
Black plate (103,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Driving and Operating 9-103
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 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). (Continued)

Black plate (1,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-2
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-3
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-5
Engine Oil . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil Life System . . . . . . 10-9
Automatic Transmission Fluid (4-Speed
Transmission) . . . . . . . . . . . . . 10-10
Automatic Transmission Fluid (6-Speed
Transmission) . . . . . . . . . . . . . 10-12
Engine Air Cleaner/Filter . . . . 10-15
Cooling System . . . . . . . . . . . . 10-16
Engine Coolant . . . . . . . . . . . . . 10-17 Engine Overheating . . . . . . . . 10-20
Overheated Engine
Protection
Operating Mode . . . . . . . . . . . 10-22
Engine Fan . . . . . . . . . . . . . . . . . 10-22
Power Steering Fluid . . . . . . . 10-23
Washer Fluid . . . . . . . . . . . . . . . 10-23
Brakes . . . . . . . . . . . . . . . . . . . . . 10-24
Brake Fluid . . . . . . . . . . . . . . . . . 10-25
Battery . . . . . . . . . . . . . . . . . . . . . 10-27
Four-Wheel Drive . . . . . . . . . . . 10-28
Front Axle . . . . . . . . . . . . . . . . . . 10-29
Rear Axle . . . . . . . . . . . . . . . . . . 10-30
Noise Control System . . . . . . 10-31
Starter Switch Check . . . . . . . 10-32
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-32
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-32
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-33
Wiper Blade Replacement . . . . . . . . . . . . . . 10-33
Glass Replacement . . . . . . . . 10-34
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-34
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-34
Halogen Bulbs . . . . . . . . . . . . . . 10-34
Headlamps, Front Turn Signal, Sidemarker, and
Parking Lamps . . . . . . . . . . . . 10-35
Pick-Up Box Identification and Fender Marker
Lamps . . . . . . . . . . . . . . . . . . . . 10-35
Taillamps (Chassis Cab Models) . . . . . . . . . . . . . . . . . . . 10-36
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-36
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . 10-37
License Plate Lamp . . . . . . . . 10-37
Replacement Bulbs . . . . . . . . . 10-38
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-38
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-39
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-39
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-43

Black plate (2,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
10-2 Vehicle Care
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-46
All-Season Tires . . . . . . . . . . . . 10-47
Winter Tires . . . . . . . . . . . . . . . . 10-48
Summer Tires . . . . . . . . . . . . . . 10-48
Tire Sidewall Labeling . . . . . . 10-48
Tire Designations . . . . . . . . . . . 10-51
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . 10-52
Tire Pressure . . . . . . . . . . . . . . . 10-55
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . 10-56
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-57
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . 10-58
Tire Inspection . . . . . . . . . . . . . . 10-61
Tire Rotation . . . . . . . . . . . . . . . 10-61
Dual Tire Rotation . . . . . . . . . . 10-63
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . 10-64
Buying New Tires . . . . . . . . . . . 10-65
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . 10-66 Uniform Tire Quality
Grading . . . . . . . . . . . . . . . . . . . 10-67
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . 10-68
Wheel Replacement . . . . . . . . 10-69
Tire Chains . . . . . . . . . . . . . . . . . 10-70
If a Tire Goes Flat . . . . . . . . . . 10-70
Tire Changing . . . . . . . . . . . . . . 10-72
Full-Size Spare Tire . . . . . . . . 10-82
Jump Starting
Jump Starting . . . . . . . . . . . . . . 10-82
Towing
Towing the Vehicle . . . . . . . . . 10-87
Recreational Vehicle
Towing . . . . . . . . . . . . . . . . . . . . 10-87
Appearance Care
Exterior Care . . . . . . . . . . . . . . . 10-91
Interior Care . . . . . . . . . . . . . . . . 10-94
Floor Mats . . . . . . . . . . . . . . . . . . 10-97
General Information
For service and parts needs, visit
your dealer. You will receive
genuine GM parts and GM-trained
and supported service people.
Genuine GM parts have one of
these marks:
California Proposition
65 Warning
Most motor vehicles, including this
one, contain and/or emit chemicals
known to the State of California to

Black plate (4,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
10-4 Vehicle Care
If doing some of your own service
work, use the proper service
manual. It tells you much more
about how to service the vehicle
than this manual can. To order the
proper service manual, seeService
Publications Ordering Information
on page 13‑16.
This vehicle has an airbag system.
Before attempting to do your own
service work, see Airbag System
Check on page 3‑37.
Keep a record with all parts receipts
and list the mileage and the date of
any service work performed. See
Maintenance Records on
page 11‑16.
Notice: Even small amounts of
contamination can cause damage
to vehicle systems. Do not allow
contaminants to contact the
fluids, reservoir caps,
or dipsticks.Hood
To open the hood:
1. Pull the handle with this symbol on it. It is inside the vehicle to
the lower left of the steering
wheel.
2. Then go to the front of thevehicle and locate the secondary
hood release, near the center of
the grille.
3. Push the secondary hood release to the right.
4. Lift the hood. Before closing the hood, be sure
all the filler caps are on properly.
Then bring the hood from full
open to within 152 mm (6 in)
from the closed position, pause,
then push the front center of the
hood with a swift, firm motion to
fully close the hood.

Black plate (25,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Vehicle Care 10-25
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 inCapacities 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.
If this is not done, the brakes might
not work properly. For example,
installing disc brake pads that are
wrong for the vehicle, can change
the balance between the front and
rear brakes
—for the worse. The
braking performance expected can
change in many other ways if the
wrong replacement brake parts are
installed.
Brake Fluid
The brake master cylinder reservoir
is filled with DOT 3 brake fluid. See
Engine Compartment Overview on
page 10‑5 for the location of the
reservoir.

Black plate (28,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
10-28 Vehicle Care
Four-Wheel Drive
Transfer Case
When to Check Lubricant
Refer toMaintenance Schedule on
page 11‑3 to determine when to
check the lubricant.
How to Check Lubricant
Electric Shift Transfer Case
A. Fill Plug
B. Drain Plug
Manual Shift Transfer Case
A. Fill Plug
B. Drain PlugActive Transfer Case
A. Fill Plug
B. Drain Plug
To get an accurate reading, the
vehicle should be on a level
surface.
If the level is below the bottom of
the fill plug (A) hole, located on the
transfer case, some lubricant will
need to be added. Add enough
lubricant to raise the level to the
bottom of the fill plug (A) hole. Use
care not to overtighten the plug.

Black plate (44,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
10-44 Vehicle Care
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Fuses Usage
1 Rear Seats
2 Rear Accessory Power Outlet Fuses Usage
3 Steering Wheel Controls Backlight
4 Driver Door Module
5 Dome Lamps, Driver Side Turn Signal Fuses Usage
6 Driver Side Turn Signal, Stoplamp
7 Instrument Panel Back Lighting
8 Passenger Side Turn Signal, Stoplamp
9 Passenger Door Module, Driver Unlock
10 Power Door Lock 2 (Unlock Feature)
11 Power Door Lock 2 (Lock Feature)
12 Stoplamps, Center High‐Mounted
Stoplamp
13 Rear Climate Controls
14 Power Mirror
15 Body Control Module (BCM)
16 Accessory Power Outlets

Black plate (46,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
10-46 Vehicle Care
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 WindowWheels 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
(Continued)
WARNING (Continued)
and a serious crash. See
Vehicle Load Limits on
page 9‑15.
.Underinflated tires pose
the same danger as
overloaded tires. The
resulting crash could
cause serious injury.
Check all tires frequently
to maintain the
recommended pressure.
Tire pressure should be
checked when the tires
are cold.
.Overinflated tires are more
likely to be cut, punctured,
or broken by a sudden
impact— such as when
hitting a pothole. Keep
tires at the recommended
pressure.
(Continued)