2012 GMC SIERRA 1500 AUX

Black plate (96,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-96 Driving and Operating
Be sure to follow the proper
installation instructions included
with any electrical equipment that is
installed.
Notice:Leaving electrical
equipment on for extended
periods will drain the battery.
Always turn off electrical
equipment when not in use and
do not use equipment that
exceeds the maximum amperage
rating of 40 amperes for the
auxiliary battery provision.
Trailer Wiring Harness
The vehicle is equipped with one of
the following wiring harnesses for
towing a trailer or hauling a slide-in
camper. Basic Trailer Wiring
All regular, extended cab and crew
cab pickups have a seven-wire
trailer towing harness.
For vehicles not equipped with
heavy duty trailering, the harness
is secured to the vehicle's frame
behind the spare tire mount. The
harness requires the installation of a
trailer connector, which is available
through your dealer.
If towing a light-duty trailer with
a standard four-way round pin
connector, an adapter is available
from your dealer.
Heavy-DutyTrailer Wiring Harness
PackageFor vehicles equipped with
heavy duty trailering, the harness
connector is mounted in the bumper.
The seven-wire harness contains
the following trailer circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn
Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps

Black plate (97,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-97
.Red: Battery Feed*
.Dark Blue: Trailer Brake*
*The fuses for these two circuits are
installed in the underhood electrical
center, but the wires are not
connected. They should be
connected by your dealer or a
qualified service center. The fuse
and wire for the ITBC is factory
installed and connected if the
vehicle is equipped with an ITBC.
The fuse for the battery feed is not
required if the vehicle has an
auxiliary battery. If the vehicle does
not have an auxiliary battery, have
your dealer or authorized service
center install the required fuse.
If charging a remote (non-vehicle)
battery, press the Tow/Haul Mode
button, if equipped, located at
the end of the shift lever. This will
boost the vehicle system voltage
and properly charge the battery.
If the trailer is too light for Tow/
Haul Mode, or the vehicle is not
equipped with Tow/Haul, turn on the headlamps as a second way to
boost the vehicle system and
charge the battery.
Camper/Fifth-Wheel Trailer Wiring
Package
The seven-wire camper harness is
located under the front edge of the
pickup box on the driver side of
the vehicle, attached to the frame
bracket. A connector must be
added to the wiring harness which
connects to the camper.
The harness contains the following
camper/trailer circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn
Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red: Battery Feed
.Dark Blue: Trailer Brake
If the vehicle is equipped with the
“Heavy-Duty Trailering”
option,
please refer to “Heavy-Duty Trailer
Wiring Package” earlier in this
section.
When the camper-wiring harness
is ordered without the heavy-duty
trailering package, a seven-wire
harness with a seven-pin connector
is located at the rear of the vehicle
and is tied to the vehicle's frame.

Black plate (109,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-109
See your dealer for additional
advice and information about using
a snow plow on the vehicle. Also,
seeVehicle Load Limits on
page 9‑16.
Emergency Roof Lamp
Provisions
Vehicles with the RPO VYU snow
plow prep package also have an
emergency roof lamp provision
package, RPO TRW. Wiring for the
emergency roof lamp is provided
above the overhead console. See
Auxiliary Roof-Mounted Lamp on
page 6‑6 for switch location.
Pickup Conversion to
Chassis Cab
We are aware that some vehicle
owners might consider having the
pickup box removed and a
commercial or recreational body
installed. Owners should be aware
that, as manufactured, there are
differences between a chassis cab
and a pickup with the box removed
which could affect vehicle safety.
The components necessary to adapt
a pickup to permit its safe use with
a specialized body should be
installed by the body builder.

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 (90,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-90 Vehicle Care
If your vehicle has a gasoline
engine, the remote negative (-)
terminal is a stud located on the
right front of the engine, where
the negative battery cable
attaches.
If your vehicle has a diesel
engine, the remote negative (-)
terminal is the negative (-) post
on the auxiliary battery on the
driver side of the engine
compartment.For more information on
the location of the remote
positive (+) and remote
negative (−) terminals, see
Engine Compartment Overview
on page 10‑6
{WARNING
An electric fan can start up even
when the engine is not running
and can injure you. Keep hands,
clothing and tools away from any
underhood electric fan.
{WARNING
Using an open flame near a
battery can cause battery gas to
explode. People have been hurt
doing this, and some have been
blinded. Use a flashlight if you
need more light.
(Continued)
WARNING (Continued)
Be sure the battery has enough
water. You do not need to add
water to the battery installed in
your new vehicle. But if a battery
has filler caps, be sure the right
amount of fluid is there. If it is low,
add water to take care of that
first. If you do not, explosive gas
could be present.
Battery fluid contains acid that
can burn you. Do not get it on
you. If you accidentally get it in
your eyes or on your skin, flush
the place with water and get
medical help immediately.

Black plate (2,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
i-2 INDEX
Automatic TransmissionManual Mode . . . . . . . . . . . . . . . . . 9-38
Shift Lock Control
Function Check . . . . . . . . . . . 10-35
Auxiliary Devices . . . . . . . . . . . . . . . . . . . . . . . 7-32
Roof Mounted Lamp . . . . . . . . . . . 6-6
Axle, Front . . . . . . . . . . . . . . . . . . . . 10-31
Axle, Rear . . . . . . . . . . . . . . . . . . . . 10-32
B
Battery . . . . . . . . . . . . . . . . . . . . . . . 10-30 Jump Starting . . . . . . . . . . . . . . . 10-88
Load Management . . . . . . . . . . . . . 6-9
Power Protection . . . . . . . . . . . . . 6-10
Voltage and Charging
Messages . . . . . . . . . . . . . . . . . . . 5-39
Blade Replacement, Wiper . . . 10-36
Bluetooth . . . . . . . . . . . . . . . . . . . . . . 7-48
Brake
Pedal and AdjustableThrottle . . . . . . . . . . . . . . . . . . . . . . 9-25
System Warning Light . . . . . . . . 5-25 Brakes . . . . . . . . . . . . . . . . . . . . . . . . 10-27
Antilock . . . . . . . . . . . . . . . . . . . . . . . 9-53
Assist . . . . . . . . . . . . . . . . . . . . . . . . . 9-54
Fluid . . . . . . . . . . . . . . . . . . . . . . . . 10-28
Parking . . . . . . . . . . . . . . . . . . . . . . . 9-54
System Messages . . . . . . . . . . . . 5-40
Braking . . . . . . . . . . . . . . . . . . . . . . . . . 9-4
Break-In, New Vehicle . . . . . . . . . 9-25
Bulb Replacement . . . . . . . . . . . . 10-43
Center High-MountedStoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . 10-42
Fog Lamps . . . . . . . . . . . . . . . . . . . . 6-6
Halogen Bulbs . . . . . . . . . . . . . . 10-39
Headlamp Aiming . . . . . . . . . . . 10-37
Headlamps . . . . . . . . . . . . . . . . . 10-39
Headlamps, Front Turn Signal, Sidemarker, and
Parking Lamps . . . . . . . . . . . . 10-39
License Plate Lamps . . . . . . . 10-42 Bulb Replacement (cont'd)
Pick-up Box Identification
and Fender Marker
Lamps . . . . . . . . . . . . . . . . . . . . 10-40
Taillamps . . . . . . . . . . . . . . . . . . . 10-40
Taillamps, Turn Signal, Stoplamps, and
Back-up Lamps . . . . . . . . . . . 10-41
Buying New Tires . . . . . . . . . . . . . 10-68
C
Calibration . . . . . . . . . . . . . . . . . . . . . . 5-5
California
Fuel Requirements . . . . . . . . . . . 9-69
Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . 10-3
Warning . . . . . . . . . . . . . . . . . . . . . . 10-3
Camera, Rear Vision . . . . . . . . . . 9-62
Canadian Vehicle Owners . . . . . . . . iii
Capacities and Specifications . . . . . . . . . . . . . . . . 12-2

Black plate (4,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
i-4 INDEX
D
Damage Repair, Collision . . . . . 13-14
Danger, Warnings, andCautions . . . . . . . . . . . . . . . . . . . . . . . . iv
Data Recorders, Event . . . . . . . 13-19
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . . . 6-3
Defensive Driving . . . . . . . . . . . . . . . 9-3
Delayed Locking . . . . . . . . . . . . . . . . 2-8
Devices, Auxiliary . . . . . . . . . . . . . 7-32
Diagnostics, OnStar
®. . . . . . . . . . 14-5
Distracted Driving . . . . . . . . . . . . . . . 9-2
Dome Lamps . . . . . . . . . . . . . . . . . . . 6-8
Door Ajar Messages . . . . . . . . . . . . . . . 5-40
Delayed Locking . . . . . . . . . . . . . . . 2-8
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Power Locks . . . . . . . . . . . . . . . . . . . 2-8
Rear Doors . . . . . . . . . . . . . . . . . . . . 2-9
Drive Belt Routing, Engine . . . . . 12-6
Driver Information
Center (DIC) . . . . . . . . . . . . . . . . . 5-30 Driving
Characteristics and
Towing Tips . . . . . . . . . . . . . . . . . 9-74
Defensive . . . . . . . . . . . . . . . . . . . . . . 9-3
Drunk . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3
For Better Fuel Economy . . . . . 1-36
Highway Hypnosis . . . . . . . . . . . . 9-12
Hill and Mountain Roads . . . . . . 9-12
If the Vehicle is Stuck . . . . . . . . . 9-15
Loss of Control . . . . . . . . . . . . . . . . 9-5
Off-Road . . . . . . . . . . . . . . . . . . . . . . 9-6
Off-Road Recovery . . . . . . . . . . . . 9-5
Vehicle Load Limits . . . . . . . . . . . 9-16
Wet Roads . . . . . . . . . . . . . . . . . . . 9-11
Winter . . . . . . . . . . . . . . . . . . . . . . . . 9-13
Dual Automatic Climate
Control System . . . . . . . . . . . . . . . . 8-5
Dual Tire Rotation . . . . . . . . . . . . . . . . . . . . 10-67
DVD Rear Seat Entertainment
System . . . . . . . . . . . . . . . . . . . . . . 7-37
DVD/CD Player . . . . . . . . . . . . . . . . 7-21
E
E85 Fuel . . . . . . . . . . . . . . . . . . . . . . . 9-71
Electrical Equipment, Add-On . . . . . . . . . . . . . . . . . . . . . 9-105
Electrical System Engine CompartmentFuse Block . . . . . . . . . . . . . . . . 10-44
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-44
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . 10-48
Overload . . . . . . . . . . . . . . . . . . . 10-43
Emergency, OnStar
®. . . . . . . . . . 14-2
Engine Air Cleaner/Filter . . . . . . . . . . . 10-17
Check and Service EngineSoon Light . . . . . . . . . . . . . . . . . . 5-22
Compartment Overview . . . . . . . 10-6
Coolant . . . . . . . . . . . . . . . . . . . . . 10-19
Coolant Heater . . . . . . . . . . . . . . . 9-30
Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . 5-16
Cooling System . . . . . . . . . . . . . 10-18

Black plate (7,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
INDEX i-7
Heating and AirConditioning . . . . . . . . . . . . . . . 8-1, 8-4
High-Beam On Light . . . . . . . . . . . 5-29
High-Speed Operation . . . . . . . . 10-60
Highway Hypnosis . . . . . . . . . . . . . 9-12
Hill and Mountain Roads . . . . . . . 9-12
Hill Start Assist (HSA) . . . . . . . . . 9-54
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
How to Wear Safety Belts Properly . . . . . . . . . . . . . . . . . . . . . . 3-13
I
Idle System
Fast . . . . . . . . . . . . . . . . . . . . . . . . . . 9-29
Ignition Positions . . . . . . . . . . . . . . 9-26
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 10-35
Immobilizer . . . . . . . . . . . . . . . . . . . . 2-12
Infants and Young Children, Restraints . . . . . . . . . . . . . . . . . . . . 3-41
Infotainment . . . . . . . . . . . . . . . . . . . . 7-1 Instrument Cluster . . . . . . . . . . . . . 5-12
Instrument Panel
Storage Area . . . . . . . . . . . . . . . . . . 4-1
Introduction . . . . . . . . . . . . . . . . . . . . . . . iii
J
Jump Starting . . . . . . . . . . . . . . . . . 10-88
K
Key and Lock Messages . . . . . . . 5-43
Keyless Entry Remote (RKE) System . . . . . . . . 2-3
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
L
Labeling, Tire Sidewall . . . . . . . . 10-52
Lamps Auxiliary Roof
Mounted Lamp . . . . . . . . . . . . . . . 6-6
Cargo . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Daytime Running (DRL) . . . . . . . 6-3
Dome . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8 Lamps (cont'd)
Exterior Controls . . . . . . . . . . . . . . . 6-1
Exterior Lamps Off
Reminder . . . . . . . . . . . . . . . . . . . . 6-2
License Plate . . . . . . . . . . . . . . . 10-42
Malfunction Indicator . . . . . . . . . 5-22
Messages . . . . . . . . . . . . . . . . . . . . 5-43
Pick-up Box Identification and Fender Marker . . . . . . . . 10-40
Reading . . . . . . . . . . . . . . . . . . . . . . . 6-8
Taillamps . . . . . . . . . . . . . . . . . . . 10-40
Lap Belt . . . . . . . . . . . . . . . . . . . . . . . 3-19
Lap-Shoulder Belt . . . . . . . . . . . . . 3-14
LATCH System Replacing Parts after aCrash . . . . . . . . . . . . . . . . . . . . . . . 3-55
LATCH, Lower Anchors and Tethers for Children . . . . . . . . . . 3-47
Lighter, Cigarette . . . . . . . . . . . . . . 5-10
Lighting Entry . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9
Illumination Control . . . . . . . . . . . . 6-7