2012 GMC SIERRA 1500 air condition

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 (60,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-60 Vehicle Care
Tire Pressure for
High-Speed Operation
{WARNING
Driving at high speeds, 160 km/h
(100 mph) or higher, puts an
additional strain on tires.
Sustained high-speed driving
causes excessive heat buildup
and can cause sudden tire failure.
You could have a crash and you
or others could be killed. Some
high-speed rated tires require
inflation pressure adjustment for
high-speed operation. When
speed limits and road conditions
are such that a vehicle can be
driven at high speeds, make sure
the tires are rated for high-speed
operation, in excellent condition,
and set to the correct cold tire
inflation pressure for the
vehicle load.Vehicles with P265/70R17 or
P275/55R20 size tires require
inflation pressure adjustment when
driving the vehicle at speeds of
160 km/h (100 mph) or higher.
Set the cold tire inflation pressure
to 20 kPa (3 psi) above the
recommended cold tire pressure
shown on the Tire and Loading
Information label.
Return the tires to the
recommended cold tire inflation
pressure when high-speed driving
has ended. See
Vehicle Load Limits
on page 9‑16 andTire Pressure on
page 10‑58.
Tire Pressure Monitor
System
The Tire Pressure Monitor System
(TPMS) uses radio and sensor
technology to check tire pressure
levels. The TPMS sensors monitor
the air pressure in your tires and
transmit tire pressure readings to a
receiver located in the vehicle. Each tire, including the spare
(if provided), should be checked
monthly when cold and inflated to
the inflation pressure recommended
by the vehicle manufacturer on the
vehicle placard or tire inflation
pressure label. (If your vehicle has
tires of a different size than the size
indicated on the vehicle placard or
tire inflation pressure label, you
should determine the proper tire
inflation pressure for those tires.)
As an added safety feature, your
vehicle has been equipped with a
tire pressure monitoring system
(TPMS) that illuminates a low tire
pressure telltale when one or
more of your tires is significantly
under‐inflated.
Accordingly, when the low tire
pressure telltale illuminates, you
should stop and check your tires
as soon as possible, and inflate
them to the proper pressure.

Black plate (62,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-62 Vehicle Care
Tire Pressure Monitor
Operation
This vehicle may have a Tire
Pressure Monitor System (TPMS).
The TPMS is designed to warn the
driver when a low tire pressure
condition exists. TPMS sensors are
mounted onto each tire and wheel
assembly, excluding the spare tire
and wheel assembly. The TPMS
sensors monitor the air pressure in
the tires and transmit the tire
pressure readings to a receiver
located in the vehicle.
When a low tire pressure condition
is detected, the TPMS illuminates
the low tire pressure warning light
located on the instrument cluster.If the warning light comes on, stop
as soon as possible and inflate the
tires to the recommended pressure
shown on the Tire and Loading
Information label. See
Vehicle Load
Limits on page 9‑16.
A message to check the pressure in
a specific tire displays in the Driver
Information Center (DIC). The low
tire pressure warning light and the
DIC warning message come on at
each ignition cycle until the tires
are inflated to the correct inflation
pressure. If the vehicle has DIC
buttons, tire pressure levels can be
viewed. For additional information
and details about the DIC operation
and displays, see Driver Information
Center (DIC) on page 5‑30 andTire
Messages on page 5‑45.
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then
turn off as the vehicle is driven.
This could be an early indicator that
the air pressure is getting low and
needs to be inflated to the proper
pressure. A Tire and Loading Information
label shows the size of the original
equipment tires and the correct
inflation pressure for the tires when
they are cold. See
Vehicle Load
Limits on page 9‑16, for an example
of the Tire and Loading Information
label and its location. Also see Tire
Pressure on page 10‑58.
The TPMS can warn about a
low tire pressure condition but it
does not replace normal tire
maintenance. See Tire Inspection
on page 10‑65, Tire Rotation on
page 10‑65 andTires on
page 10‑50.
Notice: Tire sealant materials are
not all the same. A non-approved
tire sealant could damage the
TPMS sensors. TPMS sensor
damage caused by using an
incorrect tire sealant is not
covered by the vehicle
warranty. Always use only the
GM-approved tire sealant
available through your dealer or
included in the vehicle.

Black plate (72,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-72 Vehicle Care
The grade C corresponds to a
level of performance which all
passenger car tires must meet
under the Federal Motor Safety
Standard No. 109. Grades B and
A represent higher levels of
performance on the laboratory
test wheel than the minimum
required by law. Warning: The
temperature grade for this tire is
established for a tire that is
properly inflated and not
overloaded. Excessive speed,
underinflation, or excessive
loading, either separately or in
combination, can cause heat
buildup and possible tire failure.Wheel Alignment and Tire
Balance
The tires and wheels were aligned
and balanced at the factory to
provide the longest tire life and best
overall performance. Adjustments to
wheel alignment and tire balancing
will not be necessary on a regular
basis. However, check the
alignment if there is unusual tire
wear or if the vehicle is pulling to
one side or the other. If the vehicle
vibrates when driving on a smooth
road, the tires and wheels might
need to be rebalanced. See your
dealer for proper diagnosis.
Wheel Replacement
Replace any wheel that is bent,
cracked, or badly rusted or
corroded. If wheel nuts keep coming
loose, the wheel, wheel bolts and
wheel nuts should be replaced.
If the wheel leaks air, replace it.
Some aluminum wheels can be
repaired. See your dealer if any of
these conditions exist.
Your dealer will know the kind of
wheel that is needed.
Each new wheel should have the
same load-carrying capacity,
diameter, width, offset and be
mounted the same way as the
one it replaces.
Replace wheels, wheel bolts, wheel
nuts, or Tire Pressure Monitor
System (TPMS) sensors with new
GM original equipment parts.

Black plate (100,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-100 Vehicle Care
Wheels and Trim—Aluminum
or Chrome
Use a soft, clean cloth with mild
soap and water to clean the wheels.
After rinsing thoroughly with clean
water, dry with a soft, clean towel.
A wax may then be applied.
Keep the wheels clean using a soft,
clean cloth with mild soap and
water. Rinse with clean water. After
rinsing thoroughly, dry with a soft,
clean towel. A wax may then be
applied.
Notice: Chrome wheels and other
chrome trim may be damaged if
the vehicle is not washed after
driving on roads that have been
sprayed with magnesium,
calcium, or sodium chloride.
These chlorides are used on
roads for conditions such as
ice and dust. Always wash the
chrome with soap and water after
exposure. Notice:
To avoid surface
damage, do not use strong soaps,
chemicals, abrasive polishes,
cleaners, brushes, or cleaners
that contain acid on aluminum or
chrome-plated wheels. Use only
approved cleaners. Also, never
drive a vehicle with aluminum or
chrome-plated wheels through an
automatic car wash that uses
silicone carbide tire cleaning
brushes. Damage could occur
and the repairs would not be
covered by the vehicle warranty.
Steering, Suspension, and
Chassis Components
Visually inspect front and rear
suspension and steering system for
damaged, loose, or missing parts or
signs of wear. Inspect the power
steering for proper hook-up, binding,
leaks, cracks, chafing, etc. Visually
check constant velocity joints,
rubber boots, and axle seals for
leaks.
Body Component Lubrication
Lubricate all key lock cylinders,
hood hinges, liftgate hinges, and
steel fuel door hinge unless the
components are plastic. Applying
silicone grease on weatherstrips
with a clean cloth will make them
last longer, seal better, and not stick
or squeak.
Underbody Maintenance
Use plain water to flush dirt and
debris from the vehicle's underbody.
Your dealer or an underbody car
washing system can do this. If not
removed, rust and corrosion can
develop.
Sheet Metal Damage
If the vehicle is damaged and
requires sheet metal repair or
replacement, make sure the body
repair shop applies anti-corrosion
material to parts repaired or
replaced to restore corrosion
protection.

Black plate (103,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Vehicle Care 10-103
Instrument Panel, Leather,
Vinyl, & Other Plastic Surfaces
Use a soft microfiber cloth
dampened with water to remove
dust and loose dirt. For a more
thorough cleaning, use a soft
microfiber cloth dampened with a
mild soap solution.
Notice:Soaking or saturating
leather, especially perforated
leather, as well as other interior
surfaces, may cause permanent
damage. Wipe excess moisture
from these surfaces after
cleaning and allow them to dry
naturally. Never use heat, steam,
spot lifters or spot removers. Do
not use cleaners that contain
silicone or wax-based products.
Cleaners containing these
solvents can permanently
change the appearance and
feel of leather or soft trim and
are not recommended. Do not use cleaners that increase
gloss, especially on the instrument
panel. Reflected glare can decrease
visibility through the windshield
under certain conditions.
Notice:
Use of air fresheners may
cause permanent damage to
plastics and painted surfaces.
If an air freshener comes in
contact with any plastic or
painted surface in the vehicle,
blot immediately and clean with a
soft cloth dampened with a mild
soap solution. Damage caused by
air fresheners would not be
covered by the vehicle warranty.
Care of Safety Belts
Keep belts clean and dry.
{WARNING
Do not bleach or dye safety belts.
It may severely weaken them. In
a crash, they might not be able
to provide adequate protection.
Clean safety belts only with mild
soap and lukewarm water.

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 (3,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Service and Maintenance 11-3
Maintenance
Schedule
Owner Checks and Services
At Each Fuel Stop
.Check the engine oil level. See
Engine Oil on page 10‑7.
Once a Month
.Check the tire inflation
pressures. See Tire Pressure on
page 10‑58.
.Inspect the tires for wear. See
Tire Inspection on page 10‑65.
.Check the windshield washer
fluid level. See Washer Fluid on
page 10‑26.
Engine Oil Change
When the CHANGE ENGINE OIL
SOON message displays, have the
engine oil and filter changed within
the next 1 000 km/600 mi. If driven
under the best conditions, the
engine oil life system might not
indicate the need for vehicle service for more than a year. The engine oil
and filter must be changed at least
once a year and the oil life system
must be reset. Your trained dealer
technician can perform this work.
If the engine oil life system is reset
accidentally, service the vehicle
within 5 000 km/3,000 mi since
the last service. Reset the oil life
system when the oil is changed.
See
Engine Oil Life System on
page 10‑10.
Tire Rotation and Required
Services Every 12 000 km/
7,500 mi
Rotate the tires, if recommended
for the vehicle, and perform the
following services. See Tire
Rotation on page 10‑65.
.Check engine oil level and oil
life percentage. If needed,
change engine oil and filter, and
reset oil life system. See Engine
Oil on page 10‑7 andEngine Oil
Life System on page 10‑10.
.Check engine coolant level. See
Engine Coolant on page 10‑19.
.Check windshield washer fluid
level. See Washer Fluid on
page 10‑26.
.Visually inspect windshield
wiper blades for wear, cracking,
or contamination. See Exterior
Care on page 10‑98. Replace
worn or damaged wiper blades.
See Wiper Blade Replacement
on page 10‑36.
.Check tire inflation pressures.
See Tire Pressure on
page 10‑58.
.Inspect tire wear. See Tire
Inspection on page 10‑65.
.Visually check for fluid leaks.
.Inspect engine air cleaner filter.
See Engine Air Cleaner/Filter on
page 10‑17.
.Inspect brake system.