Black plate (59,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
Driving and Operating 9-59
nozzle. Clean fuel from painted
surfaces as soon as possible. See
Exterior Care on page 10-86.
When replacing the fuel cap, insert
the tether in its hole before
tightening the cap. Turn the fuel cap
clockwise until it clicks. It will require
more effort to turn the fuel cap on
the last turn as you tighten it. Make
sure the cap is fully installed. The
diagnostic system can determine if
the fuel cap has been left off or
improperly installed. This would
allow fuel to evaporate into the
atmosphere. SeeMalfunction
Indicator Lamp on page 5-19.
If the vehicle has a Driver
Information Center (DIC), the
TIGHTEN GAS CAP message
displays if the fuel cap is not
properly installed.{Warning
If a fire starts while you are
refueling, do not remove the
nozzle. Shut off the flow of fuel by
shutting off the pump or by
notifying the station attendant.
Leave the area immediately.
Notice: If a new fuel cap is
needed, be sure to get the right
type of cap from your dealer. The
wrong type of fuel cap might not
fit properly, might cause the
malfunction indicator lamp to
light, and could damage the fuel
tank and emissions system. See
Malfunction Indicator Lamp on
page 5-19.
Filling a Portable Fuel
Container
{Warning
Filling a portable fuel container
while it is in the vehicle can cause
fuel vapors that can ignite either
by static electricity or other
means. You or others could be
badly burned and the vehicle
could be damaged. Always:
.Use approved fuel
containers.
.Remove the container from
the vehicle, trunk, or pickup
bed before filling.
.Place the container on the
ground.
(Continued)
Black plate (60,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
9-60 Driving and Operating
Warning (Continued)
.Place the nozzle inside the fill
opening of the container
before dispensing fuel, and
keep it in contact with the fill
opening until filling is
complete.
.Fill the container no more
than 95% full to allow for
expansion.
.Do not smoke, light matches,
or use lighters while
pumping fuel.
.Avoid using cell phones or
other electronic devices.
Towing
General Towing
Information
Only use towing equipment that has
been designed for the vehicle.
Contact your dealer or trailering
dealer for assistance with preparing
the vehicle for towing a trailer. Read
the entire section before towing a
trailer.
For towing a disabled vehicle, see
Towing the Vehicle on page 10-80.
For towing the vehicle behind
another vehicle such as a motor
home, seeRecreational Vehicle
Towing on page 10-81.
Driving Characteristics
and Towing Tips
Driving with a Trailer
When towing a trailer:
.Become familiar with the state
and local laws that apply to
trailer towing.
.Do not tow a trailer during the
first 800 km (500 mi) to prevent
damage to the engine, axle,
or other parts.
.Then during the first 800 km
(500 mi) of trailer towing, do not
drive over 80 km/h (50 mph) and
do not make starts at full throttle.
.Vehicles can tow in D (Drive).
Shift the transmission to a lower
gear if the transmission shifts
too often under heavy loads and/
or hilly conditions.
{Warning
When towing a trailer, exhaust
gases may collect at the rear of
the vehicle and enter if the
liftgate, trunk/hatch, or rear-most
window is open.
When towing a trailer:
.Do not drive with the liftgate,
trunk/hatch, or rear-most
window open.
(Continued)
Black plate (69,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
Driving and Operating 9-69
The seven-wire harness contains
the following trailer circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn
Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red: Battery Feed*
.Dark Blue: Trailer Brake*
*The fuses for these two circuits are
installed in the underhood electrical
center, but the wires are not
connected. They should be
connected by your dealer or a
qualified service center. Heavy-Duty Trailer Wiring Harness
Package
The vehicle is equipped with the
seven-wire trailer towing harness.
This harness with a seven-pin
universal trailer connector is
attached to a bracket on the hitch
platform.
The seven-wire harness contains
the following trailer circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn
Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red: Battery Feed*
.Dark Blue: Trailer Brake*
*The fuses for these two circuits are
installed in the underhood electrical
center, but the wires are not
connected. They should be
connected by your dealer or a
qualified service center.
If charging a remote (non-vehicle)
battery, press the tow/haul mode
button located at the end of the shift
lever. This will boost the vehicle
system voltage and properly charge
the battery. If the trailer is too light
for tow/haul mode, turn on the
headlamps as a second way to
boost the vehicle system and
charge the battery.
Black plate (70,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
9-70 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 near the
data link connector 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
It should be installed by your dealer
or a qualified service center.
If the vehicle is equipped with an
ITBC, 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 9-32 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” earlier in
the section. Tow/Haul is most useful
under the following driving
conditions:
.When pulling a heavy trailer or a
large or heavy load through
rolling terrain.
.When pulling a heavy trailer or a
large or heavy load in stop and
go traffic.
.When pulling a heavy trailer or a
large or heavy load in busy
parking lots where improved low
speed control of the vehicle is
desired.
Black plate (71,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
Driving and Operating 9-71
Operating the vehicle in Tow/Haul
when lightly loaded or with no trailer
at all will not cause damage.
However, there is no benefit to the
selection of Tow/Haul when the
vehicle is unloaded. Such a
selection when unloaded may result
in unpleasant engine and
transmission driving characteristics
and reduced fuel economy. Tow/
Haul is recommended only when
pulling a heavy trailer or a large or
heavy load.
Integrated Trailer Brake
Control System
The vehicle may have an Integrated
Trailer Brake Control (ITBC) system
for electric trailer brakes.This symbol is located on the Trailer
Brake Control Panel on vehicles
with an Integrated Trailer Brake
Control System. The power output
to the trailer brakes is based on the
amount of brake pressure being
applied by the vehicle’s brake
system. This available power output
to the trailer brakes can be adjusted
to a wide range of trailering
situations.
The ITBC system is integrated with
the vehicle’
s brake, anti-lock brake
and StabiliTrak systems. In trailering
conditions that cause the vehicle’s
anti-lock brake or StabiliTrak
systems to activate, power sent to
the trailer's brakes will be
automatically adjusted to minimize
trailer wheel lock-up. This does not
imply that the trailer has the
StabiliTrak system.
The vehicle may have a Trailer
Sway Control (TSC) feature. See
Trailer Sway Control (TSC) on
page 9-76. The vehicle may have a Hill Start
Assist (HSA) feature. See
Hill Start
Assist (HSA) on page 9-41.
If the vehicle’s brake, anti-lock
brake or StabiliTrak systems are not
functioning properly, the ITBC
system may not be fully functional
or may not function at all. Make sure
all of these systems are fully
operational to ensure full
functionality of the ITBC system.
The ITBC system is powered
through the vehicle's electrical
system. Turning the ignition off will
also turn off the ITBC system. The
ITBC system is fully functional only
when the ignition is in ON or
in RUN.
The ITBC system can only be used
with trailers with electric brakes.
Black plate (77,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
Driving and Operating 9-77
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. SeeStabiliTrak
®System on
page 9-42.
{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
(Continued)
Warning (Continued)
Equipment on page 9-67 for
trailer ratings and hitch setup
recommendations.
Adding non-dealer accessories can
affect the vehicle performance. See
Accessories and Modifications on
page 10-3.
Conversions and
Add-Ons
Add-On Electrical
Equipment
Notice: Some electrical
equipment can damage the
vehicle or cause components to
not work and would not be
covered by the warranty. Always
check with your dealer before
adding electrical equipment.
Add-on equipment can drain the
vehicle's 12-volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see
Servicing the Airbag-Equipped
Vehicle on page 3-38 andAdding
Equipment to the Airbag-Equipped
Vehicle on page 3-38.
Black plate (13,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
Vehicle Care 10-13
6. If the fluid level is in theacceptable range, push the
dipstick back in all the way, then
flip the handle down to lock the
dipstick in place.
Consistency of Readings
Always check the fluid level at least
twice using the procedure described
previously. Consistency (repeatable
readings) is important to maintaining
proper fluid level. If readings are still
inconsistent, contact the dealer.
Engine Air Cleaner/Filter
See Engine Compartment Overview
on page 10-5 for the location of the
engine air cleaner/filter.
Inspect the air cleaner/filter at the
scheduled maintenance intervals
and replace it at the first oil change
after each 80 000 km (50,000 mi)
interval. See Maintenance Schedule
on page 11-2 for more information.
If driving on dusty/dirty conditions,
inspect the filter at each engine oil
change.
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/filter,
remove the engine air cleaner/filter
from the vehicle by following
Steps 1 through 6. When the engine
air cleaner/filter is removed, lightly
shake it to release loose dust and
dirt. If the engine air cleaner/filter
remains covered with dirt, a new
filter is required. Never use
compressed air to clean the filter.
Replacing the Engine Air Cleaner/
Filter
1. Locate the air cleaner/filter assembly. See Engine
Compartment Overview on
page 10-5.
2. Loosen the four screws on the cover of the housing and lift up
the cover.
Black plate (22,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
10-22 Vehicle Care
{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. 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.