2012 GMC SIERRA 1500 brakes

Black plate (55,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Vehicle Care 10-55
Light Truck (LT‐Metric) Tire
(A) Light Truck (LT‐Metric)
Tire
:The United States version
of a metric tire sizing system.
The letters LT as the first two
characters in the tire size mean
a light truck tire engineered to
standards set by the U.S. Tire
and Rim Association.
(B) Tire Width
:The three‐digit
number indicates the tire section
width in millimeters from
sidewall to sidewall.
(C) Aspect Ratio
:A two‐digit
number that indicates the tire
height‐to‐width measurements.
For example, if the tire size
aspect ratio is 75, as shown
in item C of the light truck (LT‐Metric) tire illustration, it
would mean that the tire's
sidewall is 75 percent as high
as it is wide.
(D) Construction Code
:A
letter code is used to indicate
the type of ply construction in
the tire. The letter R means
radial ply construction; the
letter D means diagonal or
bias ply construction; and the
letter B means belted‐bias ply
construction.
(E) Rim Diameter
:Diameter of
the wheel in inches.
(F) Load Range
:Load Range.
(G) Service Description
:The
service description indicates the
load index and speed rating of a
tire. If two numbers are given as
in the example, 120/116, then
this represents the load index for
single versus dual wheel usage (single/dual). The speed rating is
the maximum speed a tire is
certified to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount
of air inside the tire pressing
outward on each square inch
of the tire. Air pressure is
expressed in kPa (kilopascal)
or psi (pounds per square inch).
Accessory Weight
:The
combined weight of optional
accessories. Some examples
of optional accessories are
automatic transmission, power
steering, power brakes, power
windows, power seats, and air
conditioning.
Aspect Ratio
:The relationship
of a tire's height to its width.

Black plate (70,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-70 Vehicle Care
Vehicles that have a tire pressure
monitoring system could give an
inaccurate low‐pressure warning
if non‐TPC Spec rated tires are
installed. SeeTire Pressure Monitor
System on page 10‑60.
The Tire and Loading Information
label indicates the original
equipment tires on the vehicle. See
Vehicle Load Limits on page 9‑16
for the label location and more
information about the Tire and
Loading Information label.
Different Size Tires and
Wheels
If wheels or tires are installed that
are a different size than the original
equipment wheels and tires, vehicle
performance, including its braking,
ride and handling characteristics,
stability, and resistance to rollover
may be affected. If the vehicle has
electronic systems such as antilock
brakes, rollover airbags, traction control, and electronic stability
control, the performance of these
systems can also be affected.
{WARNING
If different sized wheels are used,
there may not be an acceptable
level of performance and safety
if tires not recommended for
those wheels are selected. This
increases the chance of a crash
and serious injury. Only use GM
specific wheel and tire systems
developed for the vehicle, and
have them properly installed by a
GM certified technician.
See Buying New Tires on
page 10‑68 andAccessories and
Modifications on page 10‑3.
Uniform Tire Quality
Grading
Quality grades can be found
where applicable on the tire
sidewall between tread shoulder
and maximum section width. For
example:
Treadwear 200 Traction AA
Temperature A
The following information relates
to the system developed by the
United States National Highway
Traffic Safety Administration
(NHTSA), which grades tires
by treadwear, traction, and
temperature performance. This
applies only to vehicles sold in
the United States. The grades
are molded on the sidewalls of
most passenger car tires. The
Uniform Tire Quality Grading
(UTQG) system does not apply
to deep tread, winter tires,
compact spare tires, tires with

Black plate (74,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-74 Vehicle Care
Tire Chains
{WARNING
If the vehicle has dual wheels
or P265/65R18, P275/55R20,
LT265/70R17, LT265/70R18,
LT265/60R20, P285/50R20,
P285/45R22 or 285/45R22 size
tires, do not use tire chains. They
can damage the vehicle because
there is not enough clearance.
Tire chains used on a vehicle
without the proper amount of
clearance can cause damage to
the brakes, suspension, or other
vehicle parts. The area damaged
by the tire chains could cause you
to lose control of the vehicle and
you or others may be injured in a
crash.(Continued)
WARNING (Continued)
Use another type of traction
device only if its manufacturer
recommends it for use on the
vehicle and tire size combination
and road conditions. Follow that
manufacturer's instructions. To
help avoid damage to the vehicle,
drive slowly, readjust, or remove
the device if it is contacting the
vehicle, and do not spin the
vehicle's wheels.
If you do find traction devices that
will fit, install them on the rear
tires. Notice:
If the vehicle does not
have dual wheels and has a tire
size other than P265/65R18,
P275/55R20, LT265/70R17,
LT265/70R18, LT265/60R20,
P285/50R20, P285/45R22, or
285/45R22, use tire chains only
where legal and only when you
must. Use chains that are the
proper size for the tires. Install
them on the tires of the rear axle.
Do not use chains on the tires of
the front axle. Tighten them as
tightly as possible with the
ends securely fastened. Drive
slowly and follow the chain
manufacturer's instructions.
If you can hear the chains
contacting the vehicle, stop and
retighten them. If the contact
continues, slow down until it
stops. Driving too fast or
spinning the wheels with chains
on will damage the vehicle.

Black plate (1,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Service and Maintenance 11-1
Service and
Maintenance
General Information
General Information . . . . . . . . . . 11-1
Maintenance Schedule
Maintenance Schedule . . . . . . . 11-3
Special Application Services
Special ApplicationServices . . . . . . . . . . . . . . . . . . . . 11-8
Additional Maintenance
and Care
Additional Maintenanceand Care . . . . . . . . . . . . . . . . . . . 11-9
Recommended Fluids,
Lubricants, and Parts
Recommended Fluids andLubricants . . . . . . . . . . . . . . . . . 11-12
Maintenance Replacement Parts . . . . . . . . . . . . . . . . . . . . . . 11-15
Maintenance Records
Maintenance Records . . . . . . 11-16
General Information
This maintenance section applies to
vehicles with a gasoline engine. For
diesel engine vehicles, see the
maintenance schedule section in
the Duramax Diesel Supplement.
Your vehicle is an important
investment. This section describes
the required maintenance for the
vehicle. Follow this schedule to
help protect against major repair
expenses resulting from neglect or
inadequate maintenance. It may
also help to maintain the value of
the vehicle if it is sold. It is the
responsibility of the owner to have
all required maintenance performed.
Your dealer has trained
technicians who can perform
required maintenance using
genuine replacement parts.
They have up‐to‐date tools and
equipment for fast and accurate
diagnostics. Many dealers have
extended evening and Saturday hours, courtesy transportation, and
online scheduling to assist with
service needs.
Your dealer recognizes the
importance of providing
competitively priced maintenance
and repair services. With trained
technicians, the dealer is the place
for routine maintenance such as oil
changes and tire rotations and
additional maintenance items like
tires, brakes, batteries, and wiper
blades.
Notice:
Damage caused by
improper maintenance can lead to
costly repairs and may not be
covered by the vehicle warranty.
Maintenance intervals, checks,
inspections, recommended fluids,
and lubricants are important to
keep the vehicle in good working
condition.
The Tire Rotation and Required
Services are the responsibility of the
vehicle owner. It is recommended to
have your dealer perform these
services every 12 000 km/7,500 mi.

Black plate (9,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Service and Maintenance 11-9
Additional
Maintenance and Care
Your vehicle is an important
investment and caring for it
properly may help to avoid
future costly repairs. To maintain
vehicle performance, additional
maintenance services may be
required. It is recommended
that your dealer perform these
services—their trained dealer
technicians know your vehicle
best. Your dealer can also
perform a thorough assessment
with a multi‐point inspection to
recommend when your vehicle may
need attention. The following list is
intended to explain the services
and conditions to look for that may
indicate services are required. Battery
The battery supplies power to
start the engine and operate any
additional electrical accessories.
.To avoid break‐down or failure
to start the vehicle, maintain a
battery with full cranking power.
.Trained dealer technicians have
the diagnostic equipment to test
the battery and ensure that the
connections and cables are
corrosion‐free.
Belts
.Belts may need replacing if
they squeak or show signs of
cracking or splitting.
.Trained dealer technicians
can inspect the belts and
recommend replacement when
necessary. Brakes
Brakes stop the vehicle and are
crucial to safe driving.
.Signs of brake wear may include
chirping, grinding, or squealing
noises, or difficulty stopping.
.Trained dealer technicians have
access to tools and equipment
to inspect the brakes and
recommend quality parts
engineered for the vehicle.
Fluids
Proper fluid levels and approved
fluids protect the vehicle’s
systems and components. See
Recommended Fluids and
Lubricants on page 11‑12 for GM
approved fluids.
.Engine oil and windshield
washer fluid levels should be
checked at every fuel fill.
.Instrument cluster lights may
come on to indicate that fluids
may be low and need to be
filled.

Black plate (16,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
13-16 Customer Information
.Vehicle make, model, and
model year.
.Vehicle Identification
Number (VIN).
.Insurance company and policy
number.
.General description of the
damage to the other vehicle.
Choose a reputable repair facility
that uses quality replacement parts.
See “Collision Parts” earlier in this
section.
If the airbag has inflated, see What
Will You See after an Airbag
Inflates? on page 3‑27.
Managing the Vehicle Damage
Repair Process
In the event that the vehicle requires
damage repairs, GM recommends
that you take an active role in its
repair. If you have a pre-determined
repair facility of choice, take the
vehicle there, or have it towed there. Specify to the facility that any
required replacement collision parts
be original equipment parts, either
new Genuine GM parts or recycled
original GM parts. Remember,
recycled parts will not be covered by
the GM vehicle warranty.
Insurance pays the bill for the repair,
but you must live with the repair.
Depending on your policy limits,
your insurance company may
initially value the repair using
aftermarket parts. Discuss this with
the repair professional, and insist
on Genuine GM parts. Remember,
if the vehicle is leased, you may be
obligated to have the vehicle
repaired with Genuine GM parts,
even if your insurance coverage
does not pay the full cost.
If another party's insurance
company is paying for the repairs,
you are not obligated to accept a
repair valuation based on that
insurance company's collision
policy repair limits, as you have no
contractual limits with that company.In such cases, you can have control
of the repair and parts choices as
long as the cost stays within
reasonable limits.
Service Publications
Ordering Information
Service Manuals
Service Manuals have the diagnosis
and repair information on the
engines, transmission, axle,
suspension, brakes, electrical,
steering, body, etc.
Service Bulletins
Service Bulletins give additional
technical service information
needed to knowledgeably service
General Motors cars and trucks.
Each bulletin contains instructions
to assist in the diagnosis and
service of the vehicle.

Black plate (5,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
OnStar 14-5
Diagnostics
OnStar Vehicle Diagnostics will
perform a vehicle check every
month. It will check the engine,
transmission, antilock brakes, and
major vehicle systems. It also
checks the tire pressures, if the
vehicle is equipped with the Tire
Pressure Monitoring System. If a
diagnostics check is needed
between e-mails, push
Q, and an
Advisor can run a check.
OnStar Additional
Information
Transferring Service
PushQto request account transfer
eligibility information. The Advisor
can assist in canceling or removing
account information. If OnStar
receives information that vehicle
ownership has changed, OnStar
may send a voice message to the
vehicle, requesting updated account
information.
Reactivation for Subsequent
Owners
PushQand follow the prompts to
speak to an Advisor as soon as
possible after acquiring the vehicle.
The Advisor will update vehicle
records and will explain the OnStar
service offers and options available.
How OnStar Service Works
Automatic Crash Response,
Emergency Services, Crisis Assist,
Stolen Vehicle Assistance, Vehicle
Diagnostics, Remote Door Unlock,
Roadside Assistance, Turn-by-Turn
Navigation, and Hands-Free Calling
are available on most vehicles. Not
all OnStar services are available
everywhere or on all vehicles. For
more information, a full description
of OnStar services, system
limitations, and OnStar terms and
conditions, see www.onstar.com
(U.S.) or www.onstar.ca (Canada);
contact OnStar at 1-888-4-ONSTAR
(1‐888‐466‐7827) or TTY
1‐877‐248‐2080; or push
Qto
speak with an Advisor. OnStar
services require a vehicle electrical
system, wireless service, and GPS
satellite technologies to be available
and operating for features to
function properly. These systems
may not operate if the battery is
discharged or disconnected.

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