
GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
276 Driving and Operating
Trailer Gain Adjustment Procedure
Trailer Gain should be set for a
specific trailering condition and must
be adjusted any time vehicle
loading, trailer loading, or road
surface conditions change.
{Warning
Trailer brakes that are
over-gained or under-gained may
not stop the vehicle and the trailer
as intended and can result in a
crash. Always follow the
instructions to set the Trailer Gain
for the proper trailer stopping
performance.
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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
280 Vehicle Care
Vehicle Care
General Information
General Information . . . . . . . . . . 281
California Proposition65 Warning . . . . . . . . . . . . . . . . . 281
California Perchlorate Materials Requirements . . . . . 282
Accessories and Modifications . . . . . . . . . . . . . . . . 282
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 282
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 283
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 284
Engine Oil . . . . . . . . . . . . . . . . . . . . 287
Engine Oil Life System . . . . . . . 289
Automatic Transmission Fluid (6 Speed Transmission) . . . . . 290
Automatic Transmission Fluid (8 and 10 Speed
Transmission) . . . . . . . . . . . . . . . 293
Engine Air Cleaner/Filter . . . . . . 294
Cooling System . . . . . . . . . . . . . . 295
Engine Overheating . . . . . . . . . . 298
Engine Fan . . . . . . . . . . . . . . . . . . . 300
Washer Fluid . . . . . . . . . . . . . . . . . 300 Brakes . . . . . . . . . . . . . . . . . . . . . . . 301
Brake Fluid . . . . . . . . . . . . . . . . . . . 302
Battery - North America . . . . . . 303
Four-Wheel Drive . . . . . . . . . . . . . 303
Front Axle . . . . . . . . . . . . . . . . . . . . 304
Rear Axle . . . . . . . . . . . . . . . . . . . . 305
Noise Control System . . . . . . . . 305
Starter Switch Check . . . . . . . . . 306
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 307
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 307
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 307
Wiper Blade Replacement . . . . 308
Glass Replacement . . . . . . . . . . 309
Windshield Replacement . . . . . 309
Gas Strut(s) . . . . . . . . . . . . . . . . . . 309
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 310
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 311
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 311
LED Lighting . . . . . . . . . . . . . . . . . . 311
Fog Lamps . . . . . . . . . . . . . . . . . . . 311
Back-Up Lamps . . . . . . . . . . . . . . 311
License Plate Lamp . . . . . . . . . . 312
Electrical System
Electrical System Overload . . . 313
Fuses and Circuit Breakers . . . 313
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 314
Instrument Panel Fuse
Block (Left) . . . . . . . . . . . . . . . . . 318
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . . . 321
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 323
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 324
All-Season Tires . . . . . . . . . . . . . . 325
Winter Tires . . . . . . . . . . . . . . . . . . 325
Low-Profile Tires . . . . . . . . . . . . . 326
All-Terrain Tires . . . . . . . . . . . . . . . 326
Tire Sidewall Labeling . . . . . . . . 326
Tire Designations . . . . . . . . . . . . . 327
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 328
Tire Pressure . . . . . . . . . . . . . . . . . 331
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . 332
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . . . . 333
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . 334
Tire Inspection . . . . . . . . . . . . . . . . 337

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Vehicle Care 281
Tire Rotation . . . . . . . . . . . . . . . . . 338
When It Is Time for NewTires . . . . . . . . . . . . . . . . . . . . . . . . 339
Buying New Tires . . . . . . . . . . . . . 340
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . 341
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . . . 342
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . 343
Wheel Replacement . . . . . . . . . . 343
Tire Chains . . . . . . . . . . . . . . . . . . . 344
If a Tire Goes Flat . . . . . . . . . . . . 345
Tire Changing . . . . . . . . . . . . . . . . 346
Full-Size Spare Tire . . . . . . . . . . 355
Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . 356
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . 360
Recreational VehicleTowing . . . . . . . . . . . . . . . . . . . . . . 360
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . 365
Interior Care . . . . . . . . . . . . . . . . . . 369
Floor Mats . . . . . . . . . . . . . . . . . . . . 373
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
{Warning
Most 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 0303
and Jump Starting - North America
0 356 and the back cover.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Vehicle Care 283
This vehicle has an airbag system.
Before attempting to do your own
service work, seeServicing the
Airbag-Equipped Vehicle 098.
Keep a record with all parts receipts
and list the mileage and the date of
any service work performed. See
Maintenance Records 0387.
Caution
Even 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 tofind 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Vehicle Care 301
Caution (Continued)
.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
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.
Caution
Continuing 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 0389.
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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Vehicle Care 303
Caution
If brake fluid is spilled on the
vehicle's painted surfaces, the
paint finish can be damaged.
Immediately wash off any painted
surface.
Battery - North America
The original equipment battery is
maintenance free. Do not remove
the cap and do not add fluid.
Refer to the replacement number
shown on the original battery label
when a new battery is needed. See
Engine Compartment Overview
0284 for battery location.
{Warning
WARNING: Battery posts,
terminals, and related
accessories contain lead and lead
compounds, chemicals known to
the State of California to cause
(Continued)
Warning (Continued)
cancer and birth defects or other
reproductive harm. Batteries also
contain other chemicals known to
the State of California to cause
cancer.WASH HANDS AFTER
HANDLING. For more information
go to www.P65Warnings.ca.gov/
passenger-vehicle.
See California Proposition
65 Warning 0281 and the back
cover.
Vehicle Storage
{Warning
Batteries have acid that can burn
you and gas that can explode.
You can be badly hurt if you are
not careful. See Jump Starting -
North America 0356 for tips on
working around a battery without
getting hurt. Infrequent Usage: Remove the
black, negative (−) cable from the
battery to keep the battery from
running down.
Extended Storage: Remove the
black, negative (−) cable from the
battery or use a battery trickle
charger.
Four-Wheel Drive
Transfer Case
When to Check Lubricant
Refer to
Maintenance Schedule
0 376 to determine when to check
the lubricant.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Vehicle Care 319
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Fuses Usage
1 –
2 – Fuses Usage
3 –
4 Accessory power outlet 1
5 Retained accessory power
6 APO/BATT
7 Universal garage door opener/Interior
rearview mirror
8 SEO/Retained accessory power
9 –
10 Body control module 3
11 Body control module 5
12 Steering wheel control backlighting
13 –
14 –
15 –
16 Discrete logic ignition sensor

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
320 Vehicle Care
FusesUsage
17 Video processing module
18 Mirror window module
19 Body control module 1
20 Front bolster (if equipped)
21 –
22 –
23 –
24 HVAC/Ignition
25 Instrument cluster/ Ignition sensing
diagnostic module/
Ignition
26 Tilt column/SEO/Tilt column lock 1/SEO
27 Data link connector/ Driver seat module
28 Passive entry/Passive start/HVAC battery
29 Content theft deterrent Fuses
Usage
30 –
31 –
32 –
33 SEO/Automatic level control/Left heated
second row seat
34 Park enable/Electric adjustable pedal (if
equipped)
35 –
36 Miscellaneous/Run crank
37 Heated steering wheel
38 Steering column lock 2 (if equipped)
39 Instrument cluster battery
40 –
41 –
42 Euro trailer (if equipped)
43 Left doors Fuses
Usage
44 Driver power seat
45 –
46 Right heated, cooled, or ventilated seat (if
equipped)
47 Left heated, cooled, or ventilated seat (if
equipped)
48 –
49 –
50 Accessory power outlet 2
51 –
54 –
55 –
56 –
Relays Usage
52 Retained accessory power
53 Run/Crank relay