2018 GMC YUKON XL service

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
296 Vehicle Care
Engine Fan 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. The
fans 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.
Washer Fluid What to Use
When windshield washer fluid needs
to be added, be sure to read the
manufacturer's instructions before
use. Use a fluid that has sufficient protection against freezing in an
area where the temperature may fall
below freezing.
Adding Washer Fluid The vehicle has a low washer fluid
message on the DIC that comes on
when the washer fluid is low. The
message is displayed for
15 seconds at the start of each
ignition cycle. When the WASHER
FLUID LOW ADD FLUID message
displays, washer fluid will need to
be added to the windshield washer
fluid reservoir.
Open the cap with the washer
symbol on it. Add washer fluid until
the tank is full. See Engine
Compartment Overview 0 280 for
reservoir location. Caution .
Do not use washer fluid that
contains any type of water
repellent coating. This can
cause the wiper blades to
chatter or skip.
.
Do not use engine coolant
(antifreeze) in the
windshield washer. It can
damage the windshield
washer system and paint.
.
Do not mix water with
ready-to-use washer fluid.
Water can cause the
solution to freeze and
damage the washer fluid
tank and other parts of the
washer system.
.
When using concentrated
washer fluid, follow the
manufacturer instructions for
adding water.
.
Fill the washer fluid tank
only three-quarters full when
it is very cold. This allows
for fluid expansion if
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 297Caution (Continued) freezing occurs, which could
damage the tank if it is
completely full.
Brakes Disc brake pads have built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn and new pads are needed.
The sound can come and go or can
be heard all the time when the
vehicle is moving, except when
applying the brake pedal firmly.
{ 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. CautionContinuing 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. See Capacities and
Specifications 0 384 .
Brake pads should be replaced as
complete 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 may be required. Replacing Brake System Parts Always replace brake system parts
with new, approved replacement
parts. If this is not done, the brakes
may not work properly. The braking
performance expected can change
in many other ways if the wrong
replacement brake parts are
installed or if parts are improperly
installed.
Brake Fluid
The brake master cylinder reservoir
is filled with GM approved DOT 3
brake fluid as indicated on the
reservoir cap. See Engine
Compartment Overview 0 280 for
the location of the reservoir.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
302 Vehicle Care to its sale or delivery to the
ultimate purchaser or while it is
in use; or
2. The use of the vehicle after
such device or element of
design has been removed or
rendered inoperative by any
person.
Among those acts presumed to
constitute tampering are the acts
listed below.
Insulation:
Removal of the noise shields or any
underhood insulation.
Engine:
Removal or rendering engine speed
governor, if the vehicle has one,
inoperative so as to allow engine
speed to exceed manufacturer
specifications.
Fan and Drive:
.
Removal of fan clutch, if the
vehicle has one, or rendering
clutch inoperative.
.
Removal of the fan shroud, if the
vehicle has one. Air Intake:
.
Removal of the air cleaner
silencer.
.
Modification of the air cleaner.
Exhaust:
.
Removal of the muffler and/or
resonator.
.
Removal of the exhaust pipes
and exhaust pipe clamps.
Starter Switch Check
{ WarningWhen you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be
sure there is enough room
around the vehicle.
2. Apply both the parking brake
and the regular brake. Do not use the accelerator
pedal, and be ready to turn off
the engine immediately if it
starts.
3. Try to start the engine in each
gear. The vehicle should start
only in P (Park) or N (Neutral).
If the vehicle starts in any other
position, contact your dealer for
service.
Automatic Transmission
Shift Lock Control
Function Check
{ WarningWhen you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be
sure there is enough room
around the vehicle. It should be
parked on a level surface.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 3032. Apply the parking brake. Be
ready to apply the regular
brake immediately if the vehicle
begins to move.
3. With the engine off, turn the
ignition on, but do not start the
engine. Without applying the
regular brake, try to move the
shift lever out of P (Park) with
normal effort. If the shift lever
moves out of P (Park), contact
your dealer for service.
Ignition Transmission
Lock Check If equipped with a Key Access
ignition, while parked and with the
parking brake set, try to turn the
ignition off in each shift lever
position.
.
The ignition should turn off only
when the shift lever is in
P (Park).
.
The key should come out only
when the ignition is off.
Contact your dealer if service is
required. Park Brake and P (Park)
Mechanism Check
{ WarningWhen you are doing this check,
the vehicle could begin to move.
You or others could be injured
and property could be damaged.
Make sure there is room in front
of the vehicle in case it begins to
roll. Be ready to apply the regular
brake at once should the vehicle
begin to move.
Park on a fairly steep hill, with the
vehicle facing downhill. Keeping
your foot on the regular brake, set
the parking brake.
.
To check the parking brake's
holding ability: With the engine
running and the transmission in
N (Neutral), slowly remove foot
pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only. .
To check the P (Park)
mechanism's holding ability:
With the engine running, shift to
P (Park). Then release the
parking brake followed by the
regular brake.
Contact your dealer if service is
required.
Wiper Blade Replacement Windshield wiper blades should be
inspected for wear or cracking.
For the proper type and size, see
Maintenance Replacement Parts
0 380 .
Front Wiper Blade
Replacement To replace the wiper blade
assembly:
1. Pull the windshield wiper
assembly away from the
windshield.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 305Driver Assistance Systems When a windshield replacement is
needed and the vehicle is equipped
with a front-looking camera sensor
for the Driver Assistance Systems,
the windshield must be installed
according to GM specifications for
these systems to work properly. If it
is not, there may be unexpected
behavior and/or messages from
these systems.
Gas Strut(s) This vehicle is equipped with gas
strut(s) to provide assistance in
lifting and holding open the hood/
trunk/liftgate system in full open
position.
{ Warning
If the gas struts that hold open
the hood, trunk, and/or liftgate fail,
you or others could be seriously
injured. Take the vehicle to your
dealer for service immediately.
Visually inspect the gas struts for
(Continued) Warning (Continued) signs of wear, cracks, or other
damage periodically. Check to
make sure the hood/trunk/liftgate
is held open with enough force.
If struts are failing to hold the
hood/trunk/liftgate, do not
operate. Have the vehicle
serviced.
CautionDo not apply tape or hang any
objects from gas struts. Also do
not push down or pull on gas
struts. This may cause damage to
the vehicle.
See Maintenance Schedule 0 370 . Hood
Trunk

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
306 Vehicle Care
Liftgate
Headlamp Aiming Headlamp aim has been preset and
should need no further adjustment.
If the vehicle is damaged in a crash,
the headlamp aim may be affected.
If adjustment to the headlamps is
necessary, see your dealer.
Bulb Replacement For the proper type of replacement
bulbs, or any bulb changing
procedure not listed in this section,
contact your dealer.
High Intensity Discharge
(HID) Lighting
{ WarningThe High Intensity Discharge
(HID) lighting system operates at
a very high voltage. If you try to
service any of the system
components, you could be
seriously injured. Have your
dealer or a qualified technician
service them.
After an HID headlamp bulb has
been replaced, the beam might be a
slightly different shade than it was
originally. This is normal.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
320 Vehicle Care Fuses Usage
17 Liftglass
18 Rear fog lamp (if
equipped)
19 Rear fog lamp (if
equipped)
20 Heated mirror
Relays Usage
1 Rear window
defogger
Wheels and Tires Tires Every new GM vehicle has
high-quality tires made by a
leading tire manufacturer. See
the warranty manual for
information regarding the tire
warranty and where to get
service. For additional
information refer to the tire
manufacturer.
{ Warning.
Poorly maintained and
improperly used tires are
dangerous. .
Overloading the tires can
cause overheating as a
result of too much
flexing. There could be a
blowout and a serious
crash. See Vehicle Load
Limits 0 200 .
(Continued) Warning (Continued) .
Underinflated tires pose
the same danger as
overloaded tires. The
resulting crash could
cause serious injury.
Check all tires frequently
to maintain the
recommended pressure.
Tire pressure should be
checked when the tires
are cold. .
Overinflated tires are
more likely to be cut,
punctured, or broken by
a sudden impact — such
as when hitting a pothole.
Keep tires at the
recommended pressure.
.
Worn or old tires can
cause a crash. If the
tread is badly worn,
replace them.
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 321Warning (Continued).
Replace any tires that
have been damaged by
impacts with potholes,
curbs, etc..
Improperly repaired tires
can cause a crash. Only
the dealer or an
authorized tire service
center should repair,
replace, dismount, and
mount the tires..
Do not spin the tires in
excess of 56 km/h
(35 mph) on slippery
surfaces such as snow,
mud, ice, etc. Excessive
spinning may cause the
tires to explode.
See Tire Pressure for
High-Speed Operation 0 328 for
inflation pressure adjustment for
high-speed driving. All-Season Tires This vehicle may come with
all-season tires. These tires are
designed to provide good overall
performance on most road surfaces
and weather conditions. Original
equipment tires designed to GM's
specific tire performance criteria
have a TPC specification code
molded onto the sidewall. Original
equipment all-season tires can be
identified by the last two characters
of this TPC code, which will
be “ MS. ”
Consider installing winter tires on
the vehicle if frequent driving on
snow or ice-covered roads is
expected. All-season tires provide
adequate performance for most
winter driving conditions, but they
may not offer the same level of
traction or performance as winter
tires on snow or ice-covered roads.
See Winter Tires 0 321 .
Winter Tires This vehicle was not originally
equipped with winter tires. Winter
tires are designed for increased traction on snow and ice-covered
roads. Consider installing winter
tires on the vehicle if frequent
driving on ice or snow covered
roads is expected. See your dealer
for details regarding winter tire
availability and proper tire selection.
Also, see Buying New Tires 0 335 .
With winter tires, there may be
decreased dry road traction,
increased road noise, and shorter
tread life. After changing to winter
tires, be alert for changes in vehicle
handling and braking.
If using winter tires:
.
Use tires of the same brand and
tread type on all four wheel
positions.
.
Use only radial ply tires of the
same size, load range, and
speed rating as the original
equipment tires.
Winter tires with the same speed
rating as the original equipment tires
may not be available for H, V, W, Y,
and ZR speed rated tires. If winter