
GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-12460267) - 2019 - crc - 9/11/18
310 Vehicle Care
{Warning
Operating the engine with the air
cleaner/filter off can cause you or
others to be burned. Use caution
when working on the engine. Do
not start the engine or drive the
vehicle with the air cleaner/filter
off, as flames may be present if
the engine backfires.
Caution
If 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 TankPressure 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.
{Warning
Do 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 0313.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-12460267) - 2019 - crc - 9/11/18
Vehicle Care 311
What to Use
{Warning
Plain water, or other liquids such
as alcohol, can boil before the
proper coolant mixture will. With
plain water or the wrong mixture,
the engine could get too hot but
there would not be an overheat
warning. The engine could catch
fire and you or others could be
burned.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. This mixture:
. Gives freezing protection down
to−37 °C (−34 °F), outside
temperature
. Gives boiling protection up to
129 °C (265 °F), engine
temperature
. Protects against rust and
corrosion
. Will not damage aluminum parts .
Helps keep the proper engine
temperatureCaution
Do not use anything other than a
mix of DEX-COOL coolant that
meets GM Standard
GMW3420 and clean, drinkable
water. Anything else can cause
damage to the engine cooling
system and the vehicle, which
would not be covered by the
vehicle warranty.
Never dispose of engine coolant by
putting it in the trash, or by pouring
it on the ground, or into sewers,
streams, or bodies of water. Have
the coolant changed by an
authorized service center, familiar
with legal requirements regarding
used coolant disposal. This will help
protect the environment and your
health.
Checking Coolant
The coolant surge tank is in the
engine compartment on the
passenger side of the vehicle. See
Engine Compartment Overview
0 299.
The vehicle must be on a level
surface when checking the coolant
level.
Check to see if coolant is visible in
the coolant surge tank. If the coolant
inside the coolant surge tank is
boiling, wait until it cools down. The
coolant level should be at or above

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-12460267) - 2019 - crc - 9/11/18
312 Vehicle Care
the full cold mark. If it is not, there
may be a leak in the cooling
system.
If coolant is visible but the coolant
level is not at or above the full cold
mark, see“How to Add Coolant to
the Coolant Surge Tank,” following.
How to Add Coolant to the
Coolant Surge Tank
{Warning
Spilling coolant on hot engine
parts can burn you. Coolant
contains ethylene glycol and it will
burn if the engine parts are hot
enough.
{Warning
Plain water, or other liquids such
as alcohol, can boil before the
proper coolant mixture will. With
plain water or the wrong mixture,
the engine could get too hot but
(Continued)
Warning (Continued)
there would not be an overheat
warning. The engine could catch
fire and you or others could be
burned.
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure
cap, even a little, can cause them
to come out at high speed and
you could be burned. Never turn
the cap when the cooling system,
including the pressure cap, is hot.
Wait for the cooling system and
pressure cap to cool.
Caution
Failure to follow the specific
coolant fill procedure could cause
the engine to overheat and could
cause system damage. If coolant
is not visible in the surge tank,
contact your dealer.
If no coolant is visible in the surge
tank, add coolant.
1. Remove the coolant surge tank pressure cap when the cooling
system, including the coolant
surge tank pressure cap and
upper radiator hose, is no
longer hot.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-12460267) - 2019 - crc - 9/11/18
Vehicle Care 313
Turn the pressure cap slowly
counterclockwise about one full
turn. If a hiss is heard, wait for
that to stop. A hiss means
there is still some pressure left.
2. Keep turning the pressure cap slowly, and remove it.
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.
Caution
If 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
Caution
Do 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 0148.
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
0 415.
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-12460267) - 2019 - crc - 9/11/18
314 Vehicle Care
If Steam is Coming from the
Engine Compartment
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure
cap, even a little, can cause them
to come out at high speed and
you could be burned. Never turn
the cap when the cooling system,
including the pressure cap, is hot.
Wait for the cooling system and
pressure cap to cool.
If No Steam is Coming from
the Engine Compartment
The ENGINE OVERHEATED STOP
ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message, along with a low coolant
condition, can indicate a serious
problem.If there is an engine overheat
warning, but no steam is seen or
heard, the problem may not be too
serious. Sometimes the engine can
get a little too hot when the vehicle:
.
Climbs a long hill on a hot day.
. Stops after high-speed driving.
. Idles for long periods in traffic.
. Tows a trailer; see Trailer Towing
0 278.
If the ENGINE OVERHEATED
STOP ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message appears with no sign of
steam, try this for a minute or so: 1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the
highest fan speed. Open the
windows as necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or
N (Neutral), and let the
engine idle. If the engine coolant temperature
gauge is no longer in the overheat
zone or an overheat warning no
longer displays, the vehicle can be
driven. Continue to drive the vehicle
slowly for about 10 minutes. Keep a
safe vehicle distance from the
vehicle in front. If the warning does
not come back on, continue to drive
normally and have the cooling
system checked for proper fill and
function.
If the warning continues, pull over,
stop, and park the vehicle
right away.
If there is still no sign of steam and
the vehicle is equipped with an
engine driven cooling fan, push
down the accelerator until the
engine speed is about twice as fast
as normal idle speed for at least
five minutes while the vehicle is
parked. If the warning is still there,
turn off the engine and get everyone
out of the vehicle until it cools down.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-12460267) - 2019 - crc - 9/11/18
440 Index
Driver InformationCenter (DIC) . . . . . . . . . . . . . . . . . . 161
Driving Assistance Systems . . . . . . . . . . 260
Characteristics andTowing Tips . . . . . . . . . . . . . . . . . 273
Defensive . . . . . . . . . . . . . . . . . . . . . 201
Drunk . . . . . . . . . . . . . . . . . . . . . . . . . 201
For Better Fuel Economy . . . . . . . 27
Hill and Mountain Roads . . . . . . 209
If the Vehicle is Stuck . . . . . . . . . .211
Loss of Control . . . . . . . . . . . . . . . 203
Off-Road . . . . . . . . . . . . . . . . . . . . . 203
Off-Road Recovery . . . . . . . . . . . 202
Vehicle Load Limits . . . . . . . . . . . 212
Wet Roads . . . . . . . . . . . . . . . . . . . 208
Winter . . . . . . . . . . . . . . . . . . . . . . . . 209
Dual Automatic Climate Control System . . . . . . . . . . . . . . . . 191
E
E85 or FlexFuel . . . . . . . . . . . . . . . . 270
Electrical Equipment,Add-On . . . . . . . . . . . . . . . . . . . . . . . 294
Electrical System Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 330
Fuses and Circuit Breakers . . . 329 Electrical System (cont'd)
Instrument Panel Fuse
Block . . . . . . . . . . . . . . . . . . . 334, 337
Overload . . . . . . . . . . . . . . . . . . . . . 329
Rear Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 339
Emergency OnStar . . . . . . . . . . . . . . . . . . . . . . . 426
Engine
Air Cleaner/Filter . . . . . . . . . . . . . 309
Check Light (MalfunctionIndicator) . . . . . . . . . . . . . . . . . . . . 153
Compartment Overview . . . . . . . 299
Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . 148
Coolant Temperature Warning Light . . . . . . . . . . . . . . . 158
Cooling System . . . . . . . . . . . . . . . 310
Drive Belt Routing . . . . . . . . . . . . 410
Exhaust . . . . . . . . . . . . . . . . . . . . . . 227
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Heater . . . . . . . . . . . . . . . . . . . . . . . . 223
Oil Life System . . . . . . . . . . . . . . . 304
Oil Pressure Gauge . . . . . . . . . . 147
Oil Pressure Light . . . . . . . . . . . . 159
Overheating . . . . . . . . . . . . . . . . . . 313
Power Messages . . . . . . . . . . . . . 168
Running While Parked . . . . . . . . 228 Engine (cont'd)
Starting . . . . . . . . . . . . . . . . . . . . . . . 221
Entry Lighting . . . . . . . . . . . . . . . . . . . 188
Equipment, Towing . . . . . . . . . . . . . 284
Event Data Recorders . . . . . . . . . . 423
Exit Lighting . . . . . . . . . . . . . . . . . . . . 188
Extended Parking . . . . . . . . . . . . . . . 226
Extender, Seat Belt . . . . . . . . . . . . . . 90
Exterior Lamp Controls . . . . . . . . . 181
Exterior Lamps Off Reminder . . . 183
Exterior Lighting Battery Saver . . . . . . . . . . . . . . . . . . . . . . . . . 189
F
FanEngine . . . . . . . . . . . . . . . . . . . . . . . . 315
Features Memory . . . . . . . . . . . . . . . . . . . . . . . . . 12
Filter,
Engine Air Cleaner . . . . . . . . . . . 309
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 184
Flashers, Hazard Warning . . . . . . 185
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . 362 Changing . . . . . . . . . . . . . . . . . . . . . 363
FlexFuel E85 . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Floor Console Storage . . . . . . . . . . 129
Floor Mats . . . . . . . . . . . . . . . . . . . . . . 391

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-12460267) - 2019 - crc - 9/11/18
444 Index
Mirrors (cont'd)Manual Rearview . . . . . . . . . . . . . . . 60
Power . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Tilt in Reverse . . . . . . . . . . . . . . . . . . 59
Mirrors, Interior Rearview . . . . . . . . 60
Monitor System, Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 349
N
NavigationConnected Services . . . . . . . . . . 433
Net, Convenience . . . . . . . . . . . . . . 129
New Vehicle Break-In . . . . . . . . . . . 216
Noise Control System . . . . . . . . . . 320
O
Odometer . . . . . . . . . . . . . . . . . . . . . . . 146 Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Off-Road . . . . . . . . . . . . . . . . . . . . . . . 203 Driving . . . . . . . . . . . . . . . . . . . . . . . . 203
Recovery . . . . . . . . . . . . . . . . . . . . . 202
Oil Engine . . . . . . . . . . . . . . . . . . . . . . . . 302
Engine Oil Life System . . . . . . . 304
Engine Oil Pressure Gauge . . . 147
Pressure Light . . . . . . . . . . . . . . . . 159
Older Children, Restraints . . . . . . 104
Online Owner Center . . . . . . . . . . . 414
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . 424 OnStar Additional
Information . . . . . . . . . . . . . . . . . . . . 427
OnStar Emergency . . . . . . . . . . . . . 426
OnStar Overview . . . . . . . . . . . . . . . 425
OnStar Security . . . . . . . . . . . . . . . . 427
Operation Fog Lamps . . . . . . . . . . . . . . . . . . . 186
Outlets Power . . . . . . . . . . . . . . . . . . . . . . . . 137
Overheating, Engine . . . . . . . . . . . . 313
P
Park Shifting Into . . . . . . . . . . . . . . . . . . . 224
Shifting Out of . . . . . . . . . . . . . . . . 226
Park Assist . . . . . . . . . . . . . . . . . . . . . 256
Parking Brake . . . . . . . . . . . . . . . . . . . . . . . . . 240
Brake and P (Park)Mechanism Check . . . . . . . . . . 322
Extended . . . . . . . . . . . . . . . . . . . . . 226
Over Things That Burn . . . . . . . 226
Parking or Backing Assistance Systems . . . . . . . . . . 256
Passenger Airbag Status Indicator . . . . . . . . . . . . . . . . . . . . . . 152
Passenger Compartment Air Filter . . . . . . . . . . . . . . . . . . . . . . . . . . 197 Passenger Sensing System . . . . . 98
Perchlorate Materials
Requirements, California . . . . . . 297
Personalization Vehicle . . . . . . . . . . . . . . . . . . . . . . . 169
Power Door Locks . . . . . . . . . . . . . . . . . . . . . 45
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Outlets . . . . . . . . . . . . . . . . . . . . . . . 137
Protection, Battery . . . . . . . . . . . . 189
Retained Accessory (RAP) . . . 224
Seat Adjustment . . . . . . . . . . . . . . . . 67
Windows . . . . . . . . . . . . . . . . . . . . . . . 61
Power Assist Steps . . . . . . . . . . . . . . 52
Pregnancy, Using Seat Belts . . . . 88
Privacy Vehicle Data Recording . . . . . . . 423
Program Courtesy Transportation . . . . . . 417
Prohibited Fuels . . . . . . . . . . . . . . . . 269
Proposition 65 Warning,
California . . . . . . . . . . . .296, 318, 374, Back Cover
Publication Ordering
Information . . . . . . . . . . . . . . . . . . . . 420