Black plate (57,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
Driving and Operating 9-57
Fuel Additives
To keep fuel systems clean, TOP
TIER Detergent Gasoline is
recommended. SeeFuel on
page 9-55.
If TOP TIER Detergent Gasoline is
not available, one bottle of Fuel
System Treatment PLUS, part
number 88861013, added to the fuel
tank at every engine oil change, can
help. Fuel System Treatment PLUS
is the only gasoline additive
recommended by General Motors.
It is available at your dealer.
Do not use additives with E85 or
FlexFuel.
E85 or FlexFuel
Vehicles with a yellow fuel cap can
use either unleaded gasoline or fuel
containing up to 85% ethanol (E85).
All other vehicles should use only
the unleaded gasoline as described
in Recommended Fuel on
page 9-55. The use of E85 or FlexFuel is
encouraged when the vehicle is
designed to use it. E85 or FlexFuel
is made from renewable sources.
To help locate fuel stations that
carry E85 or FlexFuel, the U.S.
Department of Energy has an
alternative fuels website. See
www.afdc.energy.gov/afdc/locator/
stations.
E85 or FlexFuel should meet ASTM
Specification D 5798 or CAN/
CGSB–3.512 in Canada. Do not use
the fuel if the ethanol content is
greater than 85%. Fuel mixtures that
do not meet ASTM or CGSB
specifications can affect driveability
and could cause the malfunction
indicator lamp to come on.
After refueling, the vehicle
calculates the composition of the
fuel. It is not recommended to
repeatedly switch between fuels.
If fuels are switched frequently, add
as much fuel as possible and do not
add less than 11 L (3 gal) when
refueling. Drive at least 11 km (7 mi)immediately after refueling to allow
the vehicle to adapt to the change in
ethanol concentration.
Because E85 or FlexFuel has less
energy per liter (gallon) than
gasoline, the vehicle will need to be
refilled more often. See
Filling the
Tank on page 9-58.
Notice: Some additives are not
compatible with E85 fuel and can
harm the vehicle's fuel system.
Do not add anything to E85.
Damage caused by additives
would not be covered by the
vehicle warranty.
Notice: This vehicle was not
designed for fuel that contains
methanol. Do not use fuel
containing methanol. It can
corrode metal parts in the fuel
system and also damage plastic
and rubber parts. That damage
would not be covered under the
vehicle warranty.
Black plate (58,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
9-58 Driving and Operating
Filling the Tank
{Warning
Fuel vapors and fuel fires burn
violently and can cause injury or
death.
.To help avoid injuries to you
and others, read and follow
all the instructions on the fuel
pump island.
.Turn off the engine when
refueling.
.Keep sparks, flames, and
smoking materials away
from fuel.
.Do not leave the fuel pump
unattended.
.Do not reenter the vehicle
while pumping fuel.
.Keep children away from the
fuel pump and never let
children pump fuel.(Continued)
Warning (Continued)
.Fuel can spray out if the fuel
cap is opened too quickly.
This spray can happen if the
tank is nearly full, and is
more likely in hot weather.
Open the fuel cap slowly and
wait for any hiss noise to stop
then unscrew the cap all
the way
The tethered fuel cap is located
behind a hinged fuel door on the
driver side of the vehicle. If the
vehicle has E85 fuel capability, the
fuel cap will be yellow and state that
E85 or gasoline can be used. See
E85 or FlexFuel on page 9-57.
To open the fuel door, push the
rearward center edge in and release
and it will open.
To remove the fuel cap, turn it
slowly counterclockwise. The fuel
cap has a spring in it; if the cap is
released too soon, it will spring back
to the right.
While refueling, hang the tethered
fuel cap from the hook on the
fuel door.
Be careful not to spill fuel. Do not
top off or overfill the tank and wait a
few seconds after you have finished
pumping before removing the
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 (61,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
Driving and Operating 9-61
Warning (Continued)
.Fully open the air outlets on
or under the instrument
panel.
.Also adjust the climate
control system to a setting
that brings in only outside air.
See“Climate Control System”
in the Index.
For more information about
Carbon Monoxide, see Engine
Exhaust on page 9-27.
Towing a trailer requires a certain
amount of experience. The
combination you are driving is
longer and not as responsive as the
vehicle itself. Get acquainted with
the handling and braking of the rig
before setting out for the open road.
Before starting, check all trailer hitch
parts and attachments, safety
chains, electrical connectors, lamps,
tires, and mirrors. If the trailer has
electric brakes, start the combination moving and then apply
the trailer brake controller by hand
to be sure the brakes work.
During the trip, check occasionally
to be sure that the load is secure
and the lamps and any trailer
brakes still work.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid heavy
braking and sudden turns.
Passing
More passing distance is needed
when towing a trailer. The
combination will not accelerate as
quickly and is longer so it is
necessary to go much farther
beyond the passed vehicle before
returning to the lane.
Backing Up
Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand tothe left. To move the trailer to the
right, move your hand to the right.
Always back up slowly and,
if possible, have someone
guide you.
Making Turns
Notice:
Making very sharp turns
while trailering could cause the
trailer to come in contact with the
vehicle. The vehicle could be
damaged. Avoid making very
sharp turns while trailering.
When turning with a trailer, make
wider turns than normal. Do this so
the trailer will not strike soft
shoulders, curbs, road signs, trees,
or other objects. Avoid jerky or
sudden maneuvers. Signal well in
advance.
If the trailer turn signal bulbs burn
out, the arrows on the instrument
cluster will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Black plate (62,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
9-62 Driving and Operating
Driving on Grades
Reduce speed and shift to a lower
gearbefore starting down a long or
steep downgrade. If the
transmission is not shifted down, the
brakes might get hot and no longer
work well.
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.
The Tow/Haul Mode may be used if
the transmission shifts too often.
See Tow/Haul Mode on page 9-32.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off
immediately after towing at high
altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
automatic transmission in P (Park) for a few minutes before turning the
engine off. If the overheat warning
comes on, see
Engine Overheating
on page 10-18.
Parking on Hills
{Warning
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.
If parking the rig on a hill:
1. Press the brake pedal, but do not shift into P (Park) yet. Turn
the wheels into the curb if facing
downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer wheels. 3. When the wheel chocks are in
place, release the regular brakes
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park).
5. Release the brake pedal.Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks.
7. Stop and have someone pick up and store the chocks.
Black plate (63,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
Driving and Operating 9-63
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule on
page 11-2. Things that are
especially important in trailer
operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system, and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Trailer Towing
Do not tow a trailer during break-in.
SeeNew Vehicle Break-In on
page 9-19 for more information.
{Warning
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly. For
example, if the trailer is too
heavy, the brakes may not work
well—or even at all. The driver
and passengers could be
seriously injured. The vehicle may
also be damaged; the resulting
repairs would not be covered by
the vehicle warranty. Pull a trailer
only if all the steps in this section
have been followed. Ask your
dealer for advice and information
about towing a trailer with the
vehicle. Notice:
Pulling a trailer
improperly can damage the
vehicle and result in costly
repairs not covered by the vehicle
warranty. To pull a trailer
correctly, follow the advice in this
section and see your dealer for
important information about
towing a trailer with the vehicle.
To identify the trailering capacity of
the vehicle, read the information in
“Weight of the Trailer” that appears
later in this section.
Trailering is different than just
driving the vehicle by itself.
Trailering means changes in
handling, acceleration, braking,
durability and fuel economy.
Successful, safe trailering takes
correct equipment, and it has to be
used properly.
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.