engine overheat GMC YUKON 2021 User Guide

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Vehicle Care 317
factors which include engine revolutions,
engine temperature, and miles driven. Based
on driving conditions, the mileage at which
an oil change is indicated can vary
considerably. For the oil life system to work
properly, the system must be reset every
time the oil is changed.
On some vehicles, when the system has
calculated that oil life has been diminished,
a CHANGE ENGINE OIL SOON message comes
on to indicate that an oil change is
necessary. Change the oil as soon as
possible within the next 1 000 km (600 mi).
It is possible that, if driving under the best
conditions, the oil life system might indicate
that an oil change is not necessary for up to
a year. The engine oil and filter must be
changed at least once a year and, at this
time, the system must be reset. For vehicles
without the CHANGE ENGINE OIL SOON
message, an oil change is needed when the
REMAINING OIL LIFE percentage is near 0%.
Your dealer has trained service people who
will perform this work and reset the system.
It is also important to check the oil regularly
over the course of an oil drain interval and
keep it at the proper level.If the system is ever reset accidentally, the
oil must be changed at 5 000 km (3,000 mi)
since the last oil change. Remember to reset
the oil life system whenever the oil is
changed.
How to Reset the Engine Oil Life System
Reset the system whenever the engine oil is
changed so that the system can calculate
the next engine oil change. Always reset the
engine oil life to 100% after every oil
change. It will not reset itself. To reset the
engine oil life system:
1. Display the oil life percentage on the DIC. See Driver Information Center (DIC)
0 120.
2. Press the thumbwheel on the steering wheel, or the trip odometer reset stem if
the vehicle does not have DIC controls,
for several seconds. When the
confirmation message displays, select
YES. The oil life will change to 100%.
The oil life system can also be reset as
follows: 1. Display the oil life percentage on the DIC. See Driver Information Center (DIC)
0 120.
2. Fully press the accelerator pedal slowly three times within five seconds. 3. If the display changes to 100%, the
system is reset.
If the vehicle has a CHANGE ENGINE OIL
SOON message and it comes back on when
the vehicle is started and/or the oil
life percentage is near 0%, the engine oil
life system has not been reset. Repeat the
procedure.
Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the
transmission fluid level. The only reason for
fluid loss is a transmission leak or
overheated transmission. This vehicle is not
equipped with a transmission fluid level
dipstick. There is a special procedure for
checking and changing the transmission fluid
in these vehicles. Because this procedure is
difficult, this should be done at the dealer.
Contact the dealer for additional information
or the procedure can be found in the service
manual. See Publication Ordering
Information 0406.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
320 Vehicle Care
6.2L V8 Engine
1. Engine Electric Cooling Fans (Outof View)
2. Coolant Surge Tank and Pressure Cap
{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, radiator, a/c pipes
or 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 0322.
What to Use
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain water or
(Continued)
Warning (Continued)
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
temperature.
Caution
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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Vehicle Care 321
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 driver side of the
vehicle. SeeEngine Compartment Overview
0 312.
The vehicle must be on a level surface when
checking the coolant level.
5.3L V8 Engine Shown, 6.2L V8 Engine Similar 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 the indicated 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 indicated mark, see the
following sections on how to add coolant to
the coolant surge tank following.
How to Add Coolant to the Coolant
Surge Tank
If the vehicle has a diesel engine, see
“Cooling System”
in the Duramax diesel
supplement for the proper coolant fill
procedure.
{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 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
322 Vehicle Care
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.
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 indicated 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 and a
engine coolant temperature warning light in
the vehicle's instrument cluster. See Engine
Coolant Temperature Gauge 0108 and
Engine Coolant Temperature Warning Light
0 116.
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
0 402.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Vehicle Care 323
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.
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; seeTrailer Towing0284.
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.
If there is no sign of steam, idle the engine
for five minutes while parked. If the warning
is still displayed, turn off the engine until it
cools down.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-13690468) - 2021 - crc - 8/14/20
Index 421
Driving (cont'd)Defensive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
Hill and Mountain Roads . . . . . . . . . . . . . . 220
If the Vehicle is Stuck . . . . . . . . . . . . . . . . . 221
Impaired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
Loss of Control . . . . . . . . . . . . . . . . . . . . . . . . 216
Off-Road . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
Off-Road Recovery . . . . . . . . . . . . . . . . . . . . . 215
Vehicle Load Limits . . . . . . . . . . . . . . . . . . . . 222
Wet Roads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
Dual Automatic Climate Control
System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Dynamic Fuel Management . . . . . . . . . . . . . . . 231
E
Electric Brake Boost . . . . . . . . . . . . . . . . . . . . . . 240
Electric Parking Brake . . . . . . . . . . . . . . . . . . . . 240
Electric Parking Brake Light . . . . . . . . . . . . . . . 113
Electrical Equipment, Add-On . . . . . . . . . . . . 306
Electrical System Engine Compartment Fuse Block . . . . . . . 332
Fuses and Circuit Breakers . . . . . . . . . . . . . 331
Instrument Panel Fuse Block . . . . . . . . . . . 335
Overload . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
Rear Compartment Fuse Block . . . . . . . . . 337
Electronic Stability Control (ESC) Off Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Emergency
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . 318
Check Light (Malfunction Indicator) . . . . . 111
Compartment Overview . . . . . . . . . . . . . . . . 312
Coolant Temperature Gauge . . . . . . . . . . . 108
Coolant Temperature Warning Light . . . . 116
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 319
Drive Belt Routing . . . . . . . . . . . . . . . . . . . . . 398
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . 316
Oil Pressure Gauge . . . . . . . . . . . . . . . . . . . . 107
Oil Pressure Light . . . . . . . . . . . . . . . . . . . . . . . 118
Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Power Messages . . . . . . . . . . . . . . . . . . . . . . . 125
Running While Parked . . . . . . . . . . . . . . . . . 232
Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
Engine Air Filter Life System . . . . . . . . . . . . . .318
Entry Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Equipment, Towing . . . . . . . . . . . . . . . . . . . . . . 287
Event Data Recorders . . . . . . . . . . . . . . . . . . . . 409
Exit Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Extended Parking . . . . . . . . . . . . . . . . . . . . . . . . . 231
Extender, Seat Belt . . . . . . . . . . . . . . . . . . . . . . . 59
Exterior Lamp Controls . . . . . . . . . . . . . . . . . . . .134
Exterior Lamps Off Reminder . . . . . . . . . . . . 136 Exterior Lighting Battery Saver . . . . . . . . . . . 141
F
Fan
Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Filter, Engine Air Cleaner . . . . . . . . . . . . . . . . . . . . . 318
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Flashers, Hazard Warning . . . . . . . . . . . . . . . . . 137
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355 Changing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Floor Console Storage . . . . . . . . . . . . . . . . . . . . . 92
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .381
Fluid
Automatic Transmission . . . . . . . . . . . . . . . . 317
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
Four-Wheel Drive Transfer Case . . . . . . . . 236
Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Fog Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .138
Folding Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Forward Collision Alert (FCA) System . . . . 267
Four Corner Air Suspension Light . . . . . . . . . 117
Four Corner Air Suspension System . . . . . . 248
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . .236, 327
Four-Wheel-Drive Light . . . . . . . . . . . . . . . . . . . . 114
Frequency Statement Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-13690468) - 2021 - crc - 8/14/20
Index 425
OnStar Additional Information . . . . . . . . . . . . 411
OnStar Emergency . . . . . . . . . . . . . . . . . . . . . . . . 411
OnStar Overview . . . . . . . . . . . . . . . . . . . . . . . . . 410
OnStar Security . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
OnStar System . . . . . . . . . . . . . . . . . . . . . . 155, 174
OperationFog Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Outlets Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Overheating, Engine . . . . . . . . . . . . . . . . . . . . . 322
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .143 Instrument Panel . . . . . . . . . . . . . . . . . . . . . . . . 4
P
ParkShifting Into . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
Shifting Out of . . . . . . . . . . . . . . . . . . . . . . . . 230
Park Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
Parking Brake and P (Park) MechanismCheck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
Extended . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
Over Things That Burn . . . . . . . . . . . . . . . . . 231
Parking or Backing Assistance Systems . . . . . . . . . . . . . . . . . . . . 262
Passenger Airbag Status Indicator . . . . . . . . .110
Passenger Compartment Air Filter . . . . . . . 209
Passenger Sensing System . . . . . . . . . . . . . . . . 66 Pedestrian Ahead Indicator . . . . . . . . . . . . . . . 115
Perchlorate Materials Requirements,
California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309
Personalization Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Phone Apple CarPlay and Android Auto . . . . . . . 186
Bluetooth . . . . . . . . . . . . . . . . . . . . . . . . . . 181, 182
Port USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Positioning
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
Power Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Outlets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Protection, Battery . . . . . . . . . . . . . . . . . . . . . . 141
Retained Accessory (RAP) . . . . . . . . . . . . . . 229
Seat Adjustment . . . . . . . . . . . . . . . . . . . . . . . . 40
Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Power Assist Steps . . . . . . . . . . . . . . . . . . . . . . . . .25
Pregnancy, Using Seat Belts . . . . . . . . . . . . . . 59
Privacy
Vehicle Data Recording . . . . . . . . . . . . . . . . 408
Problems with Route Guidance . . . . . . . . . . . 175
Program
Courtesy Transportation . . . . . . . . . . . . . . . 404
Prohibited Fuels . . . . . . . . . . . . . . . . . . . . . . . . . 277 Proposition 65 Warning,
California . . . . . . . . . . . . . . . . . . . . 309, 327, 367,
Back Cover
Publication Ordering Information . . . . . . . . 406
R
Radio HD Radio Technology . . . . . . . . . . . . . . . . . . 149
Radio Data System (RDS) . . . . . . . . . . . . . . . . 150
Radio Frequency Statement . . . . . . . . . . . . . . 407
Radio Reception . . . . . . . . . . . . . . . . . . . . . . . . . . 151
Radios AM-FM Radio . . . . . . . . . . . . . . . . . . . . . . . . . . 148
Satellite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Reading Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328 Locking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
Rear Camera Mirror . . . . . . . . . . . . . . . . . . . . . . . 30
Rear Climate Control System . . . . . . . . . . . . 207
Rear Pedestrian Alert . . . . . . . . . . . . . . . . . . . . 266
Rear Seat Infotainment (RSI) System . . . . . 156
Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Heated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Rear Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Rear Vision Camera (RVC) . . . . . . . . . . . . . . . . 262
Rear Window Washer/Wiper . . . . . . . . . . . . . 98
Rearview Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 30 Automatic Dimming . . . . . . . . . . . . . . . . . . . . 30