2018 GMC YUKON XL engine

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 235.
To slow down in small
increments, briefly press SET – .
For each press, the vehicle goes
about 1.6 km/h (1 mph) slower.
The speedometer reading can be
displayed in either English or metric
units. See Instrument Cluster 0 133 .
The increment value used depends
on the units displayed.
Passing Another Vehicle While
Using Cruise Control
Use the accelerator pedal to
increase the vehicle speed. When
you take your foot off the pedal, the
vehicle will slow down to the
previous set cruise speed. While
pressing the accelerator pedal or
shortly following the release to
override cruise control, briefly
pressing SET – will result in cruise
control set to the current vehicle
speed.
Using Cruise Control on Hills
How well the cruise control works
on hills depends on the vehicle
speed, the load, and the steepness
of the hills. When going up steep
hills, pressing the accelerator pedal may be necessary to maintain
vehicle speed. When going
downhill, Cruise Grade Braking
helps maintain the driver selected
speed.
Cruise Grade Braking is enabled
when the vehicle is started and
cruise control is active. It is not
enabled in Range Selection Mode.
It assists in maintaining driver
selected speed when driving on
downhill grades by using the engine
and transmission to slow the
vehicle.
To disable and enable Cruise Grade
Braking for the current ignition key
cycle, press and hold the Tow/Haul
button for five seconds. A DIC
message displays.
For other forms of Grade Braking,
see Automatic Transmission 0 216
and Tow/Haul Mode 0 222 .
Ending Cruise Control
There are four ways to end cruise
control:
.
Step lightly on the brake pedal.
.
Press
* . .
Shift the transmission to
N (Neutral).
.
To turn off cruise control,
press
5 .
Erasing Speed Memory
The cruise control set speed is
erased from memory if
5 is pressed
or if the ignition is turned off.
Adaptive Cruise Control If equipped with Adaptive Cruise
Control (ACC), it allows for selecting
the cruise control set speed and
following gap. Read this entire
section before using this system.
ACC uses a camera and radar
sensors to detect other vehicles.
See Radio Frequency Statement
0 396 . The following gap is the
following time (or distance) between
your vehicle and a vehicle detected
directly ahead in your path, moving
in the same direction. If no vehicle
is detected in your path, ACC works
like regular cruise control.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
254 Driving and Operating .
Sudden lighting changes, such
as when driving through tunnels.
.
Banked roads.
.
Roads with poor lane markings,
such as two-lane roads.
If the LKA system is not functioning
properly when lane markings are
clearly visible, cleaning the
windshield may help.
A system unavailable message may
display if the camera is blocked.
The LKA system does not need
service.
LKA assistance and/or LDW alerts
may occur due to tar marks,
shadows, cracks in the road,
temporary or construction lane
markings, or other road
imperfections. This is normal system
operation; the vehicle does not need
service. Turn LKA off if these
conditions continue. Fuel GM recommends the use of TOP
TIER ®
detergent gasoline to keep
the engine cleaner and reduce
engine deposits. See
www.toptiergas.com for a list of TOP
TIER detergent gasoline marketers
and applicable countries.
If the vehicle has a yellow sticker on
the fuel door, E85 or FlexFuel can
be used. See E85 or FlexFuel
0 256 .
For the L83 5.3L V8 engine, use
regular unleaded gasoline meeting
ASTM specification D4814 with a
posted octane rating of 87 or higher. Do not use gasoline with a posted
octane rating of less than 87, as this
may cause engine knock and will
lower fuel economy.
For the L86 6.2L V8 engine,
premium unleaded gasoline meeting
ASTM specification D4814 with a
posted octane rating of 93 is highly
recommended for best performance
and fuel economy. Unleaded
gasoline with an octane rated as low
as 87 can be used. Using unleaded
gasoline rated below 93 octane,
however, will lead to reduced
acceleration and fuel economy.
If knocking occurs, use a gasoline
rated at 93 octane as soon as
possible, otherwise, the engine
could be damaged. If heavy
knocking is heard when using
gasoline with a 93 octane rating, the
engine needs service.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 255Prohibited Fuels
CautionDo not use fuels with any of the
following conditions; doing so
may damage the vehicle and void
its warranty:
.
For vehicles which are not
FlexFuel, fuel labeled
greater than 15% ethanol by
volume, such as mid-level
ethanol blends (16 – 50%
ethanol), E85, or FlexFuel.
.
Fuel with any amount of
methanol, methylal, and
aniline. These fuels can
corrode metal fuel system
parts or damage plastic and
rubber parts.
.
Fuel containing metals such
as methylcyclopentadienyl
manganese tricarbonyl
(MMT), which can damage
the emissions control
system and spark plugs.
(Continued) Caution (Continued) .
Fuel with a posted octane
rating of less than the
recommended fuel. Using
this fuel will lower fuel
economy and performance,
and may decrease the life of
the emissions catalyst.
California Fuel
Requirements If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that
meet California specifications. See
the underhood emission control
label. If this fuel is not available in
states adopting California Emissions
Standards, the vehicle will operate
satisfactorily on fuels meeting
federal specifications, but emission
control system performance may be
affected. The malfunction indicator
lamp could turn on and the vehicle
may not pass a smog-check test.
See Malfunction Indicator Lamp
(Check Engine Light) 0 143 . If this occurs, return to your authorized
dealer for diagnosis. If it is
determined that the condition is
caused by the type of fuel used,
repairs may not be covered by the
vehicle warranty.
Fuels in Foreign
Countries The U.S., Canada, and Mexico post
fuel octane ratings in anti-knock
index (AKI). For fuel not to use in a
foreign country, see “ Prohibited
Fuels ” in Fuel 0 254 .
Fuel Additives To keep fuel systems clean, TOP
TIER detergent gasoline is
recommended. See Fuel 0 254 .
If TOP TIER detergent gasoline is
not available, one bottle of GM Fuel
System Treatment Cleaner added to
the fuel tank at every engine oil
change, can help. GM Fuel System
Treatment Cleaner is the only
gasoline additive recommended by
General Motors. It is available at
your dealer.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
256 Driving and Operating If your vehicle is able to use E85 or
FlexFuel, GM Fuel System
Treatment Cleaner - FlexFuel is the
only recommended additive for use.
Do not use any other additives with
an E85 or FlexFuel vehicle. See
E85 or FlexFuel 0 256 .
E85 or FlexFuel Vehicles marked as “ E85 ” or
FlexFuel can use either unleaded
gasoline or ethanol fuel containing
up to 85% ethanol (E85). All other
vehicles should use only the
unleaded gasoline as described in
Fuel 0 254 .
The use of E85 or FlexFuel is
encouraged when the vehicle is
designed to use it. E85 or FlexFuel
is made from renewable sources.
Many fuel stations will not have an
85% ethanol fuel (E85) pump
available. Those stations that do
have E85 should have a label
indicating the FlexFuel ethanol
content. Do not use the fuel if the
ethanol content is greater than 85%. The starting characteristics of E85
or FlexFuel make it unsuitable for
use when temperatures fall below
− 18 °C (0 °F). Use gasoline or add
gasoline to the E85 or FlexFuel.
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 0 256 .
CautionSome additives are not
compatible with E85 or FlexFuel
and can harm the vehicle's fuel
system. Do not add anything to
E85 or FlexFuel. Damage caused
by additives would not be covered
by the vehicle warranty.
Caution
Do not use fuel containing
methanol. It can corrode metal
parts in the fuel system and also
(Continued) Caution (Continued) damage plastic and rubber parts.
That damage would not be
covered under the vehicle
warranty.
Filling the Tank
{ WarningFuel 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.
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 257Warning (Continued).
Do not use a cell phone
while refueling.
.
Do not reenter the vehicle
while pumping fuel.
.
Keep children away from
the fuel pump and never let
children pump fuel.
.
Fuel can spray out if the
refueling nozzle is inserted
too quickly. This spray can
happen if the tank is nearly
full, and is more likely in hot
weather. Insert the refueling
nozzle slowly and wait for
any hiss noise to stop prior
to beginning to flow fuel. To open the fuel door, push and
release the rearward center edge of
the door.
The vehicle has a capless refueling
system and does not have a fuel
cap. The filling nozzle must be fully
inserted and latched prior to starting
fuel flow. { WarningOverfilling the fuel tank by more
than three clicks of a standard fill
nozzle may cause:
.
Vehicle performance issues,
including engine stalling and
damage to the fuel system.
.
Fuel spills.
.
Potential fuel fires.
Be careful not to spill fuel. Wait a
few seconds after you have finished
pumping before removing the
nozzle. Clean fuel from painted
surfaces as soon as possible. See
Exterior Care 0 360 .
{ 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 259
Trailer 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 0 355 . For
towing the vehicle behind another
vehicle such as a motor home, see
Recreational Vehicle Towing 0 355 .
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. These
requirements vary from state to
state. .
The trailer must be equipped
with brakes adequate for the
intended use. A loaded trailer
weighing more than 900 kg
(2,000 lb) must be equipped with
its own brake system, with
brakes working on all axles.
Trailer braking equipment
conforming to Canadian
Standards Association (CSA)
requirement CAN3-D313, or its
equivalent, is recommended.
.
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.
.
Do not use Adaptive Cruise
Control when towing. .
Turn off Parking Assist and Rear
Cross Traffic Alert (RTCA) when
towing.
.
The Forward Automatic Braking
System should be set to Off
when towing. See Forward
Automatic Braking (FAB) 0 21 .
.
Turn off Lane Keep Assist (LKA)
when towing. See Lane Keep
Assist (LKA) 0 252 .
{ WarningWhen 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.
.
Fully open the air outlets on
or under the instrument
panel.
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
260 Driving and Operating Warning (Continued).
Also adjust the climate
control system to a setting
that brings in only outside
air. See “ Climate Control
Systems ” in the Index.
For more information about
carbon monoxide, see Engine
Exhaust 0 215 .
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.
The structure, tires, and brakes of
the trailer must be rated to carry the
load. Inadequate trailer equipment
can cause the combination to
operate in an unexpected or unsafe
manner.
Before starting, check all trailer hitch
parts and attachments, safety
chains, electrical connectors, lamps,
tires, and mirrors. Get familiar with the handling and braking of the rig.
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 to the 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
CautionMaking 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 261Driving on Grades Reduce speed and shift to a lower
gear before 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.
When towing, use the Tow/Haul
Mode to prevent damage to the
engine or transmission. See Tow/
Haul Mode 0 222 .
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
transmission in P (Park) for a few minutes before turning the engine
off. If the overheat warning comes
on, see Engine Overheating 0 294 .
Parking on Hills
{ WarningParking 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.
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule 0 370 .
Things that are especially important
in trailer operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system, and