2015 GMC SIERRA 1500 towing

Black plate (95,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Driving and Operating 9-95
3. Readjust Trailer Gain anytimevehicle loading, trailer loading,
or road surface conditions
change or if trailer wheel lock-up
is noticed at any time while
towing.
Other ITBC-Related DIC Messages
In addition to displaying TRAILER
GAIN and OUTPUT through the
DIC, trailer connection and ITBC
system status are displayed on
the DIC.
TRAILER CONNECTED: This
message will briefly display when a
trailer with electric brakes is first
connected to the vehicle. This
message will automatically turn off
in about 10 seconds. This message
can be acknowledged before it
automatically turns off. CHECK TRAILER WIRING: This
message will display if:
.The ITBC system first
determines connection to a
trailer with electric brakes and
then the trailer harness becomes
disconnected from the vehicle.
If the disconnect occurs while
the vehicle is stationary, this
message will automatically turn
off in about 30 seconds. This
message will also turn off if it is
acknowledged or if the trailer
harness is reconnected.
If the disconnect occurs while
the vehicle is moving, this
message will continue until the
ignition is turned off. This
message will also turn off if it is
acknowledged or if the trailer
harness is reconnected.
.There is an electrical fault in the
wiring to the trailer brakes. This
message will continue as long
as there is an electrical fault inthe trailer wiring. This message
will also turn off if it is
acknowledged.
To determine if the electrical fault is
on the vehicle side or trailer side of
the trailer wiring harness
connection:
1. Disconnect the trailer wiring harness from the vehicle.
2. Turn the ignition off.
3. Wait 10 seconds, then turn the ignition back to RUN.
4. If the CHECK TRAILER WIRING message reappears, the
electrical fault is on the
vehicle side.
If the CHECK TRAILER WIRING
message only reappears when
connecting the trailer wiring
harness to the vehicle, the
electrical fault is on the
trailer side.
SERVICE TRAILER BRAKE
SYSTEM: This message will display
when there is a problem with the
ITBC system. If this message

Black plate (96,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
9-96 Driving and Operating
continues over multiple ignition
cycles, there is a problem with the
ITBC system. Have the vehicle
serviced.
If either the CHECK TRAILER
WIRING or SERVICE TRAILER
BRAKE SYSTEM message displays
while driving, the ITBC system may
not be fully functional or may not
function at all. When traffic
conditions allow, carefully pull the
vehicle over to the side of the road
and turn the ignition off. Check the
wiring connection to the trailer and
turn the ignition back on. If either of
these messages continues, either
the vehicle or trailer needs service.
A GM dealer may be able to
diagnose and repair problems with
the trailer. However, any diagnosis
and repair of the trailer is not
covered under the vehicle warranty.
Contact your trailer dealer for
assistance with trailer repairs and
trailer warranty information.Trailer Sway
Control (TSC)
Vehicles with StabiliTrak have a
TSC feature. Trailer sway is
unintended side-to-side motion of a
trailer while being towed. If the
vehicle is towing a trailer and the
TSC detects that sway is increasing,
the vehicle brakes are selectively
applied at each wheel, to help
reduce excessive trailer sway. If the
vehicle is equipped with the
Integrated Trailer Brake Control
(ITBC) system, and the trailer has
the electric actuated brake system,
StabiliTrak may also apply the trailer
brakes.
If TSC is enabled, the Traction
Control System (TCS)/StabiliTrak
warning light will flash on the
instrument cluster. Vehicle speed
must be reduced. If trailer sway
continues, StabiliTrak can reduce
engine torque to help slow the
vehicle. SeeTraction Control/
Electronic Stability Control on
page 9-50.
{Warning
Even if the vehicle is equipped
with TSC, trailer sway could result
in loss of control and the vehicle
could crash. If excessive trailer
sway is detected, slow down to a
safe speed. Check the trailer and
vehicle to help correct possible
causes. These could include an
improperly or overloaded trailer,
unrestrained cargo, improper
trailer hitch configuration,
excessive vehicle-trailer speed,
or improperly inflated or incorrect
vehicle or trailer tires. See Towing
Equipment on page 9-87 for
trailer ratings and hitch setup
recommendations.
Adding non-dealer accessories can
affect the vehicle performance. See
Accessories and Modifications on
page 10-3.

Black plate (2,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
10-2 Vehicle Care
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-50
All-Season Tires . . . . . . . . . . . . 10-51
Winter Tires . . . . . . . . . . . . . . . . 10-52
Low-Profile Tires . . . . . . . . . . . 10-52
All-Terrain Tires . . . . . . . . . . . . 10-52
Tire Sidewall Labeling . . . . . . 10-53
Tire Designations . . . . . . . . . . . 10-55
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . 10-57
Tire Pressure . . . . . . . . . . . . . . . 10-59
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . 10-61
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-61
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . 10-62
Tire Inspection . . . . . . . . . . . . . . 10-66
Tire Rotation . . . . . . . . . . . . . . . 10-66
Dual Tire Rotation . . . . . . . . . . 10-68
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . 10-68
Buying New Tires . . . . . . . . . . . 10-69
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . 10-71
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . 10-72
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . 10-73 Wheel Replacement . . . . . . . . 10-73
Tire Chains . . . . . . . . . . . . . . . . . 10-74
If a Tire Goes Flat . . . . . . . . . . 10-75
Tire Changing . . . . . . . . . . . . . . 10-77
Full-Size Spare Tire . . . . . . . . 10-87
Jump Starting
Jump Starting . . . . . . . . . . . . . . 10-88
Towing the Vehicle
Towing the Vehicle . . . . . . . . . 10-93
Recreational Vehicle
Towing . . . . . . . . . . . . . . . . . . . . 10-93
Appearance Care
Exterior Care . . . . . . . . . . . . . . . 10-98
Interior Care . . . . . . . . . . . . . . . 10-103
Floor Mats . . . . . . . . . . . . . . . . 10-106
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 (24,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
10-24 Vehicle Care
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance Program on
page 13-5.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
4.3L V6, 5.3L V8, and 6.2L
V8 Engines
Check to see if the engine cooling
fans are running. If the engine is
overheating, the fans should be
running. If they are not, do not
continue to run the engine and have
the vehicle serviced.
If Steam is Coming from the
Engine Compartment
{Warning
Steam from an overheated engine
can burn you badly, even if you
just open the hood. Stay away(Continued)
Warning (Continued)
from the engine if you see or hear
steam coming from it. Just turn it
off and get everyone away from
the vehicle until it cools down.
Wait until there is no sign of
steam or coolant before you open
the hood.
If you keep driving when the
engine is overheated, the liquids
in it can catch fire. You or others
could be badly burned. Stop the
engine if it overheats, and get out
of the vehicle until the engine
is cool.
If No Steam is Coming from
the Engine Compartment
The ENGINE OVERHEATED STOP
ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message, along with a low coolant
condition, can indicate a serious
problem. If there is an engine overheat
warning, but no steam is seen or
heard, the problem may not be too
serious. Sometimes the engine can
get a little too hot when the vehicle:
.Climbs a long hill on a hot day.
.Stops after high-speed driving.
.Idles for long periods in traffic.
.Tows a trailer; see
Trailer Towing
on page 9-72.
If the ENGINE OVERHEATED
STOP ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message appears with no sign of
steam, try this for a minute or so:
1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest
fan speed. Open the windows as
necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or
N (Neutral) and let the
engine idle.

Black plate (25,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Vehicle Care 10-25
If the temperature overheat gauge is
no longer in the overheat zone or an
overheat warning no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
vehicle distance from the vehicle in
front. If the warning does not come
back on, continue to drive normally
and have the cooling system
checked for proper fill and function.
If the warning continues, pull over,
stop, and park the vehicle
right away.
If there is still no sign of steam and
the vehicle is equipped with an
engine driven cooling fan, push
down the accelerator until the
engine speed is about twice as fast
as normal idle speed for at least
five minutes while the vehicle is
parked. If the warning is still there,
turn off the engine and get everyone
out of the vehicle until it cools down.If there is no sign of steam, idle the
engine for five minutes while
parked. If the warning is still
displayed, turn off the engine until it
cools down.
Overheated Engine
Protection
Operating Mode
If an overheated engine condition
exists and the ENGINE POWER IS
REDUCED message displays, an
overheat protection mode which
alternates firing groups of cylinders
helps to prevent engine damage. In
this mode, a loss in power and
engine performance will be noticed.
This operating mode allows the
vehicle to be driven to a safe place
in an emergency. Driving extended
distances and/or towing a trailer in
the overheat protection mode
should be avoided.
{Caution
After driving in the overheated
engine protection operating
mode, the engine oil will be
severely degraded. Any repairs
performed before the engine is
cool may cause engine damage.
Allow the engine to cool before
attempting any repair. Repair the
cause of coolant loss, change the
oil, and reset the oil life system.
See
Engine Oil on page 10-10.
Engine Fan
If the vehicle has a clutched engine
cooling fan, when the clutch is
engaged, the fan spins faster to
provide more air to cool the engine.
In most everyday driving conditions,
the fan is spinning slower and the
clutch is not fully engaged. This
improves fuel economy and reduces
fan noise. Under heavy vehicle
loading, trailer towing, and/or high
outside temperatures, the fan speed

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 (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 (95,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Vehicle Care 10-95
6. Disconnect the negative batterycable at the battery and secure
the nut and bolt. Cover the
negative battery post with a
non-conductive material to
prevent any contact with the
negative battery terminal.
7. Shift the transmission to P (Park).
{Caution
If the steering column is locked,
vehicle damage may occur.
9. Move the steering wheel to make sure the steering column
is unlocked.
10. Release the parking brake.
11. Keep the ignition key in the towed vehicle in ACC/
ACCESSORY to prevent the
steering column from locking. Disconnecting the Towed Vehicle
Before disconnecting the towed
vehicle:
1. Park on a level surface.
2. Set the parking brake, shift the
transmission to P (Park), and
move the ignition key to OFF.
3. Connect the battery.
4. Apply the brake pedal.
5. Start the engine, then shift the transfer case out of N (Neutral)
to Two-Wheel Drive High. See
Four-Wheel Drive for directions
on shifting out of N (Neutral).
6. Check that the vehicle is in Two-Wheel Drive High by
shifting the transmission to
R (Reverse) and then to D
(Drive). There should be
movement of the vehicle while
shifting.
7. Shift the transmission to P (Park) and turn off the ignition.
8. Disconnect the vehicle from the tow vehicle. 9. Release the parking brake.
10. Reset any lost presets.
The outside temperature
display will default to 32°F but
will reset with normal usage.
Dolly Towing
Front Towing (Front Wheels Off
the Ground) –Two-Wheel-Drive
Vehicles