2018 GMC YUKON XL Owners Manual

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
272 Driving and Operating To adjust Trailer Gain for each
towing condition:
1. Drive the vehicle with the trailer
attached on a level road
surface representative of the
towing condition and free of
traffic at about 32 to 40 km/h
(20 to 25 mph) and fully apply
the Manual Trailer Brake apply
lever.
Adjusting Trailer Gain at
speeds lower than 32 to
40 km/h (20 to 25 mph) may
result in an incorrect gain
setting.
2. Adjust the Trailer Gain, using
the Trailer Gain adjustment
buttons, to just below the point
of trailer wheel lock-up,
indicated by trailer wheel
squeal or tire smoke when a
trailer wheel locks.
Trailer wheel lock-up may not
occur if towing a heavily loaded
trailer. In this case, adjust the
Trailer Gain to the highest
allowable setting for the towing
condition. 3. Readjust Trailer Gain any time
vehicle loading, trailer loading,
or road surface conditions
change or if trailer wheel
lock-up is noticed at any time
while towing.
Other ITBC-Related DIC Messages
In addition to displaying TRAILER
GAIN and OUTPUT through the
DIC, trailer connection and ITBC
system status are displayed on
the DIC.
TRAILER CONNECTED: This
message will briefly display when a
trailer with electric brakes is first
connected to the vehicle. This
message will automatically turn off
in about 10 seconds. This message
can be acknowledged before it
automatically turns off.
CHECK TRAILER WIRING: This
message will display if:
.
The ITBC system first
determines connection to a
trailer with electric brakes and
then the trailer harness becomes
disconnected from the vehicle. If the disconnect occurs while
the vehicle is stationary, this
message will automatically turn
off in about 30 seconds. This
message will also turn off if it is
acknowledged or if the trailer
harness is reconnected.
If the disconnect occurs while
the vehicle is moving, this
message will continue until the
ignition is turned off. This
message will also turn off if it is
acknowledged or if the trailer
harness is reconnected.
.
There is an electrical fault in the
wiring to the trailer brakes. This
message will continue as long
as there is an electrical fault in
the trailer wiring. This message
will also turn off if it is
acknowledged.
To determine if the electrical fault is
on the vehicle side or trailer side of
the trailer wiring harness
connection:
1. Disconnect the trailer wiring
harness from the vehicle.
2. Turn the ignition off.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 2733. Wait 10 seconds, then turn the
ignition back to RUN.
4. If the CHECK TRAILER
WIRING message reappears,
the electrical fault is on the
vehicle side.
If the CHECK TRAILER
WIRING message only
reappears when connecting the
trailer wiring harness to the
vehicle, the electrical fault is on
the trailer side.
SERVICE TRAILER BRAKE
SYSTEM: This message will display
when there is a problem with the
ITBC system. If this message
continues over multiple ignition
cycles, there is a problem with the
ITBC system. Have the vehicle
serviced.
If either the CHECK TRAILER
WIRING or SERVICE TRAILER
BRAKE SYSTEM message displays
while driving, the ITBC system may
not be fully functional or may not
function at all. When traffic
conditions allow, carefully pull the
vehicle over to the side of the road
and turn the ignition off. Check the wiring connection to the trailer and
turn the ignition back on. If either of
these messages continues, either
the vehicle or trailer needs service.
A GM dealer may be able to
diagnose and repair problems with
the trailer. However, any diagnosis
and repair of the trailer is not
covered under the vehicle warranty.
Contact your trailer dealer for
assistance with trailer repairs and
trailer warranty information.
Trailer Sway
Control (TSC) The vehicle has a Trailer Sway
Control (TSC) feature as part of the
StabiliTrak system. If TSC detects
that the trailer is swaying, the
vehicle's brakes are automatically
applied. When TSC is applying the brakes,
the TCS/StabiliTrak indicator light
flashes to notify the driver to reduce
speed. If the trailer continues to
sway, StabiliTrak will reduce engine
torque to help slow the vehicle.
TSC will not function if StabiliTrak is
turned off. See Traction Control/
Electronic Stability Control 0 229 .
Electronic Trailer Sway Control
Devices Some trailers may come equipped
with an electronic device designed
to reduce or control trailer sway.
Aftermarket equipment
manufacturers also offer similar
devices that connect to the wiring
between the trailer and the vehicle.
These devices may interfere with
the vehicle ’ s trailer brake or other
systems, including integrated
anti-sway systems, if equipped.
Messages related to trailer
connections or trailer brakes could
appear on the Driver Information
Center (DIC). The effect that these
devices may have on vehicle
handling or trailer brake
performance is unknown.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
274 Driving and Operating
{ WarningUse of electronic trailer sway
control devices could result in
reduced trailer brake
performance, loss of trailer
brakes, or other malfunctions, and
could cause a crash. You or
others could be injured or killed.
Before using one of these
devices:
.
Ask the device or trailer
manufacturer if the device
has been thoroughly tested
for compatibility with the
make, model, and year of
the vehicle as well as
optional equipment installed
on the vehicle.
.
Before driving on the open
roads, check that the trailer
brakes are working properly.
Drive the vehicle with the
trailer attached on a level
road surface that is free of
traffic at about 32-40 km/h
(20-25 mph) and fully apply
(Continued) Warning (Continued) the manual trailer brake
apply lever. Also check that
the trailer brake lamps and
other lamps are functioning
correctly.
.
If the trailer brakes are not
operating properly at any
time, or if a DIC message
indicates problems with the
trailer connections or trailer
brakes, carefully pull the
vehicle over to the side of
the road when traffic
conditions allow. Conversions and
Add-Ons Add-On Electrical
Equipment
{ WarningThe Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/
Maintenance testing. See
Malfunction Indicator Lamp
(Check Engine Light) 0 143 .
A device connected to the DLC —
such as an aftermarket fleet or
driver-behavior tracking device —
may interfere with vehicle
systems. This could affect vehicle
operation and cause a crash.
Such devices may also access
information stored in the vehicle ’ s
systems.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 275CautionSome electrical equipment can
damage the vehicle or cause
components to not work and
would not be covered by the
vehicle 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 0 95 and Adding Equipment
to the Airbag-Equipped Vehicle
0 95 .

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
276 Vehicle Care
Vehicle Care General Information General Information . . . . . . . . . . 277
California Proposition
65 Warning . . . . . . . . . . . . . . . . . 277
California Perchlorate
Materials Requirements . . . . . 278
Accessories and
Modifications . . . . . . . . . . . . . . . . 278
Vehicle Checks Doing Your Own
Service Work . . . . . . . . . . . . . . . 278
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 279
Engine Compartment
Overview . . . . . . . . . . . . . . . . . . . . 280
Engine Oil . . . . . . . . . . . . . . . . . . . . 283
Engine Oil Life System . . . . . . . 285
Automatic Transmission Fluid
(6 Speed Transmission) . . . . . 286
Automatic Transmission Fluid
(8 and 10 Speed
Transmission) . . . . . . . . . . . . . . . 289
Engine Air Cleaner/Filter . . . . . . 290
Cooling System . . . . . . . . . . . . . . 291
Engine Overheating . . . . . . . . . . 294
Engine Fan . . . . . . . . . . . . . . . . . . . 296
Washer Fluid . . . . . . . . . . . . . . . . . 296
Brakes . . . . . . . . . . . . . . . . . . . . . . . 297 Brake Fluid . . . . . . . . . . . . . . . . . . . 297
Battery - North America . . . . . . 298
Four-Wheel Drive . . . . . . . . . . . . . 299
Front Axle . . . . . . . . . . . . . . . . . . . . 300
Rear Axle . . . . . . . . . . . . . . . . . . . . 300
Noise Control System . . . . . . . . 301
Starter Switch Check . . . . . . . . . 302
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 302
Ignition Transmission Lock
Check . . . . . . . . . . . . . . . . . . . . . . . 303
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . 303
Wiper Blade Replacement . . . . 303
Glass Replacement . . . . . . . . . . 304
Windshield Replacement . . . . . 304
Gas Strut(s) . . . . . . . . . . . . . . . . . . 305
Headlamp Aiming Headlamp Aiming . . . . . . . . . . . . 306
Bulb Replacement Bulb Replacement . . . . . . . . . . . . 306
High Intensity Discharge (HID)
Lighting . . . . . . . . . . . . . . . . . . . . . 306
LED Lighting . . . . . . . . . . . . . . . . . 307
Fog Lamps . . . . . . . . . . . . . . . . . . . 307
Back-Up Lamps . . . . . . . . . . . . . . 307
License Plate Lamp . . . . . . . . . . 308 Electrical System Electrical System Overload . . . 309
Fuses and Circuit Breakers . . . 309
Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 310
Instrument Panel Fuse
Block (Left) . . . . . . . . . . . . . . . . . 314
Instrument Panel Fuse Block
(Right) . . . . . . . . . . . . . . . . . . . . . . 317
Rear Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 319
Wheels and Tires Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 320
All-Season Tires . . . . . . . . . . . . . . 321
Winter Tires . . . . . . . . . . . . . . . . . . 321
Low-Profile Tires . . . . . . . . . . . . . 322
All-Terrain Tires . . . . . . . . . . . . . . . 322
Tire Sidewall Labeling . . . . . . . . 322
Tire Designations . . . . . . . . . . . . . 324
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . 324
Tire Pressure . . . . . . . . . . . . . . . . . 327
Tire Pressure for High-Speed
Operation . . . . . . . . . . . . . . . . . . . 328
Tire Pressure Monitor
System . . . . . . . . . . . . . . . . . . . . . . 329
Tire Pressure Monitor
Operation . . . . . . . . . . . . . . . . . . . 330
Tire Inspection . . . . . . . . . . . . . . . . 333
Tire Rotation . . . . . . . . . . . . . . . . . 334

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 277When It Is Time for New
Tires . . . . . . . . . . . . . . . . . . . . . . . . 335
Buying New Tires . . . . . . . . . . . . . 335
Different Size Tires and
Wheels . . . . . . . . . . . . . . . . . . . . . . 337
Uniform Tire Quality
Grading . . . . . . . . . . . . . . . . . . . . . 337
Wheel Alignment and Tire
Balance . . . . . . . . . . . . . . . . . . . . . 339
Wheel Replacement . . . . . . . . . . 339
Tire Chains . . . . . . . . . . . . . . . . . . . 340
If a Tire Goes Flat . . . . . . . . . . . . 341
Tire Changing . . . . . . . . . . . . . . . . 342
Full-Size Spare Tire . . . . . . . . . . 350
Jump Starting Jump Starting - North
America . . . . . . . . . . . . . . . . . . . . . 351
Towing the Vehicle Towing the Vehicle . . . . . . . . . . . 355
Recreational Vehicle
Towing . . . . . . . . . . . . . . . . . . . . . . 355
Appearance Care Exterior Care . . . . . . . . . . . . . . . . . 360
Interior Care . . . . . . . . . . . . . . . . . . 364
Floor Mats . . . . . . . . . . . . . . . . . . . . 367 General Information For service and parts needs, visit
your dealer. You will receive
genuine GM parts and GM-trained
and supported service people.
Genuine GM parts have one of
these marks:
California Proposition
65 Warning
{ WarningMost motor vehicles, including
this one, as well as many of its
service parts and fluids, contain
and/or emit chemicals known to
the State of California to cause
cancer and birth defects or other
reproductive harm. Engine
exhaust, many parts and
systems, many fluids, and some
component wear by-products
contain and/or emit these
chemicals. For more information
go to www.P65Warnings.ca.gov/
passenger-vehicle.
See Battery - North America 0 298
and Jump Starting - North America
0 351 and the back cover.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
278 Vehicle Care
California Perchlorate
Materials Requirements Certain types of automotive
applications, such as airbag
initiators, seat belt pretensioners,
and lithium batteries contained in
Remote Keyless Entry transmitters,
may contain perchlorate materials.
Special handling may be necessary.
For additional information, see
www.dtsc.ca.gov/hazardouswaste/
perchlorate.
Accessories and
Modifications Adding non-dealer accessories or
making modifications to the vehicle
can affect vehicle performance and
safety, including such things as
airbags, braking, stability, ride and
handling, emissions systems,
aerodynamics, durability, and
electronic systems like antilock
brakes, traction control, and stability
control. These accessories or
modifications could even cause
malfunction or damage not covered
by the vehicle warranty. Damage to suspension components
caused by modifying vehicle height
outside of factory settings will not be
covered by the vehicle warranty.
Damage to vehicle components
resulting from modifications or the
installation or use of non-GM
certified parts, including control
module or software modifications, is
not covered under the terms of the
vehicle warranty and may affect
remaining warranty coverage for
affected parts.
GM Accessories are designed to
complement and function with other
systems on the vehicle. See your
dealer to accessorize the vehicle
using genuine GM Accessories
installed by a dealer technician.
Also, see Adding Equipment to the
Airbag-Equipped Vehicle 0 95 .Vehicle Checks Doing Your Own
Service Work
{ WarningIt can be dangerous to work on
your vehicle if you do not have
the proper knowledge, service
manual, tools, or parts. Always
follow owner ’ s manual procedures
and consult the service manual
for your vehicle before doing any
service work.
If doing some of your own service
work, use the proper service
manual. It tells you much more
about how to service the vehicle
than this manual can. To order the
proper service manual, see Service
Publications Ordering Information
0 395 .
This vehicle has an airbag system.
Before attempting to do your own
service work, see Servicing the
Airbag-Equipped Vehicle 0 95 .

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 279Keep a record with all parts receipts
and list the mileage and the date of
any service work performed. See
Maintenance Records 0 382 .
CautionEven small amounts of
contamination can cause damage
to vehicle systems. Do not allow
contaminants to contact the fluids,
reservoir caps, or dipsticks.
Hood To open the hood:
1. Pull the handle with this symbol
on it. It is inside the vehicle
under the steering wheel. 2. Go to the front of the vehicle to
find the secondary hood
release. The handle is under
the front edge of the hood near
the center. Push the handle to
the right and at the same time
raise the hood.
Before closing the hood, be sure all
the filler caps are on properly. Then
bring the hood from full open to
within 15 cm (6 in) from the closed
position, pause, and push the front
center of the hood with a swift, firm
motion to fully close the hood.