2018 GMC YUKON XL heating

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

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 291
{ WarningOperating the engine with the air
cleaner/filter off can cause you or
others to be burned. The air
cleaner not only cleans the air; it
helps to stop flames if the engine
backfires. Use caution when
working on the engine and do not
drive with the air cleaner/filter off.
CautionIf the air cleaner/filter is off, dirt
can easily get into the engine,
which could damage it. Always
have the air cleaner/filter in place
when driving.
Cooling System The cooling system allows the
engine to maintain the correct
working temperature. 1. Coolant Surge Tank
2. Coolant Surge Tank
Pressure Cap
3. Engine Electric
Cooling Fan(s)
{ Warning
An underhood electric fan can
start up even when the engine is
not running and can cause injury.
Keep hands, clothing, and tools
away from any underhood
electric fan. { WarningDo not touch heater or radiator
hoses, or other engine parts.
They can be very hot and can
burn you. Do not run the engine if
there is a leak; all coolant could
leak out. That could cause an
engine fire and can burn you. Fix
any leak before driving the
vehicle.
Engine Coolant The cooling system in the vehicle is
filled with DEX-COOL engine
coolant. This coolant is designed to
remain in the vehicle for 5 years or
240 000 km (150,000 mi), whichever
occurs first.
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating,
see Engine Overheating 0 294 .

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
294 Vehicle Care 3. Fill the coolant surge tank with
the proper mixture to the full
cold mark.
4. With the coolant surge tank
pressure cap off, start the
engine and let it run until the
engine coolant temperature
gauge indicates approximately
90 °C (195 °F).
By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
lower, add more of the proper
mixture to the coolant surge
tank until the level reaches the
full cold mark.
5. Replace the pressure cap
tightly.
6. Verify coolant level after the
engine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1 – 6. CautionIf the pressure cap is not tightly
installed, coolant loss and engine
damage may occur. Be sure the
cap is properly and tightly
secured.
Engine Overheating CautionDo not run the engine if there is a
leak in the engine cooling system.
This can cause a loss of all
coolant and can damage the
system and vehicle. Have any
leaks fixed right away.
The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge in the vehicle's instrument
cluster. See Engine Coolant
Temperature Gauge 0 138 . In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC).
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance Program
0 390 .
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
Check to see if the engine cooling
fan(s) are running. If the engine is
overheating, the fans should be
running. If they are not, do not
continue to run the engine. Have the
vehicle serviced.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 319Relays Usage
52 Retained accessory
power
Rear Compartment Fuse
Block
The rear compartment fuse block is
behind the access panel on the left
side of the compartment.
Pull the panel out by grabbing the
finger access slot at the rear edge. The vehicle may not be equipped
with all of the fuses, relays, and
features shown. Fuses Usage
1 Rear window
defogger relay
2 –
3 Right heated second
row seat
4 Heated mirrors
5 Liftgate
6 Glass breakage
7 Liftglass
8 Liftgate module logic
9 Rear wiper
10 Rear heating,
ventilation, and air
conditioning blower
11 Second row seat
12 Liftgate module
13 Third row seat
14 Rear accessory power
outlet
15 Rear window
defogger
16 Liftgate

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 327Vehicle Maximum Load on the
Tire :
Load on an individual tire
due to curb weight, accessory
weight, occupant weight, and
cargo weight.
Vehicle Placard :
A label
permanently attached to a
vehicle showing the vehicle
capacity weight and the original
equipment tire size and
recommended inflation pressure.
See “ Tire and Loading
Information Label ” under Vehicle
Load Limits 0 200 .
Tire Pressure Tires need the correct amount of
air pressure to operate
effectively. Caution
Neither tire underinflation nor
overinflation is good.
Underinflated tires, or tires
that do not have enough air,
can result in: .
Tire overloading and
overheating which could
lead to a blowout. .
Premature or
irregular wear. .
Poor handling. .
Reduced fuel economy.
Overinflated tires, or tires that
have too much air, can
result in: .
Unusual wear.
.
Poor handling.
.
Rough ride.
.
Needless damage from
road hazards. The Tire and Loading
Information label on the vehicle
indicates the original equipment
tires and the correct cold tire
inflation pressures. The
recommended pressure is the
minimum air pressure needed to
support the vehicle's maximum
load carrying capacity.
For additional information
regarding how much weight the
vehicle can carry, and an
example of the Tire and Loading
Information label, see Vehicle
Load Limits 0 200 . How the
vehicle is loaded affects vehicle
handling and ride comfort. Never
load the vehicle with more
weight than it was designed to
carry.
When to Check
Check the tires once a month
or more.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Index 415Driving (cont'd)
Defensive . . . . . . . . . . . . . . . . . . . . . 190
Drunk . . . . . . . . . . . . . . . . . . . . . . . . . 190
For Better Fuel Economy . . . . . . . 26
Hill and Mountain Roads . . . . . . 198
If the Vehicle is Stuck . . . . . . . . . 200
Loss of Control . . . . . . . . . . . . . . . 192
Off-Road . . . . . . . . . . . . . . . . . . . . . 192
Off-Road Recovery . . . . . . . . . . . 191
Vehicle Load Limits . . . . . . . . . . . 200
Wet Roads . . . . . . . . . . . . . . . . . . . 197
Winter . . . . . . . . . . . . . . . . . . . . . . . . 198
Dual Automatic Climate
Control System . . . . . . . . . . . . . . . . 180
E E85 or FlexFuel . . . . . . . . . . . . . . . . 256
Electrical Equipment,
Add-On . . . . . . . . . . . . . . . . . . . . . . . 274
Electrical System
Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 310
Fuses and Circuit Breakers . . . 309
Instrument Panel Fuse
Block . . . . . . . . . . . . . . . . . . . 314, 317
Overload . . . . . . . . . . . . . . . . . . . . . 309
Rear Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 319 Emergency
OnStar . . . . . . . . . . . . . . . . . . . . . . . 401
Engine
Air Cleaner/Filter . . . . . . . . . . . . . 290
Check Light (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . 143
Compartment Overview . . . . . . . 280
Coolant Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 138
Coolant Temperature
Warning Light . . . . . . . . . . . . . . . 148
Cooling System . . . . . . . . . . . . . . . 291
Drive Belt Routing . . . . . . . . . . . . 385
Exhaust . . . . . . . . . . . . . . . . . . . . . . 215
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
Heater . . . . . . . . . . . . . . . . . . . . . . . . 210
Oil Life System . . . . . . . . . . . . . . . 285
Oil Pressure Gauge . . . . . . . . . . 137
Oil Pressure Light . . . . . . . . . . . . 149
Overheating . . . . . . . . . . . . . . . . . . 294
Power Messages . . . . . . . . . . . . . 158
Running While Parked . . . . . . . . 215
Starting . . . . . . . . . . . . . . . . . . . . . . . 209
Entry Lighting . . . . . . . . . . . . . . . . . . . 177
Equipment, Towing . . . . . . . . . . . . . 267
Event Data Recorders . . . . . . . . . . 398
Exit Lighting . . . . . . . . . . . . . . . . . . . . 177
Extended Parking . . . . . . . . . . . . . . . 214 Extender, Seat Belt . . . . . . . . . . . . . . 83
Exterior Lamp Controls . . . . . . . . . 170
Exterior Lamps Off Reminder . . . 172
Exterior Lighting Battery
Saver . . . . . . . . . . . . . . . . . . . . . . . . . 178
F Fan
Engine . . . . . . . . . . . . . . . . . . . . . . . . 296
Features
Memory . . . . . . . . . . . . . . . . . . . . . . . . . 12
Filter,
Engine Air Cleaner . . . . . . . . . . . 290
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 172
Flashers, Hazard Warning . . . . . . 174
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . 341
Changing . . . . . . . . . . . . . . . . . . . . . 342
FlexFuel
E85 . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
Floor Mats . . . . . . . . . . . . . . . . . . . . . . 367
Fluid
Automatic
Transmission . . . . . . . . . . . 286, 289
Brakes . . . . . . . . . . . . . . . . . . . . . . . . 297
Four-Wheel Drive
Transfer Case . . . . . . . . . . . . . . . 222
Washer . . . . . . . . . . . . . . . . . . . . . . . 296
Fog Lamps . . . . . . . . . . . . . . . . . . . . . 175
Bulb Replacement . . . . . . . . . . . . 307