle either because they are
options that you did not purchase
or due to changes subsequent to
the printing of this owner manual.Please refer to the purchase
documentation relating to your
specific vehicle to confirm each of
the features found on your vehicle.
For vehicles first sold in Canada,
substitute the name
“General
Motors of Canada Limited” for GMC
Division wherever it appears in this
manual.
If the vehicle has the Duramax
®
diesel engine, see the Duramax
diesel supplement for additional and
specific information on this engine.
If the vehicle is a hybrid, see
the hybrid supplement for more
information.
Keep this manual in the vehicle for
quick reference.
Canadian Vehicle Owners
Propriétaires Canadiens
A French language copy of this
manual can be obtained from your
dealer or from:
On peut obtenir un exemplaire de
ce guide en français auprès du
concessionnaire ou à l'adresse
suivante:
Helm, Incorporated
Attention: Customer Service
47911 Halyard Drive
Plymouth, MI 48170
Litho in U.S.A.
Part No. 20902916 B Second Printing©2011 General Motors LLC. All Rights Reserved.

Black plate (4,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
iv Introduction
Using this Manual
To quickly locate information
about the vehicle, use the Index in
the back of the manual. It is an
alphabetical list of what is in the
manual and the page number where
it can be found.
Danger, Warnings, and
Cautions
Warning messages found on vehicle
labels and in this manual describe
hazards and what to do to avoid or
reduce them.
Dangerindicates a hazard with a
high level of risk which will result in
serious injury or death.
Warning orCaution indicates a
hazard that could result in injury or
death.
{WARNING
These mean there is something
that could hurt you or other
people.
Notice: This means there is
something that could result in
property or vehicle damage. This
would not be covered by the
vehicle's warranty.
A circle with a slash through it is a
safety symbol which means “Do
Not,” “Do not do this,” or“Do not let
this happen.”
Symbols
The vehicle has components and
labels that use symbols instead of
text. Symbols are shown along with
the text describing the operation or
information relating to a specific
component, control, message,
gauge, or indicator.
M: This symbol is shown when
you need to see your owner manual
for additional instructions or
information.
*: This symbol is shown when
you need to see a service manual
for additional instructions or
information.

Black plate (28,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
1-28 In Brief
Storing Radio Stations
A maximum of 36 stations can be
stored as favorites using the six
softkeys located below the radio
station frequency tabs and by using
the radio FAV button. Press FAV to
go through up to six pages of
favorites, each having six favorite
stations available per page. Each
page of favorites can contain any
combination of AM, FM, or XM
stations.
For more information, see“Storing
Radio Stations” inAM-FM Radio on
page 7‑9.
Setting the Clock
To set the time and date:
1. Turn the ignition key to ACC/
ACCESSORY or ON/RUN, then
press
O, to turn the radio on.
2. Press
Hto display HR, MIN,
MM, DD, and YYYY (hour,
minute, month, day, and year). 3. Press the softkey located under
any one of the labels to be
changed.
4. To increase or decrease the time or date, turn
fclockwise or
counter‐clockwise.
For detailed instructions on setting
the clock for the vehicle's specific
audio system, see Clock on
page 5‑7.
Satellite Radio
XM is a satellite radio service based
in the 48 contiguous United States
and 10 Canadian provinces.
XM satellite radio has a wide
variety of programming and
commercial-free music, coast to
coast, and in digital-quality sound. A fee is required to receive the
XM service.
For more information, refer to:
.www.xmradio.com or call
1-800-929-2100 (U.S.)
.www.xmradio.ca or call
1-877-438-9677 (Canada)
See Satellite Radio on page 7‑11.
Portable Audio Devices
This vehicle may have an auxiliary
input located on the radio faceplate
and a USB port located in the center
console or on the instrument panel.
External devices such as an iPod
®,
laptop computer, MP3 player, CD
changer, or USB storage device can
be connected to the auxiliary port
using a 3.5 mm (1/8 in) input cable
or the USB port depending on the
audio system.
See “Using the Auxiliary Input
Jack” and“Using the USB Port” in
Auxiliary Devices on page 7‑32.

Black plate (37,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
In Brief 1-37
As the owner of a new GMC, you
are automatically enrolled in the
Roadside Assistance program.
SeeRoadside Assistance Program
(U.S. and Canada) on page 13‑7 or
Roadside Assistance Program
(Mexico) on page 13‑9.
Roadside Assistance and OnStar
(U.S. and Canada)
If you have an active OnStar
subscription, press the
Qbutton
and the current GPS location will
be sent to an OnStar advisor who
will assess your problem, contact
Roadside Assistance, and relay
your exact location to get the help
you need. Online Owner Center (U.S. and
Canada)
The Online Owner Center is a
complimentary service that includes
online service reminders, vehicle
maintenance tips, online owner
manual, special privileges,
and more.
Sign up today at:
U.S.: gmc.com (click on
“Owners,”
then“Manage My
GMC/Owners Login”)
Canada: gmcowner.ca
OnStar®
If equipped, this vehicle has a
comprehensive, in-vehicle system
that can connect to a live Advisor
for Emergency, Security, Navigation,
Connection, and Diagnostic
Services. See OnStar Overview on
page 14‑1.

Black plate (3,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Keys, Doors, and Windows 2-3
If there is a decrease in the RKE
operating range:
.Check the distance. The
transmitter may be too far from
the vehicle.
.Check the location. Other
vehicles or objects may be
blocking the signal.
.Check the transmitter's battery.
See“Battery Replacement” later
in this section.
.If the transmitter is still not
working correctly, see your
dealer or a qualified technician
for service.
Remote Keyless Entry
(RKE) System Operation
The Remote Keyless Entry (RKE)
transmitter functions work up to
60 m (195 ft) away from the vehicle.
There are other conditions which
can affect the performance of the
transmitter. See Remote Keyless
Entry (RKE) System on page 2‑2.
With Remote Start (without
Remote Start Similar)
/(Remote Vehicle Start): For
vehicles with this feature, press
/
to start the engine from outside the
vehicle using the RKE transmitter.
See Remote Vehicle Start on
page 2‑5 for additional information.
Q(Lock):Press to lock all the
doors.
If enabled through the Driver
Information Center (DIC), the turn
signal lamps flash once to indicate
locking has occurred. If enabled
through the DIC, the horn chirps when
Qis pressed again within
three seconds. See Vehicle
Personalization (With DIC Buttons)
on page 5‑48 for additional
information.
Pressing
Qarms the content
theft‐deterrent system. See
Anti-theft Alarm System on
page 2‑11.
K(Unlock): Press once to unlock
only the driver door. If
Kis pressed
again within three seconds, all
remaining doors unlock. The interior
lamps may come on and stay on for
20 seconds or until the ignition is
turned on.
If enabled through the DIC, the turn
signal lamps flash twice to indicate
unlocking has occurred. See Vehicle
Personalization (With DIC Buttons)
on page 5‑48. If enabled through the
DIC, the exterior lights may turn on.
See “Approach Lighting” under
Vehicle Personalization (With DIC
Buttons) on page 5‑48.

Black plate (12,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
2-12 Keys, Doors, and Windows
If the delayed locking feature is
active, the alarm will not be
activated until all doors are
closed and the security light
goes off.
3. Close all doors. The security light will stop flashing and go off
after approximately 30 seconds.
The system is armed when the
security light goes off.
If a locked driver door is opened
without using the RKE transmitter, a
10 second pre-alarm will occur. The
horn will chirp and the lights will
flash. If the key is not placed in the
ignition and turned to START or the
door is not unlocked by pressing
the unlock button on the RKE
transmitter during the 10 second
pre-alarm, the alarm will go off.
The vehicle's headlamps will flash
and the horn will sound for about
30 seconds, then will turn off to save
the battery power.
The theft-deterrent system will not
activate if the doors are locked with
the key or the manual door lock. It activates only if you use the
power door lock switch or the RKE
transmitter. The vehicle can be
started with the correct key if the
alarm is set off.
To avoid setting off the alarm by
accident:
.If you do not want to activate
the theft-deterrent system, the
vehicle should be locked with
the door key after the doors are
closed.
.Always unlock a door with the
RKE transmitter.
If the alarm is set off, press unlock
on the RKE transmitter or place the
key in the ignition and turn it to
START.
Testing the Alarm
To test the alarm:
1. Lower the driver window and open the driver door.
2. Press lock on the RKE transmitter. 3. Close the door and wait for the
security light to go out.
4. Reach in through the window, unlock the door with the manual
door lock, and open the door.
This should set off the alarm.
If the alarm does not sound when it
should but the headlamps flash,
check to see if the horn works. The
horn fuse may be blown. To replace
the fuse, see Fuses and Circuit
Breakers on page 10‑44.
If the alarm does not sound or the
headlamps do not flash, see your
dealer for service.
Immobilizer
See Radio Frequency Statement on
page 13‑20 for information
regarding Part 15 of the Federal
Communications Commission (FCC)
rules and Industry Canada
Standards RSS-GEN/210/220/310.

Black plate (13,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Keys, Doors, and Windows 2-13
Immobilizer Operation
This vehicle has PASS-Key®III+
(Personalized Automotive Security
System) theft-deterrent system.
PASS-Key III+ is a passive
theft-deterrent system.
The system is automatically armed
when the key is removed from the
ignition.
The system is automatically
disarmed when the key is turned
to ON/RUN, ACC/ACCESSORY,
or START from the LOCK/OFF
position.
You do not have to manually arm or
disarm the system.
The security light will come on if
there is a problem with arming or
disarming the theft-deterrent
system.
When the PASS-Key III+ system
senses that someone is using the
wrong key, it prevents the vehicle
from starting. Anyone using a
trial-and-error method to start the vehicle will be discouraged because
of the high number of electrical key
codes.
If the engine does not start and the
security light on the instrument
panel cluster comes on when trying
to start the vehicle, there may be a
problem with the theft-deterrent
system. Turn the ignition off and try
again.
If the engine still does not start, and
the key appears to be undamaged,
try another ignition key. At this time,
you may also want to check the
fuse. See
Fuses and Circuit
Breakers on page 10‑44. If the
engine still does not start with the
other key, the vehicle needs service.
If the vehicle does start, the first key
may be faulty. See your dealer who
can service the PASS-Key III+ to
have a new key made.
It is possible for the PASS-Key III+
decoder to learn the transponder
value of a new or replacement key.
Up to 10 keys may be programmed for the vehicle. The following
procedure is for programming
additional keys only. If all the
currently programmed keys are lost
or do not operate, you must see
your dealer or a locksmith who can
service PASS-Key III+ to have keys
made and programmed to the
system.
See your dealer or a locksmith who
can service PASS-Key III+ to get a
new key blank cut exactly as the
ignition key that operates the
system.
To program the new additional key:
1. Verify that the new key has
a
1stamped on it.
2. Insert the original, already programmed key in the ignition
and start the engine. If the
engine will not start, see your
dealer for service.
3. After the engine has started, turn the key to LOCK/OFF, and
remove the key.