2012 GMC SIERRA 1500 height

Black plate (39,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Seats and Restraints 3-39
If an airbag inflates, you will need to
replace airbag system parts. See
your dealer for service.
If the airbag readiness light stays on
after the vehicle is started or comes
on when you are driving, the airbag
system may not work properly. Have
the vehicle serviced right away.
SeeAirbag Readiness Light on
page 5‑18.Child Restraints
Older Children
Older children who have outgrown
booster seats should wear the
vehicle safety belts. The manufacturer's instructions that
come with the booster seat state the
weight and height limitations for that
booster. Use a booster seat with a
lap-shoulder belt until the child
passes the fit test below:
.Sit all the way back on the seat.
Do the knees bend at the seat
edge? If yes, continue. If no,
return to the booster seat.
.Buckle the lap-shoulder belt.
Does the shoulder belt rest on
the shoulder? If yes, continue.
If no, try using the rear safety
belt comfort guide. See
“Rear
Safety Belt Comfort Guides”
under Lap-Shoulder Belt on
page 3‑14 for more information.
If the shoulder belt still does not
rest on the shoulder, then return
to the booster seat.

Black plate (43,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Seats and Restraints 3-43
weight, height, and age but also
whether or not the restraint will
be compatible with the motor
vehicle in which it will be used.
For most basic types of child
restraints, there are many
different models available. When
purchasing a child restraint, be
sure it is designed to be used
in a motor vehicle. If it is, the
restraint will have a label saying
that it meets federal motor
vehicle safety standards.
The restraint manufacturer's
instructions that come with the
restraint state the weight and
height limitations for a particular
child restraint. In addition, there
are many kinds of restraints
available for children with
special needs.{WARNING
To reduce the risk of neck and
head injury during a crash,
infants need complete support.
In a crash, if an infant is in a
rear-facing child restraint, the
crash forces can be distributed
across the strongest part of an
infant's body, the back and
shoulders. Infants should always
be secured in rear-facing child
restraints.
{WARNING
A young child's hip bones are still
so small that the vehicle's regular
safety belt may not remain low
on the hip bones, as it should.
Instead, it may settle up around
the child's abdomen. In a crash,
the belt would apply force on a
body area that is unprotected by
any bony structure. This alone
could cause serious or fatal
injuries. To reduce the risk of
serious or fatal injuries during a
crash, young children should
always be secured in appropriate
child restraints.

Black plate (21,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-21
{WARNING
Things you put inside the
vehicle can strike and injure
people in a sudden stop or
turn, or in a crash.
.Put things in the cargo
area of the vehicle. Try to
spread the weight evenly.
.Never stack heavier
things, like suitcases,
inside the vehicle so that
some of them are above
the tops of the seats.
.Do not leave an
unsecured child restraint
in the vehicle.
.When you carry something
inside the vehicle, secure
it whenever you can.
.Do not leave a seat folded
down unless you need to. There is also important loading
information for off-road driving
in this manual. See
“Loading
Your Vehicle for Off-Road
Driving“under Off-Road Driving
on page 9‑6.
Two-Tiered Loading
Depending on the model of your
pick‐up, an upper load platform
can be created by positioning
three or four 5 cm (2 inches) by
15 cm (6 inches) wooden planks
across the width of the pickup
box. The planks must be
inserted in the pickup box
depressions. When using this upper load
platform, be sure the load is
securely tied down to prevent it
from shifting. The load's center
of gravity should be positioned
in a zone over the rear axle.
The zone is located in the area
between the front of each wheel
well and the rear of each wheel
well. The center of gravity height
must not extend above the top
of the pickup box flareboard.
Any load that extends beyond
the vehicle's taillamp area must
be properly marked according to
local laws and regulations.
Remember not to exceed
the Gross Axle Weight
Rating (GAWR) of the front or
rear axle.

Black plate (27,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Vehicle Care 10-27
Brakes
This vehicle has front disc brakes
and could have rear drum brakes or
rear disc brakes.
Disc brake pads have built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn and new pads are needed.
The sound can come and go or be
heard all the time the vehicle is
moving, except when applying the
brake pedal firmly.
{WARNING
The brake wear warning sound
means that soon the brakes will
not work well. That could lead to
a crash. When the brake wear
warning sound is heard, have the
vehicle serviced.
Notice: Continuing to drive with
worn-out brake pads could result
in costly brake repair. Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the brakes.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and
evenly tighten wheel nuts in the
proper sequence to torque
specifications in
Capacities and
Specifications on page 12‑2.
If the vehicle has rear drum brakes,
they do not have wear indicators,
but if a rear brake rubbing noise is
heard, have the rear brake linings
inspected immediately. Rear brake
drums should be removed and
inspected each time the tires are
removed for rotation or changing.
Drum brakes have an inspection
hole to inspect lining wear during
scheduled maintenance. When the
front brake pads are replaced, have
the rear brakes inspected, too. Brake linings should always be
replaced as complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal
does not return to normal height,
or if there is a rapid increase in
pedal travel. This could be a sign
that brake service might be
required.
Brake Adjustment
Every time the brakes are applied,
with or without the vehicle moving,
the brakes adjust for wear.
Replacing Brake System Parts
The braking system on a vehicle is
complex. Its many parts have to be
of top quality and work well together
if the vehicle is to have really good
braking. The vehicle was designed
and tested with top-quality brake
parts. When parts of the braking
system are replaced, be sure to get
new, approved replacement parts.

Black plate (38,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-38 Vehicle Care
Headlamp aiming is done with the
vehicle's low-beam headlamps.
The high-beam headlamps will be
correctly aimed if the low-beam
headlamps are aimed properly.
To adjust the vertical aim:
1. Open the hood. SeeHood on
page 10‑5
2. Locate the aim dot on the lens of the low‐beam headlamp.
3. Record the distance from the ground to the aim dot on the
low‐beam headlamp.
4. At a wall, measure from the
ground upward (A) to the
recorded distance from
Step 3 and mark it.
5. Draw or tape a horizontal line (B) on the wall the width of the
vehicle at the height of the mark
in Step 4.
Notice: Do not cover a headlamp
to improve beam cut-off when
aiming. Covering a headlamp may
cause excessive heat build-up
which may cause damage to the
headlamp. 6. Turn on the low-beam
headlamps and place a piece
of cardboard or equivalent in
front of the headlamp not being
adjusted. This allows only the
beam of light from the headlamp
being adjusted to be seen on the
flat surface.
7. Locate the vertical headlamp
aiming screws, which are under
the hood near each headlamp
assembly.
The adjustment screw can be
turned with an E8 Torx
®socket.

Black plate (52,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-52 Vehicle Care
Tire Sidewall Labeling
Useful information about a tire
is molded into the sidewall.
The examples show a typical
passenger and light truck tire
sidewall.
Passenger (P‐Metric) Tire
(A) Tire Size:The tire size
code is a combination of letters
and numbers used to define a
particular tire's width, height,
aspect ratio, construction type, and service description. See
the
“Tire Size” illustration later
in this section for more detail.
(B) TPC Spec (Tire
Performance Criteria
Specification)
:Original
equipment tires designed to
GM's specific tire performance
criteria have a TPC specification
code molded onto the sidewall.
GM's TPC specifications meet
or exceed all federal safety
guidelines.
(C) DOT (Department of
Transportation)
:The
Department of Transportation
(DOT) code indicates that
the tire is in compliance
with the U.S. Department of
Transportation Motor Vehicle
Safety Standards. (D) Tire Identification Number
(TIN)
:The letters and numbers
following the DOT code are
the Tire Identification Number
(TIN). The TIN shows the
manufacturer and plant
code, tire size, and date the
tire was manufactured. The TIN
is molded onto both sides of the
tire, although only one side may
have the date of manufacture.
(E) Tire Ply Material
:The type
of cord and number of plies in
the sidewall and under the tread.
(F) Uniform Tire Quality
Grading (UTQG)
:Tire
manufacturers are required
to grade tires based on
three performance factors:
treadwear, traction, and
temperature resistance. For
more information, see Uniform
Tire Quality Grading on
page 10‑70.

Black plate (53,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Vehicle Care 10-53
(G) Maximum Cold Inflation
Load Limit
:Maximum load
that can be carried and the
maximum pressure needed
to support that load. For
information on recommended
tire pressure see Tire Pressure
on page 10‑58 andVehicle Load
Limits on page 9‑16.
Light Truck (LT-Metric) Tire
(A) Tire Size:The tire size
code is a combination of letters
and numbers used to define a
particular tire's width, height, aspect ratio, construction type,
and service description. See the
“Tire Size”
illustration later in this
section for more detail.
(B) TPC Spec (Tire
Performance Criteria
Specification)
:Original
equipment tires designed to
GM's specific tire performance
criteria have a TPC specification
code molded onto the sidewall.
GM's TPC specifications meet
or exceed all federal safety
guidelines.
(C) Dual Tire Maximum Load
:
Maximum load that can be
carried and the maximum
pressure needed to support
that load when used in a dual
configuration. For information on
recommended tire pressure see
Tire Pressure on page 10‑58
and Vehicle Load Limits on
page 9‑16. (D) DOT (Department of
Transportation)
:The
Department of Transportation
(DOT) code indicates that
the tire is in compliance
with the U.S. Department of
Transportation Motor Vehicle
Safety Standards.
(E) Tire Identification Number
(TIN)
:The letters and numbers
following the DOT code are
the Tire Identification Number
(TIN). The TIN shows the
manufacturer and plant code,
tire size, and date the tire was
manufactured. The TIN is
molded onto both sides of the
tire, although only one side may
have the date of manufacture.

Black plate (54,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-54 Vehicle Care
(F) Tire Ply Material:The type
of cord and number of plies in
the sidewall and under the tread.
(G) Single Tire Maximum
Load
:Maximum load that can
be carried and the maximum
pressure needed to support that
load when used as a single. For
information on recommended
tire pressure see Tire Pressure
on page 10‑58 andVehicle Load
Limits on page 9‑16.
Tire Designations
Tire Size
The examples show a typical
passenger vehicle and light
truck tire size.
Passenger (P‐Metric) Tire
(A) Passenger (P‐Metric) Tire:
The United States version of a
metric tire sizing system. The
letter P as the first character in
the tire size means a passenger
vehicle 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 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) Service Description
:These
characters represent the load
index and speed rating of the
tire. The load index represents
the load carrying capacity a tire
is certified to carry. The speed
rating is the maximum speed a
tire is certified to carry a load.