
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 (43,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Infotainment System 7-43
r(Fast Reverse):Press this
button to quickly reverse the DVD or
CD. To stop fast reversing a DVD
video, press the play/pause button.
To stop fast reversing a DVD audio
or CD, release the fast reverse
button. This button might not work
when the DVD is playing the
copyright information or the
previews.
[(Fast Forward): Press this
button to fast forward the DVD or
CD. To stop fast forwarding a DVD
video, press the play/pause button.
To stop fast forwarding a DVD audio
or CD, release the fast forward
button. This button might not work
while the DVD is playing the
copyright information or the
previews.
e(Audio): Press this button to
change audio tracks on DVDs that
have this feature when the DVD is
playing. The format and content of
this function vary for each disc.
{(Subtitles): Press this button to
turn on or off subtitles and to move
through subtitle options when a
DVD is playing. The format and
content of this function vary for
each disc.
AUX (Auxiliary): Press this button
to switch the system between the
DVD player and an auxiliary source.
2(Camera): Press this button to
change camera angles on DVDs
that have this feature while a DVD is
playing. The format and content of
this function vary for each disc.
1 through 0 (Numeric Keypad):
The numeric keypad provides the
capability of direct chapter or track
number selection.
\(Clear): Press this button within
three seconds after entering a
numeric selection, to clear all
numerical inputs.
}10 (Double Digit Entries): Press
this button to select chapter or track
numbers greater than nine. Press
this button before entering the
number.
Battery Replacement
To change the remote control
batteries, do the following:
1. Slide the rear cover back on the remote control.
2. Replace the two batteries in the compartment. Make sure they
are installed correctly using the
diagram on the inside of the
remote control.
3. Replace the battery cover.
If the remote control is to be stored
for a long period of time, remove the
batteries and keep them in a cool,
dry place.

Black plate (27,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-27
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
does not 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.
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.
A warning tone will sound when
the driver door is opened and 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: 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.
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: If you add electrical parts
or accessories, you could change
the way the engine operates. Any
resulting damage would not be
covered by the vehicle warranty.
See Add-On Electrical Equipment
on page 9‑105.

Black plate (28,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-28 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)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-32 Driving and Operating
When you are ready to drive, move
the shift lever out of P (Park) before
you release the parking brake.
If torque lock does occur, you may
need to have another vehicle push
yours a little uphill to take some of
the pressure from the parking pawl
in the transmission, then you will be
able to pull the shift lever out of
P (Park).
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 10‑88 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 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.
Active Fuel Management®
Vehicles with V8 engines may
have Active Fuel Management™.
This system allows the engine to
operate on either all or half of its
cylinders, depending on the driving
conditions.

Black plate (46,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-46 Vehicle Care
FusesUsage
9 Antilock Brakes System 2
10 Trailer Back-up Lamps
11 Driver Side Low-Beam
Headlamp
12 Engine Control Module
(Battery)
13 Fuel Injectors, Ignition
Coils (Right Side)
14 Transmission Control
Module (Battery)
15 Vehicle Back-up Lamps
16 Passenger Side
Low-Beam Headlamp
17 Air Conditioning
Compressor
18 Oxygen Sensors
19 Transmission Controls
(Ignition)
20 Fuel Pump
21 Fuel System Control
Module Fuses
Usage
22 Not Used
23 Not Used
24 Fuel Injectors, Ignition
Coils (Left Side)
25 Trailer Park Lamps
26 Driver Side Park Lamps
27 Passenger Side Park
Lamps
28 Fog Lamps
29 Horn
30 Passenger Side
High-Beam Headlamp
31 Daytime Running
Lamps (DRL)
32 Driver Side High-Beam
Headlamp
33 Daytime Running Lamps 2
34 Sunroof
35 Key Ignition System, Theft
Deterrent System Fuses
Usage
36 Windshield Wiper
37 SEO B2 Upfitter Usage
(Battery)
38 Electric Adjustable Pedals
39 Climate Controls (Battery)
40 Airbag System (Ignition)
41 Amplifier
42 Audio System
43 Miscellaneous (Ignition),
Cruise Control
44 Not Used
45 Airbag System (Battery)
46 Instrument Panel Cluster
47 Power Take-Off
48 Auxiliary Climate Control
(Ignition)
49 Center High-Mounted
Stoplamp (CHMSL)
50 Rear Defogger

Black plate (8,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
i-8 INDEX
LightsAirbag On-Off . . . . . . . . . . . . . . . . . 5-19
Airbag Readiness . . . . . . . . . . . . . 5-18
Antilock Brake System
(ABS) Warning . . . . . . . . . . . . . . 5-26
Brake System Warning . . . . . . . 5-25
Charging System . . . . . . . . . . . . . 5-22
Cruise Control . . . . . . . . . . . . . . . . 5-30
Engine Oil Pressure . . . . . . . . . . 5-28
Flash-to-Pass . . . . . . . . . . . . . . . . . . 6-3
Four-Wheel-Drive . . . . . . . . . . . . . 5-26
Front Fog Lamp . . . . . . . . . . . . . . 5-29
High-Beam On . . . . . . . . . . . . . . . . 5-29
High/Low Beam Changer . . . . . . 6-3
Low Fuel Warning . . . . . . . . . . . . 5-28
Safety Belt Reminders . . . . . . . . 5-17
Security . . . . . . . . . . . . . . . . . . . . . . 5-29
StabiliTrak
®OFF . . . . . . . . . . . . . 5-27
Tire Pressure . . . . . . . . . . . . . . . . . 5-27
Tow/Haul Mode . . . . . . . . . . . . . . . 5-26
Traction Control System (TCS)/StabiliTrak
®. . . . . . . . . . 5-27
Locking Rear Axle . . . . . . . . . . . . . 9-58 Locks
Automatic Door . . . . . . . . . . . . . . . . 2-8
Delayed Locking . . . . . . . . . . . . . . . 2-8
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Lockout Protection . . . . . . . . . . . . . 2-9
Power Door . . . . . . . . . . . . . . . . . . . . 2-8
Safety . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Loss of Control . . . . . . . . . . . . . . . . . 9-5
Low Fuel Warning Light . . . . . . . . 5-28
Lower Anchors and Tethers for Children (LATCH
System) . . . . . . . . . . . . . . . . . . . . . . 3-47
Lumbar Adjustment . . . . . . . . . . . . . 3-4 Front Seats . . . . . . . . . . . . . . . . . . . . 3-4
M
MaintenanceRecords . . . . . . . . . . . . . . . . . . . . .11-16
Maintenance Schedule Recommended Fluidsand Lubricants . . . . . . . . . . . . .11-12
Transfer Case . . . . . . . . . . . . . . . . 9-40
Malfunction Indicator Lamp . . . . 5-22
Manual Mirrors . . . . . . . . . . . . . . . . 2-14 Manual Mode . . . . . . . . . . . . . . . . . . 9-38
Manual Windows . . . . . . . . . . . . . . 2-19
Memory Features . . . . . . . . . . . . . . 1-14
Memory Seats . . . . . . . . . . . . . . . . . . 3-7
Messages
Airbag System . . . . . . . . . . . . . . . . 5-45
Anti-theft Alarm System . . . . . . . 5-45
Battery Voltage andCharging . . . . . . . . . . . . . . . . . . . . 5-39
Brake System . . . . . . . . . . . . . . . . 5-40
Door Ajar . . . . . . . . . . . . . . . . . . . . . 5-40
Engine Cooling System . . . . . . . 5-41
Engine Oil . . . . . . . . . . . . . . . . . . . . 5-42
Engine Power . . . . . . . . . . . . . . . . 5-42
Fuel System . . . . . . . . . . . . . . . . . . 5-43
Key and Lock . . . . . . . . . . . . . . . . . 5-43
Lamp . . . . . . . . . . . . . . . . . . . . . . . . . 5-43
Object Detection System . . . . . 5-43
Ride Control System . . . . . . . . . . 5-44
Starting the Vehicle . . . . . . . . . . . 5-45
Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-45
Transmission . . . . . . . . . . . . . . . . . 5-46
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 5-39
Vehicle Reminder . . . . . . . . . . . . . 5-47
Washer Fluid . . . . . . . . . . . . . . . . . 5-48

Black plate (10,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
i-10 INDEX
ParkingAssist, Ultrasonic . . . . . . . . . . . . . 9-61
Brake . . . . . . . . . . . . . . . . . . . . . . . . . 9-54
Brake and P (Park)
Mechanism Check . . . . . . . . 10-36
Over Things That Burn . . . . . . . 9-32
Passenger Airbag Status
Indicator . . . . . . . . . . . . . . . . . . . . . 5-21
Passenger Sensing System . . . 3-32
Perchlorate Materials Requirements, California . . . . . 10-3
Personalization Vehicle . . . . . . . . . . . . . . . . . . . . . . . 5-48
Phone Bluetooth . . . . . . . . . . . . . . . . . . . . . 7-48
Pick-up Box Identification
and Fender Marker
Lamps . . . . . . . . . . . . . . . . . . . . . . 10-40
Pickup Conversion to Chassis Cab . . . . . . . . . . . . . . . . 9-109
Power
Door Locks . . . . . . . . . . . . . . . . . . . . 2-8
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . 2-15
Outlets . . . . . . . . . . . . . . . . . . . . . . . . 5-9
Protection, Battery . . . . . . . . . . . . 6-10
Retained Accessory (RAP) . . . 9-29 Power (cont'd)
Seat Adjustment . . . . . . . . . . . . . . . 3-4
Steering Fluid . . . . . . . . . . . . . . . 10-25
Windows . . . . . . . . . . . . . . . . . . . . . 2-20
Pregnancy, Using Safety Belts . . . . . . . . . . . . . . . . . . . . . . . . . 3-19
Privacy Radio FrequencyIdentification (RFID) . . . . . . . 13-20
Program Courtesy Transportation . . . . 13-13
Proposition 65 Warning, California . . . . . . . . . . . . . . . . . . . . . 10-3
R
Radio FrequencyIdentification (RFID) . . . . . . . . 13-20
Statement . . . . . . . . . . . . . . . . . . 13-20
Radios AM-FM Radio . . . . . . . . . . . . . . . . . . 7-9
CD/DVD Player . . . . . . . . . . . . . . . 7-21
Reception . . . . . . . . . . . . . . . . . . . . 7-14
Satellite . . . . . . . . . . . . . . . . . . . . . . . 7-11
Reading Lamps . . . . . . . . . . . . . . . . . 6-8
Rear Axle . . . . . . . . . . . . . . . . . . . . . 10-32 Locking . . . . . . . . . . . . . . . . . . . . . . . 9-58 Rear Doors . . . . . . . . . . . . . . . . . . . . . 2-9
Rear Seat Audio (RSA)
System . . . . . . . . . . . . . . . . . . . . . . . 7-46
Rear Seat Entertainment System . . . . . . . . . . . . . . . . . . . . . . . 7-37
Rear Seat Audio (RSA) . . . . . . . 7-46
Rear Seats . . . . . . . . . . . . . . 3-10, 3-11
Rear Vision Camera (RVC) . . . . 9-62
Rear Windows . . . . . . . . . . . . . . . . . 2-21
Rearview Mirrors . . . . . . . . . . . . . . 2-18 Automatic Dimming . . . . . . . . . . . 2-18
Reclining Seatbacks . . . . . . . . . . . . 3-5
Recommended Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 9-68
Recommended Fluids and Lubricants . . . . . . . . . . . . . . . . . . . 11-12
Records Maintenance . . . . . . . . . . . . . . . . .11-16
Recreational Vehicle Towing . . . . . . . . . . . . . . . . . . . . . . 10-93
Reimbursement Program,
GM Mobility . . . . . . . . . . . . . . . . . . 13-7
Remote Keyless Entry (RKE) System . . . . . . . . . . . . . 2-2, 2-3
Remote Vehicle Start . . . . . . . . . . . 2-5