
Black plate (26,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
10-26 Vehicle Care
increases as the clutch more fully
engages, so an increase in fan
noise may be heard. This is normal
and should not be mistaken as the
transmission slipping or making
extra shifts. It is merely the cooling
system functioning properly. The fan
will slow down when additional
cooling is not required and the
clutch disengages.
This fan noise may also be heard
when starting the engine. It will go
away as the fan clutch partially
disengages.
If the vehicle has electric cooling
fans, the fans may be heard
spinning at low speed during most
everyday driving. The fans may turn
off if no cooling is required. Under
heavy vehicle loading, trailer towing,
high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fan
noise may be heard. This is normal
and indicates that the cooling
system is functioning properly. Thefans will change to low speed when
additional cooling is no longer
required.
The electric engine cooling fans
may run after the engine has been
turned. off. This is normal and no
service is required.
Power Steering Fluid
(1500 Series)
The vehicle has electric power
steering and does not use power
steering fluid.
Power Steering Fluid
(2500/3500 Series)
See
Engine Compartment Overview
on page 10-5 for reservoir location.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless
there is a leak suspected in the
system or an unusual noise is
heard. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired.
Wait for the power steering system
to cool, with the engine off, before
checking the fluid.
How to Check Power Steering
Fluid
To check the power steering fluid:
1. Turn the key off and let the
engine compartment cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a clean rag.
4. Replace the cap and completely tighten it.

Black plate (43,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Vehicle Care 10-43
Micro
J-Case Fuses Usage
1 Trailer Brake
2 Trailer Battery
J-Case Fuses Usage
3 Antilock Brake System Pump
4 Instrument Panel BEC 1
5 Spare
6 4WD Trec
7 Spare
8 Instrument Panel BEC 2
9 Spare
10 Rear Window Defogger
11 Starter
12 Cooling Fan 1

Black plate (44,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
10-44 Vehicle Care
J-CaseFuses Usage
13 Cooling Fan 2
Mini Fuses (2 Pin) Usage
14 Trailer Stop/Turn Lamps, Left
15 Trailer Parking Lamps
16 Trailer Back-up Lamp
17 Trailer Stop/Turn Lamps, Right
Micro Fuses (2 Pin) Usage
18 Fuel Pump
19 Integrated Chassis Control Module
20 Electronic Suspension
Control Module Micro Fuses
(2 Pin) Usage
21 Fuel Pump Power Module
22 Upfitter Switch 1
23 Upfitter 2
24 Front Wiper
25 Antilock Brake System Valves
26 Upfitter SW 2
27 Upfitter SW 3
28 Parking Lamps, Right
29 Parking Lamps, Left
30 Upfitter 3
31 Upfitter SW 4
32 Upfitter 4
33 Back-up Lamps
34 Engine Control Module Ignition Micro Fuses
(2 Pin) Usage
35 Air Conditioning Compressor Clutch
36 Heated Mirrors
37 Upfitter 1
38 Center High-Mounted
Stoplamp
39 Miscellaneous Ignition
40 Transmission Ignition
41 Fuel Pump 2
42 Cooling Fan Clutch
43 Engine
44 Fuel Injectors A, Odd
45 Fuel Injectors B, Even
46 Oxygen Sensor B
47 Throttle Control

Black plate (45,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Vehicle Care 10-45
Micro Fuses(2 Pin) Usage
48 Horn
49 Fog Lamp
50 Oxygen Sensor A
51 Engine Control Module
52 Interior Heater
53 Spare
54 Aeroshutter
55 Front Washer
Micro Fuses (3 Pin) Usage
56 Air Conditioning Compressor/
Battery Regulated
Voltage Control Micro Fuses
(3 Pin) Usage
57 Air Conditioning Compressor
Module/
Battery Pack
58 Transmission Control Module/
Engine Control
Module
59 Headlamps
Micro
Relays Usage
60 Fuel Pump
61 Upfitter 2
62 Upfitter 3
63 Upfitter 4
64 Trailer Parking Lamps
65 Run/Crank
66 Upfitter 1 Micro
Relays Usage
67 Fuel Pump 2
68 Air Conditioning Control
69 Starter
Mini Relays Usage 70 Rear Window Defogger
71 Engine Control Module
Solid State Relay Usage
72 Cooling Fan Clutch

Black plate (54,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
10-54 Vehicle Care
(6) 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 10-72.
(7) 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 10-59 andVehicle Load
Limits on page 9-15.
(8) Temporary Use Only
:Only
use a temporary spare tire until
the road tire is repaired and
replaced. This spare tire should
not be driven on over 112 km/h
(70 mph), or 88 km/h (55 mph)
when pulling a trailer, with the proper inflation pressure. See
Full-Size Spare Tire on
page 10-87.
Light Truck (LT-Metric) Tire
(1) 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. (2) 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.
(3) 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 10-59
and Vehicle Load Limits on
page 9-15.
(4) DOT (Department of
Transportation)
:The
Department of Transportation
(DOT) code indicates that the
tire is in compliance with the

Black plate (88,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
10-88 Vehicle Care
If equipped with a temporary use
full-size spare tire, it is indicated on
the tire sidewall. SeeTire Sidewall
Labeling on page 10-53. This spare
tire should not be driven on over
112 km/h (70 mph), or 88 km/h
(55 mph) when pulling a trailer, at
the proper inflation pressure.
Repair and replace the road tire as
soon as it is convenient, and stow
the spare tire for future use.
{Caution
If the vehicle has four-wheel drive
and a different size spare tire is
installed, do not drive in
four-wheel drive until the flat tire
is repaired and/or replaced. The
vehicle could be damaged and
the repairs would not be covered
by the warranty. Never use
four-wheel drive when a different
size spare tire is installed on the
vehicle. The vehicle may have a different
size spare tire than the road tires
originally installed on the vehicle.
This spare tire was developed for
use on this vehicle, so it is all right
to drive on it. If the vehicle has
four-wheel drive and a different size
spare tire is installed, drive only in
two-wheel drive.
After installing the spare tire on the
vehicle, stop as soon as possible
and check that the spare tire is
correctly inflated.
Have the damaged or flat road tire
repaired or replaced and installed
back onto the vehicle as soon as
possible so the spare tire will be
available in case it is needed again.
Do not mix tires and wheels of
different sizes, because they will not
fit. Keep your spare tire and its
wheel together. If the vehicle has a
spare tire that does not match the
original road tires and wheels in size
and type, do not include the spare in
the tire rotation.
Jump Starting
For more information about the
vehicle battery, see
Battery on
page 10-30.
If the vehicle's battery (or batteries)
has run down, you may want to use
another vehicle and some jumper
cables to start your vehicle. Be sure
to use the following steps to do it
safely.
{Warning
Batteries can hurt you. They can
be dangerous because:
.They contain acid that can
burn you.
.They contain gas that can
explode or ignite.
.They contain enough
electricity to burn you.
If you do not follow these steps
exactly, some or all of these
things can hurt you.

Black plate (93,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Vehicle Care 10-93
Towing the Vehicle
{Caution
Incorrectly towing a disabled
vehicle may cause damage. The
damage would not be covered by
the vehicle warranty. Do not lash
or hook to the chassis
components—including the front
and rear subframes, suspension
control arms, and links —during
towing and recovery of a disabled
vehicle, or when securing the
vehicle. Use the proper nylon
strap harnesses around the tires
to secure the vehicle.
Have the vehicle towed on a flatbed
car carrier. A wheel lift tow truck
could damage the vehicle.
Consult your dealer or a
professional towing service if the
disabled vehicle must be towed. To tow the vehicle behind another
vehicle for recreational purposes,
such as behind a motor home, see
“Recreational Vehicle Towing”
following.
Recreational Vehicle
Towing
Recreational vehicle towing means
towing the vehicle behind another
vehicle, such as a motor home. The
two most common types of
recreational vehicle towing are
dinghy and dolly towing. Dinghy
towing is towing the vehicle with all
four wheels on the ground. Dolly
towing is towing the vehicle with two
wheels on the ground and two
wheels on a dolly.
Follow the tow vehicle
manufacturer
’s instructions. See
your dealer or trailering professional
for additional advice and equipment
recommendations.
{Caution
Use of a shield mounted in front
of the vehicle grille could restrict
airflow and cause damage to the
transmission. The repairs would
not be covered by the vehicle
warranty. If using a shield, only
use one that attaches to the
towing vehicle.
Dinghy Towing
Two-Wheel-Drive Vehicles

Black plate (2,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
11-2 Service and Maintenance
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.
Proper vehicle maintenance helps to
keep the vehicle in good working
condition, improves fuel economy,
and reduces vehicle emissions.
Because of the way people use
vehicles, maintenance needs vary.
There may need to be more
frequent checks and services.
Normal Service
All maintenance services, including
those listed under Additional
Required Services, are for
vehicles that:
.Carry passengers and cargo
within recommended limits on
the Tire and Loading Information
label. SeeVehicle Load Limits
on page 9-15.
.Are driven on reasonable road
surfaces within legal driving
limits.
.Use the recommended fuel. See
Fuel on page 9-64.
Severe Service
In addition to the normal service
schedule, some vehicles require
service more often. Severe service
is for vehicles that are:
.Mainly driven in heavy city traffic
in hot weather.
.Mainly driven in hilly or
mountainous terrain.
.Frequently towing a trailer.
.Used for high-speed or
competitive driving.
.Used for taxi, police, or delivery
service.
{Warning
Performing maintenance work can
be dangerous and can cause
serious injury. Perform
maintenance work only if the
required information, proper tools, (Continued)
Warning (Continued)
and equipment are available.
If they are not, see your dealer to
have a trained technician do the
work. SeeDoing Your Own
Service Work on page 10-3.