weight GMC SIERRA 1500 2012 Owner's Guide

Black plate (92,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-92 Driving and Operating
Ask your dealer for trailering
information or advice, or write us at
our Customer Assistance Offices.
SeeCustomer Assistance Offices
(U.S. and Canada) on page 13‑4 or
Customer Assistance Offices
(Mexico) on page 13‑5 for more
information.Weight of the Trailer Tongue
The tongue load (A) of any trailer is
very important because it is also
part of the vehicle weight. The
Gross Vehicle Weight (GVW)
includes the curb weight of the
vehicle, any cargo carried in it, and
the people who will be riding in the
vehicle as well as trailer tongue
weight. Vehicle options, equipment,
passengers and cargo in the vehicle
reduce the amount of tongue weight
the vehicle can carry, which will also
reduce the trailer weight the vehicle
can tow. See “Vehicle Load Limits”
for more information about the
vehicle's maximum load capacity.
Trailer tongue weight (A) should be
10 to 15 percent and fifth-wheel or
gooseneck kingpin weight should be
15 to 25 percent of the loaded trailer
weight up to the maximums for
vehicle series and hitch type.:

Black plate (93,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-93
Vehicle Series Hitch TypeMaximum Tongue
Weight
1500 Weight Carrying 272 kg (600 lbs)
1500 Weight Distributing 499 kg (1,100 lbs)
1500 Fifth-Wheel Gooseneck 680 kg (1,500 lbs)
2500/3500
Standard Box Weight Carrying or
Weight Distributing 680 kg (1,500 lbs)
2500/
3500 Long Box Weight Carrying or
Weight Distributing 907 (2,000 lbs)
2500 Fifth-Wheel Gooseneck 1 361 kg (3,000 lbs)
3500 Single Rear
Wheels Fifth-Wheel Gooseneck 1 814 kg (4,000 lbs)
3500 Dual Rear
Wheels Fifth-Wheel Gooseneck 2 495 kg (5,500 lbs)
*816 kg (41,800 lbs) for vehicles built before October, 2011. Check the
hitch rating label for correct maximum for the vehicle.
Do not exceed the maximum
allowable tongue weight for the
vehicle. Choose the shortest hitch
extension that will position the hitch ball closest to the vehicle. This will
help reduce the effect of trailer
tongue weight on the rear axle.Trailering may be limited by the
vehicle's ability to carry tongue
weight. Tongue or kingpin weight
cannot cause the vehicle to exceed
the GVWR (Gross Vehicle Weight
Rating) or the RGAWR (Rear Gross
Axle Weight Rating). See
“Total
Weight on the Vehicle's Tires” later
in this section for more information.
After loading the trailer, weigh
the trailer and then the tongue,
separately, to see if the weights are
proper. If they are not, adjustments
might be made by moving some
items around in the trailer.
Total Weight on the Vehicle's
Tires
Be sure the vehicle's tires are
inflated to the inflation pressures
found on the Certification Tire
label on the drivers door or
see Vehicle Load Limits on
page 9‑16 for more information.

Black plate (94,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-94 Driving and Operating
Make sure not to exceed the GVWR
limit for the vehicle, or the RGAWR,
with the tow vehicle and trailer fully
loaded for the trip including the
weight of the trailer tongue. If using
a weight-distributing hitch, make
sure not to exceed the RGAWR
before applying the weight
distribution spring bars.
Weight of the Trailering
Combination
It is important that the combination
of the tow vehicle and trailer
does not exceed any of its weight
ratings—GCWR, GVWR, RGAWR,
Trailer Weight Rating, or Tongue
Weight. The only way to be sure it is
not exceeding any of these ratings
is to weigh the tow vehicle and
trailer combination, fully loaded for
the trip, getting individual weights
for each of these items.
Towing Equipment
Hitches
The correct hitch equipment helps
maintain combination control.
Many trailers can be towed with a
weight-carrying hitch which simply
features a coupler latched to the
hitch ball, or a tow eye latched to a
pintle hook. Other trailers may
require a weight-distributing hitch
that uses spring bars to distribute
the trailer tongue weight among
the two vehicle and trailer axles.
Fifth-wheel and gooseneck hitches
may also be used. See “Weight of
the Trailer Tongue” underTrailer
Towing on page 9‑78 for rating limits
with various hitch types.
If a step-bumper hitch will be used,
the bumper could be damaged
in sharp turns. Make sure there
is ample room when turning to avoid
contact between the trailer and the
bumper. Consider using sway controls
with any trailer. Ask a trailering
professional about sway controls or
refer to the trailer manufacturer's
recommendations and instructions.
Weight-Distributing Hitch
Adjustment
A. Body to Ground Distance
B. Front of Vehicle
When using a weight-distributing
hitch, the spring bars should be
adjusted so the distance (A) is the
same after coupling the trailer to the
tow vehicle and adjusting the hitch.

Black plate (95,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-95
Fifth-Wheel and Gooseneck
Trailering
Fifth-wheel and gooseneck trailers
can be used with many pickup
models. These trailers place a
larger percentage of the weight
(kingpin weight) on the tow vehicle
than conventional trailers. Make
sure this weight does not cause the
vehicle to exceed GAWR or GVWR.
Fifth-wheel or gooseneck kingpin
weight should be 15 to 25 percent of
the trailer weight up to the maximum
amount specified in the trailering
chart for the vehicle. See“Weight of
the Trailer” underTrailer Towing on
page 9‑78 for more information.
The hitch should be located in the
pickup bed so that its centerline is
over or slightly in front of the rear
axle. Take care that it is not so far
forward that it will contact the back
of the cab in sharp turns. This is
especially important for short box
pickups. Trailer pin box extensions
and sliding fifth-wheel hitch
assemblies can help this condition. There should be at least six inches
of clearance between the top of the
pickup box and the bottom of the
trailer shelf that extends over
the box.
Make sure the hitch is attached to
the tow vehicle frame rails. Do not
use the pickup box for support.
Safety Chains
Always attach chains between the
vehicle and the trailer. Cross the
safety chains under the tongue
of the trailer to help prevent the
tongue from contacting the road if it
becomes separated from the hitch.
Instructions about safety chains
may be provided by the hitch
manufacturer or by the trailer
manufacturer. If the trailer being
towed weighs up to 2 271 kg
(5,000 lbs) with a factory-installed
step bumper, safety chains may be
attached to the attaching points on
the bumper; otherwise, safety
chains should be attached to holes
on the trailer hitch platform. Always
leave just enough slack so the
combination can turn. Never allow
safety chains to drag on the ground.
Trailer Brakes
A loaded trailer that weighs more
than 900 kg (2,000 lbs) needs to
have its own brake system that is
adequate for the weight of the
trailer. Be sure to read and follow
the instructions for the trailer brakes
so they are installed, adjusted, and
maintained properly.
Do not tap into the vehicle's
hydraulic brake system.
Auxiliary Battery
The auxiliary battery provision can
be used to supply electrical power
to additional equipment that may be
added, such as a slide-in camper.
If the vehicle has this provision, this
relay will be located on the driver
side of the vehicle, next to the
underhood electrical center.

Black plate (98,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-98 Driving and Operating
Electric Brake Control Wiring
Provisions
These wiring provisions are
included with the vehicle as part of
the trailer wiring package. These
provisions are for an electric brake
controller. The instrument panel
contains blunt cut wires behind the
steering column for the trailer brake
controller. The harness contains the
following wires:
.Dark Blue: Brake Signal to
Trailer Connector
.Red/Black: Battery
.Light Blue/White: Brake Switch
.White: Ground
The harness should be installed by
your dealer or a qualified service
center.
If the vehicle is equipped with an
Integrated Trailer Brake Control
(ITBC) System, the blunt cuts exist,
but are not connected further in the harness. If an aftermarket trailer
brake controller is installed, the
ITBC must be disconnected. Do not
power both ITBC and aftermarket
controllers to control the trailer
brakes at the same time.
Tow/Haul Mode
Pressing this button at the end of
the shift lever turns on and off the
Tow/Haul Mode.
This indicator light on the instrument
panel cluster comes on when the
Tow/Haul Mode is on.
Tow/Haul is a feature that assists
when pulling a heavy trailer or a
large or heavy load. See
Tow/Haul
Mode on page 9‑39 for more
information.
Tow/Haul is designed to be most
effective when the vehicle and
trailer combined weight is at least
75 percent of the vehicle's Gross
Combined Weight Rating (GCWR).
See “Weight of the Trailer” under
Trailer Towing on page 9‑78. Tow/
Haul is most useful under the
following driving conditions:
.When pulling a heavy trailer or
a large or heavy load through
rolling terrain.

Black plate (106,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-106 Driving and Operating
Adding a Snow Plow or
Similar Equipment
Before installing a snow plow on the
vehicle, here are some things you
need to know:
Notice:If the vehicle does
not have the snow plow prep
package, adding a plow can
damage the vehicle, and the
repairs would not be covered by
warranty. Unless the vehicle was
built to carry a snow plow, do not
add one to the vehicle. If the
vehicle has the snow plow prep
package, called RPO VYU, then
the payload the vehicle can carry
will be reduced when a snow
plow is installed. The vehicle can
be damaged if either the front or
rear axle ratings or the Gross
Vehicle Weight Rating (GVWR)
are exceeded. Some vehicles are built with a
special snow plow prep package,
called RPO VYU. If the vehicle has
this option, you can add a plow to it,
provided certain weights, such as
the weights on the vehicle's axles
and the Gross Vehicle Weight
Rating (GVWR), are not exceeded.
The plow the vehicle can carry
depends on many things, such as:
.The options the vehicle came
with, and the weight of those
options.
.The weight and number of
passengers intended to be
carried.
.The weight of items added to
the vehicle, like a tool box or
truck cap.
.The total weight of any
additional cargo intended to
be carried.
Say, for example, you have a 318 kg
(700 lb) snow plow. The total weight
of all occupants and cargo inside
the cab should not exceed 135 kg (300 lb). This means that you may
only be able to carry one passenger.
But, even this may be too much if
there is other equipment already
adding to the weight of the vehicle.
Here are some guidelines for safely
carrying a snow plow on the vehicle:
.Make sure the weight on the
front and rear axles does not
exceed the axle rating for each.
.For the front axle, if more cargo
or passengers must be carried,
appropriate counter ballast must
be installed rear of the rear axle.
Counter ballast must be properly
secured so it will not move
during driving.
.Follow the snow plow
manufacturer's
recommendations regarding
rear ballast. Rear ballast may be
required to ensure a proper front
and rear weight distribution ratio,
even though the actual weight at
the front axle may be less than
the front axle rating.

Black plate (107,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-107
.The snow plow manufacturer
or installer can assist you in
determining the amount of rear
ballast required, to help make
sure the snowplow/vehicle
combination does not exceed
the GVW rating, the front and
rear axle ratings, and the front
and rear weight distribution ratio.
.The total vehicle must not
exceed the GVW rating.
Front axle reserve capacity is the
difference between the Gross Axle
Weight Rating (GAWR) and the front
axle weight of the vehicle with full
fuel and passengers. Basically, it is
the amount of weight that can be
added to the front axle before
reaching the front GAWR.
The front axle reserve capacity
for the vehicle can be found
in the lower right corner of the
Certification/Tire label, as shown.
United States
Canada In order to calculate the amount of
weight any front accessory, such as
a snow plow, is adding to the front
axle, use the following formula:
(W x (A + W.B.)) /W.B.= Weight
the accessory is adding to the
front axle.
Where:
W = Weight of added accessory
A = Distance that the accessory
is in front of the front axle
W.B. = Vehicle Wheelbase

Black plate (108,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-108 Driving and Operating
For example, adding a 318 kg
(700 lb) snow plow actually adds
more than 318 kg (700 lb) to the
front axle. Using the formula, if the
snow plow is 122 cm (4 ft) in front of
the front axle and the wheel base is
305 cm (10 ft), then:W = 318 kg (700 lb)
A = 122 cm (4 ft)
W.B. = 305 cm (10 ft)
(W x (A + W.B.))/W.B. =
(318 x (122 + 305))/305 = 445 kg
(980 lbs)
So, if the front axle reserve capacity
is more than 445 kg (980 lbs), the
snow plow could be added without
exceeding the front GAWR.
Heavier equipment can be added
on the front of the vehicle if it is
compensated for by carrying fewer
passengers, less cargo, or by
positioning cargo toward the rear.
This has the effect of reducing the
load on the front. However, the front
GAWR, rear GAWR, and the Gross
Vehicle Weight Rating (GVWR) must
never be exceeded.{WARNING
On some vehicles that have
certain front mounted equipment,
such as a snow plow, it may be
possible to load the front axle to
the front gross axle weight rating
(GAWR) but not have enough
weight on the rear axle to have
proper braking performance. If
the brakes cannot work properly,
you could have a crash. To help
the brakes work properly when
a snow plow is installed,
always follow the snow plow
manufacturer or installer's
recommendation for rear ballast
to ensure a proper front and rear
weight distribution ratio, even
though the actual front weight
may be less than the front
GAWR, and the total vehicle
weight is less than the gross
vehicle weight rating (GVWR).
Maintaining a proper front and (Continued)
WARNING (Continued)
rear weight distribution ratio is
necessary to provide proper
braking performance.
Total vehicle reserve capacity is the
difference between the GVWR and
the weight of the truck with full fuel
and passengers. It is the amount
of weight that can be added to the
vehicle before reaching the GVWR.
Keep in mind that reserve capacity
numbers are intended as a guide
when selecting the amount of
equipment or cargo the truck can
carry. If unsure of the vehicle's front,
rear, or total weight, go to a weigh
station and weigh the vehicle. Your
dealer can also help with this.
The total vehicle reserve capacity
for the vehicle can be found
in the lower right corner of the
Certification/Tire label as shown
previously.

Black plate (34,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-34 Vehicle Care
.For all 6.6 L Duramax Diesel
2500HD Series applications and
all 3500 Series applications, the
proper level is from 17 mm to
21 mm (0.6 in to 0.8 in) below
the bottom of the fill plug hole,
located on the rear axle. Add
only enough fluid to reach the
proper level.
What to Use
Refer toRecommended Fluids
and Lubricants on page 11‑12 to
determine what kind of lubricant
to use.
Noise Control System
The following information relates
to compliance with federal noise
emission standards for vehicles with
a Gross Vehicle Weight Rating
(GVWR) of more than 4 536 kg
(10,000 lbs). The noise control
system warranty is given in your
warranty booklet.
These standards apply only to
vehicles sold in the United States. Federal law prohibits the following
acts or the causing thereof:
1. The removal or rendering
inoperative by any person,
other than for purposes of
maintenance, repair or
replacement, of any device or
element of design incorporated
into any new vehicle for the
purpose of noise control, prior to
its sale or delivery to the ultimate
purchaser or while it is in use; or
2. The use of the vehicle after such device or element of design has
been removed or rendered
inoperative by any person.
Among those acts presumed to
constitute tampering are the acts
listed below.
Insulation:
Removal of the noise shields or any
underhood insulation. Engine:
Removal or rendering engine speed
governor, if the vehicle has one,
inoperative so as to allow engine
speed to exceed manufacturer
specifications.
Fan and Drive:
.Removal of fan clutch, if the
vehicle has one, or rendering
clutch inoperative.
.Removal of the fan shroud, if the
vehicle has one.
Air Intake:
.Removal of the air cleaner
silencer.
.Modification of the air cleaner.
Exhaust:
.Removal of the muffler and/or
resonator.
.Removal of the exhaust pipes
and exhaust pipe clamps.

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.