
Black plate (50,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-50 Vehicle Care
Top View
Harness
Connector Usage
BODY 2 Body Harness
Connector 2
BODY 1 Body Harness
Connector 1
BODY 3 Body Harness
Connector 3
HEADLINER 3 Headliner
Harness
Connector 3 Harness
Connector Usage
HEADLINER 2 Headliner
Harness
Connector 2
HEADLINER 1 Headliner
Harness
Connector 1
SEO/
UPFITTER Special
Equipment Option
Upfitter Harness
Connector
Circuit
Breaker Usage
CB1 Passenger Side
Power Window Circuit
Breaker
CB2 Passenger Seat
Circuit Breaker
CB3 Driver Seat Circuit
Breaker
CB4 Rear Sliding Window
Wheels and Tires
Tires
Every new GM vehicle has
high-quality tires made by a
leading tire manufacturer.
See the warranty manual for
information regarding the tire
warranty and where to get
service. For additional
information refer to the tire
manufacturer.
{WARNING
.Poorly maintained and
improperly used tires are
dangerous.
.Overloading the tires can
cause overheating as a result
of too much flexing. There
could be a blowout and a
serious crash. See Vehicle
Load Limits on page 9‑16.
(Continued)

Black plate (58,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-58 Vehicle Care
Treadwear Indicators:Narrow
bands, sometimes called wear
bars, that show across the tread
of a tire when only 1.6 mm
(1/16 in) of tread remains. See
When It Is Time for New Tires
on page 10‑68.
UTQGS (Uniform Tire Quality
Grading Standards)
:A tire
information system that
provides consumers with
ratings for a tire's traction,
temperature, and treadwear.
Ratings are determined
by tire manufacturers using
government testing procedures.
The ratings are molded into
the sidewall of the tire. See
Uniform Tire Quality Grading on
page 10‑70. Vehicle Capacity Weight
:
The number of designated
seating positions multiplied by
68 kg (150 lbs) plus the rated
cargo load. See
Vehicle Load
Limits on page 9‑16.
Vehicle Maximum Load on the
Tire
:Load on an individual tire
due to curb weight, accessory
weight, occupant weight, and
cargo weight.
Vehicle Placard
:A label
permanently attached to a
vehicle showing the vehicle
capacity weight and the
original equipment tire size
and recommended inflation
pressure. See “Tire and Loading
Information Label” underVehicle
Load Limits on page 9‑16.
Tire Pressure
Tires need the correct amount
of air pressure to operate
effectively.
Notice: Neither tire
underinflation nor
overinflation is good.
Underinflated tires, or tires
that do not have enough air,
can result in:
.Tire overloading and
overheating which could
lead to a blowout.
.Premature or
irregular wear.
.Poor handling.
.Reduced fuel economy.

Black plate (3,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
INDEX i-3
Carbon MonoxideEngine Exhaust . . . . . . . . . . . . . . . 9-33
Tailgate . . . . . . . . . . . . . . . . . . . . . . . 2-10
Winter Driving . . . . . . . . . . . . . . . . 9-13
Cargo Lamp . . . . . . . . . . . . . . . . . . . . 6-8
Cautions, Danger, and Warnings . . . . . . . . . . . . . . . . . . . . . . . . iv
CD Player . . . . . . . . . . . . . . . . . . . . . 7-15
CD/DVD Player . . . . . . . . . . . . . . . . 7-21
Center Console Storage . . . . . . . . 4-2
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 10-42
Center Seat . . . . . . . . . . . . . . . . . . . . 3-4
Chains, Tire . . . . . . . . . . . . . . . . . . 10-74
Charging System Light . . . . . . . . 5-22
Check Engine Light . . . . . . . . . . . . . . . . . . 5-22
IgnitionTransmission Lock . . . . . . . . 10-35 Child Restraints
Infants and Young
Children . . . . . . . . . . . . . . . . . . . . . 3-41
Lower Anchors and Tethers for Children . . . . . . . . . 3-47
Older Children . . . . . . . . . . . . . . . . 3-39
Securing . . . . . . . . . . . . . . . . 3-55, 3-58
Systems . . . . . . . . . . . . . . . . . . . . . . 3-44
Cigarette Lighter . . . . . . . . . . . . . . . 5-10
Circuit Breakers . . . . . . . . . . . . . . 10-44
Cleaning Exterior Care . . . . . . . . . . . . . . . 10-98
Interior Care . . . . . . . . . . . . . . . 10-101
Climate Control Systems . . . 8-1, 8-4 Air Conditioning . . . . . . . . . . 8-1, 8-4
Dual Automatic . . . . . . . . . . . . . . . . 8-5
Heating . . . . . . . . . . . . . . . . . . . 8-1, 8-4
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Cluster, Instrument . . . . . . . . . . . . 5-12
Collision Damage Repair . . . . . 13-14
Compass . . . . . . . . . . . . . . . . . . . . . . . 5-5
Connections, OnStar
®. . . . . . . . . 14-4 Control of a Vehicle . . . . . . . . . . . . . 9-4
Convex Mirrors . . . . . . . . . . . . . . . . 2-14
Coolant
Engine . . . . . . . . . . . . . . . . . . . . . . 10-19
Engine TemperatureGauge . . . . . . . . . . . . . . . . . . . . . . 5-16
Cooling System . . . . . . . . . . . . . . . 10-18
Engine Messages . . . . . . . . . . . . 5-41
Courtesy Transportation Program . . . . . . . . . . . . . . . . . . . . . 13-13
Cruise Control . . . . . . . . . . . . . . . . . 9-58
Light . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30
Cupholders . . . . . . . . . . . . . . . . . . . . . 4-1
Customer Assistance . . . . . . . . . . 13-6 Offices . . . . . . . . . . . . . . . . . . 13-4, 13-5
Text Telephone (TTY)Users . . . . . . . . . . . . . . . . . . . . . . . 13-6
Customer Information Service PublicationsOrdering Information . . . . . . 13-16
Customer Satisfaction
Procedure . . . . . . . . . . . . . . 13-1, 13-3

Black plate (5,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
INDEX i-5
Engine (cont'd)Cooling System Messages . . . 5-41
Drive Belt Routing . . . . . . . . . . . . 12-6
Exhaust . . . . . . . . . . . . . . . . . . . . . . 9-33
Fan . . . . . . . . . . . . . . . . . . . . . . . . . 10-24
Oil Life System . . . . . . . . . . . . . 10-10
Oil Messages . . . . . . . . . . . . . . . . . 5-42
Oil Pressure Gauge . . . . . . . . . . 5-15
Overheated Protection
Operating Mode . . . . . . . . . . . 10-24
Overheating . . . . . . . . . . . . . . . . 10-22
Power Messages . . . . . . . . . . . . . 5-42
Pressure Light . . . . . . . . . . . . . . . . 5-28
Running While Parked . . . . . . . . 9-34
Starting . . . . . . . . . . . . . . . . . . . . . . . 9-27
Entry Lighting . . . . . . . . . . . . . . . . . . . 6-9
Equipment, Towing . . . . . . . . . . . . 9-94
Event Data Recorders . . . . . . . . 13-19
Exit Lighting . . . . . . . . . . . . . . . . . . . . 6-9
Extender, Safety Belt . . . . . . . . . . 3-20
Exterior Lamp Controls . . . . . . . . . 6-1
Exterior Lamps Off Reminder . . . 6-2F
Fan Engine . . . . . . . . . . . . . . . . . . . . . . 10-24
Fast Idle System . . . . . . . . . . . . . . . 9-29
Features Memory . . . . . . . . . . . . . . . . . . . . . . . 1-14
Filter,
Engine Air Cleaner . . . . . . . . . 10-17
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 6-3
Flashers, Hazard Warning . . . . . . 6-5
Flat Tire . . . . . . . . . . . . . . . . . . . . . . 10-75 Changing . . . . . . . . . . . . . . . . . . . 10-76
Floor Mats . . . . . . . . . . . . . . . . . . .10-104
Fluid AutomaticTransmission . . . . . . . 10-11, 10-14
Brakes . . . . . . . . . . . . . . . . . . . . . . 10-28
Four-Wheel Drive Transfer Case . . . . . . . . . . . . . . . 9-40
Power Steering . . . . . . . . . . . . . 10-25
Washer . . . . . . . . . . . . . . . . . . . . . 10-26 Fog Lamps
Bulb Replacement . . . . . . . . . . . . . 6-6
Folding Mirrors . . . . . . . . . . . . . . . . 2-16
Four-Wheel Drive . . . . . . . 9-40, 10-30
Four-Wheel-Drive Light . . . . . . . . 5-26
Front Axle . . . . . . . . . . . . . . . . . . . . 10-31
Front Fog Lamp Light . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29
Front Seats Adjustment . . . . . . . . . . . . . . . . . . . . 3-3
Heated and Ventilated . . . . . . . . . 3-9
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-68 Additives . . . . . . . . . . . . . . . . . . . . . 9-70
E85 (85% Ethanol) . . . . . . . . . . . 9-71
Economy Driving . . . . . . . . . . . . . 1-36
Filling a Portable FuelContainer . . . . . . . . . . . . . . . . . . . 9-73
Filling the Tank . . . . . . . . . . . . . . . 9-72
Foreign Countries . . . . . . . . . . . . 9-69
Gasoline Specifications . . . . . . . 9-69
Gauge . . . . . . . . . . . . . . . . . . . . . . . . 5-14
Low Fuel Warning Light . . . . . . . 5-28

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

Black plate (9,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
INDEX i-9
MirrorsAutomatic Dimming
Rearview . . . . . . . . . . . . . . . . . . . . 2-18
Convex . . . . . . . . . . . . . . . . . . . . . . . 2-14
Folding . . . . . . . . . . . . . . . . . . . . . . . 2-16
Heated . . . . . . . . . . . . . . . . . . . . . . . 2-17
Manual . . . . . . . . . . . . . . . . . . . . . . . 2-14
Manual Rearview . . . . . . . . . . . . . 2-18
Park Tilt . . . . . . . . . . . . . . . . . . . . . . 2-17
Power . . . . . . . . . . . . . . . . . . . . . . . . 2-15
Trailer Tow . . . . . . . . . . . . . . . . . . . . 2-15
Monitor System, Tire Pressure . . . . . . . . . . . . . . . . . . . . 10-60
N
NavigationOnStar®. . . . . . . . . . . . . . . . . . . . . . 14-2
Vehicle Data Recording
and Privacy . . . . . . . . . . . . . . . 13-20
New Vehicle Break-In . . . . . . . . . . 9-25
Noise Control System . . . . . . . . 10-34
O
Object Detection System Messages . . . . . . . . . . . . . . . . . . . . 5-43
Odometer . . . . . . . . . . . . . . . . . . . . . . 5-13 Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13
Off-Road . . . . . . . . . . . . . . . . . . . . . . . 9-6 Driving . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
Recovery . . . . . . . . . . . . . . . . . . . . . . 9-5
Oil Engine . . . . . . . . . . . . . . . . . . . . . . . . 10-7
Engine Oil Life System . . . . . 10-10
Engine Oil PressureGauge . . . . . . . . . . . . . . . . . . . . . . 5-15
Messages . . . . . . . . . . . . . . . . . . . . 5-42
Pressure Light . . . . . . . . . . . . . . . . 5-28
Older Children, Restraints . . . . . 3-39
Online Owner Center . . . . . . . . . . 13-6
OnStar
®
Additional Information . . . . . . . . 14-5
Connections . . . . . . . . . . . . . . . . . . 14-4
Diagnostics . . . . . . . . . . . . . . . . . . . 14-5
Emergency . . . . . . . . . . . . . . . . . . . 14-2 OnStar
®(cont'd)
Navigation . . . . . . . . . . . . . . . . . . . . 14-2
Overview . . . . . . . . . . . . . . . . . . . . . 14-1
Security . . . . . . . . . . . . . . . . . . . . . . 14-2
System, In Brief . . . . . . . . . . . . . . 1-37
Operation, Infotainment System . . . . . . . . . . . . . . . . . . . . . . . . 7-3
Ordering Service Publications . . . . . . . . 13-16
Outlets Power . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
Overheated Engine Protection
Operating Mode . . . . . . . . . . . . . 10-24
Overheating, Engine . . . . . . . . . . 10-22
Overview, OnStar
®. . . . . . . . . . . . 14-1
P
Park Shifting Into . . . . . . . . . . . . . . . . . . . 9-30
Shifting Out of . . . . . . . . . . . . . . . . 9-32
Tilt Mirrors . . . . . . . . . . . . . . . . . . . . 2-17