fuel GMC YUKON XL 2018 Owner's Guide

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
226 Driving and Operating 4. Turn the transfer case knob to
the desired setting.
After the transfer case has
shifted out of N (Neutral), the
N (Neutral) light will go out.
5. Release the parking brake.
6. Start the engine and shift the
transmission to the
desired gear.
Single Speed Automatic
Transfer Case
Use the transfer case knob, next to
the steering wheel, to shift into and
out of four-wheel drive for extra
traction. All of the lights will blink on then off
momentarily when the ignition is
turned on. The light that remains on
will indicate the state of the
transfer case.
If the indicator mark on the switch
does not match up with the light
then that likely means the switch
was moved when the ignition
was off.
The indicator mark on the switch
must line up with the indicator light
before a shift can be commanded.
To command a shift rotate the
transfer case switch to the new
desired position. The light will blink
meaning that the shift is in progress.
When the shift is completed the new
position will be illuminated. If the
transfer case can not complete a
shift command, it will go back to its
last chosen setting.
The settings are:
2
m (Two-Wheel Drive High) : Use
for driving on most streets and
highways. The front axle is not
engaged. This setting provides the
best fuel economy. AUTO (Automatic Four-Wheel
Drive) : Use when road surface
traction conditions are variable.
When driving in AUTO, the front
axle is engaged, and the vehicle's
power is sent to the front and rear
wheels automatically based on
driving conditions. This setting
provides slightly lower fuel economy
than 2
m .
Do not use AUTO mode to park on
a steep grade with poor traction
such as ice, snow, mud, or gravel.
In AUTO mode only rear wheels will
hold the vehicle from sliding when
parked. If parking on a steep grade,
use 4
m to keep all four wheels
engaged.
4
m (Four-Wheel Drive High) : Use
this position when extra traction is
needed, such as when driving on
snowy or icy roads, when
off-roading, or when plowing snow.

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
258 Driving and Operating Filling the Tank with a Portable
Gas Can
If the vehicle runs out of fuel and
must be filled from a portable
gas can:
1. Locate the capless funnel
adapter from inside the vehicle.
2. Insert and latch the funnel into
the capless fuel system.
{ Warning
Attempting to refuel without using
the funnel adapter may cause fuel
spillage and damage the capless
fuel system. This could cause a
fire and you or others could be
badly burned and the vehicle
could be damaged. 3. Remove and clean the funnel
adapter and return to the
storage location.
Filling a Portable Fuel
Container
{ WarningFilling 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.
.
Place the nozzle inside the
fill opening of the container
before dispensing fuel, and
(Continued) Warning (Continued) 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
262 Driving and Operating 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.
See New Vehicle Break-In 0 204 .
Before towing a trailer, see
"Hands-Free Operation" under
Liftgate 0 43 .
{ WarningThe 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
or the trailer brakes are
inadequate for the load, the
vehicle may not stop as expected.
The driver and passengers could
be seriously injured. The vehicle
may also be damaged; the
resulting repairs would not be
(Continued) Warning (Continued) 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.
CautionPulling 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 ” following.
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.
The following information has many
time-tested, important trailering tips
and safety rules. Many of these are
important for your safety and that of
your passengers. So please read
this section carefully before pulling a
trailer.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 269Pressing this button at the end of
the shift lever turns on and off the
Tow/Haul Mode.
This indicator light on the instrument
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 0 222 .
Tow/Haul is designed to be most
effective when the vehicle and
trailer combined weight is at least
75 % of the vehicle's Gross
Combined Weight Rating (GCWR).
See “ Weight of the Trailer ” under
Trailer Towing 0 262 . 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.
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 use with electric trailer brakes or
most electric-over-hydraulic trailer
brakes.
This symbol is on the Trailer Brake
Control Panel on vehicles with an
ITBC system. The power output to
the trailer brakes is based on the
amount of brake pressure being
applied by the vehicle ’ s brake
system, and on the type of trailer
brakes detected. 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, antilock brake,
and StabiliTrak systems. In trailering
conditions that cause the vehicle ’ s

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
312 Vehicle Care Fuses Usage
4 Passenger
motorized seat belt
5 Suspension
leveling
compressor
6 4WD transfer case
electronic control
7 –
8 –
10 Electric parking
brake/ –
11 –
12 –
13 Interior BEC LT2
14 Rear BEC 1
15 –
16 –
17 Driver motorized
seat belt
18 –
19 –
20 – Fuses Usage
21 Automatic
headlamp leveling/
Exhaust solenoid
22 Fuel pump
23 Integrated chassis
control module
24 Real time
dampening
25 Fuel pump power
module
26 – /Battery regulated
voltage control
27 –
28 Upfitter 2
30 Wiper
31 Trailer interface
module
32 –
33 –
34 Reverse lamps
35 Antilock brake
system valve
36 Trailer brakes Fuses Usage
38 –
39 Right trailer
stoplamp/Turn
signal lamp
40 Left trailer
stoplamp/turn
signal lamp
41 Trailer parking
lamps
42 Right parking
lamps
43 Left parking lamps
44 Upfitter 3
45 Automatic level
control/Run/Crank
46 –
47 Upfitter 4
49 Reverse lamps
50 –
52 –
53 –
54 –

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 313Fuses Usage
55 –
56 –
57 –
58 –
59 Euro trailer
60 Air conditioning
control
61 –
62 –
63 Upfitter 1
64 –
65 –
66 –
67 Trailer battery
68 Secondary
fuel pump
69 RC upfitter 3 and 4
70 VBAT
upfitter 3 and 4
71 –
73 – Fuses Usage
74 Engine control
module/Ignition
75 Miscellaneous/
Ignition/ –
76 Transmission/
Ignition
77 RC upfitter 1 and 2
78 VBAT
upfitter 1 and 2
79 –
80 –
81 –
82 –
83 Euro trailer/RC
85 –
86 –
87 Engine
88 Injector A – odd
89 Injector B – even
90 O2 sensor B
91 Throttle control Fuses Usage
93 Horn
94 Fog lamps
95 High-beam
headlamps
96 –
97 –
98 –
99 –
100 O2 sensor A
101 Engine control
module
102 Engine control
module/
Transmission
control module
103 Auxiliary interior
heater
104 Starter
105 –
106 –
107 Aeroshutter
108 –