2023 GMC YUKON DENALI coolant temperature

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
Driving and Operating 279
that the cargo and trailer are secure and
that the lamps and any trailer brakes are
working.
Towing with a Stability Control System
When towing, the stability control system
might be heard. The system reacts to
vehicle movement caused by the trailer,
which mainly occurs during cornering. This is
normal when towing heavier trailers.
Following Distance
Stay at least twice as far behind the vehicle
ahead as you would when driving without a
trailer. This can help to avoid heavy braking
and sudden turns.
Passing
More passing distance is needed when
towing a trailer. The combination of the
vehicle and trailer will not accelerate as
quickly and is much longer than the vehicle
alone. It is necessary to go much farther
beyond the passed vehicle before returning
to the lane. Pass on level roadways. Avoid
passing on hills if possible.
Backing Up
Hold the bottom of the steering wheel with
one hand. To move the trailer to the left,
move that hand to the left. To move the
trailer to the right, move that hand to the
right. Always back up slowly and, if possible,
have someone guide you.
Making TurnsCaution
Turn more slowly and make wider arcs
when towing a trailer to prevent damage
to your vehicle. Making very sharp turns
could cause the trailer to contact the
vehicle.
Make wider turns than normal when towing,
so trailer will not go over soft shoulders,
over curbs, or strike road signs, trees,
or other objects. Always signal turns well in
advance. Do not steer or brake suddenly.
Driving on Grades
Reduce speed and shift to a lower gear
before starting down a long or steep
downhill grade. If the transmission is not
shifted down, the brakes may overheat and
result in reduced braking efficiency. The vehicle 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 at higher altitudes, engine
coolant will boil at a lower temperature
than at lower altitudes. If the engine is
turned off immediately after towing at high
altitude on steep uphill grades, the vehicle
could show signs similar to engine
overheating. To avoid this, let the engine
run, 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 0321.
Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and trailer on a
level surface when possible.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 4/26/22
318 Vehicle Care
To inspect or replace the engine air cleaner/
filter:
5.3L V8 Engine Shown, 6.2L V8 Engine Similar1. Remove the three screws, tilt the cover, and slide it out of the assembly.
{Warning
If part replacement is necessary, the part
must be replaced with one of the same
part number or with an equivalent part.
Use of a replacement part without the
same fit, form, and function may result
in personal injury or damage to the
vehicle. 2. Inspect or replace the engine air cleaner/
filter.
3. Lower the cover, slide it into the assembly, then secure with the three
screws.
4. If equipped, reset the engine air filter life system after replacing the engine air
filter. See Engine Air Filter Life System
0 317.
{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
If the vehicle has the Duramax diesel
engine, see the Duramax diesel supplement.
The cooling system allows the engine to
maintain the correct working temperature.
5.3L V8 Engine
1. Engine Electric Cooling Fans (Out
of View)
2. Coolant Surge Tank and Pressure Cap

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 4/26/22
Vehicle Care 319
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 0321.
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-16417394) - 2023 - CRC - 4/26/22
Vehicle Care 321
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 0109 and
Engine Coolant Temperature Warning Light
0 118.
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-16417394) - 2023 - CRC - 4/26/22
322 Vehicle Care
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 Towing0281.
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./
Canada/Mexico-16417394) - 2023 - CRC - 4/26/22
Vehicle Care 323
Engine Fan
If the vehicle has electric cooling fans, the
fans may be heard spinning at low speed
during most everyday driving. The fans may
turn off if no cooling is required. Under
heavy vehicle loading, trailer towing, high
outside temperatures, or operation of the air
conditioning system, the fans may change
to high speed and an increase in fan noise
may be heard. This is normal and indicates
that the cooling system is functioning
properly. The fans will change to low speed
when additional cooling is no longer
required.
The electric engine cooling fans may run
after the engine has been turned. off. This is
normal and no service is required.
Washer Fluid
What to Use
When windshield washer fluid needs to be
added, be sure to read the manufacturer's
instructions before use. Use a fluid that has
sufficient protection against freezing in an
area where the temperature may fall below
freezing.
Adding Washer Fluid
The vehicle has a low washer fluid message
on the DIC that comes on when the washer
fluid is low. The message is displayed for
15 seconds at the start of each ignition cycle.
When the WASHER FLUID LOW ADD FLUID
message displays, washer fluid will need to
be added to the windshield washer fluid
reservoir.
Open the cap with the washer symbol on it.
Add washer fluid until the tank is full. See
Engine Compartment Overview0311 for
reservoir location.
Caution
.Do not use washer fluid that contains
any type of water repellent coating.
This can cause the wiper blades to
chatter or skip.
(Continued)
Caution (Continued)
.Do not use engine coolant (antifreeze)
in the windshield washer. It can
damage the windshield washer system
and paint.
.Do not mix water with ready-to-use
washer fluid. Water can cause the
solution to freeze and damage the
washer fluid tank and other parts of
the washer system.
.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 linings have built-in wear
indicators that make a high-pitched warning
sound when the brake linings are worn and
new linings 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-16417394) - 2023 - CRC - 5/11/22
Index 421
Child Restraints (cont'd)Lower Anchors and Tethers for
Children . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Older Children . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Securing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85, 87
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Child Safety Locks . . . . . . . . . . . . . . . . . . . . . . . . . 17
Circuit Breakers . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Cleaning
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 378
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 382
Climate Control Systems
Dual Automatic . . . . . . . . . . . . . . . . . . . . . . . . . 175
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Cluster, Instrument . . . . . . . . . . . . . . . . . . . . . . 105
Collision Damage Repair . . . . . . . . . . . . . . . . . 405
Compartments Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Compass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Connected Services Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . 416
Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 418
Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416
Connections Connected Services . . . . . . . . . . . . . . . . . . . . 416
Control Hill Descent . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 Control (cont'd)
Traction and Electronic Stability . . . . . . . 214
Control Light Hill Descent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Control of a Vehicle . . . . . . . . . . . . . . . . . . . . . .185
Controls Steering Wheel . . . . . . . . . . . . . . . . . . . . . . . . 143
Convenience Net . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Convex Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Coolant Engine Temperature Gauge . . . . . . . . . . . . 109
Engine Temperature Warning Light . . . . . 118
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175, 178
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . .318
Courtesy Transportation Program . . . . . . . . 404
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 Adaptive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Super . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
Cupholders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Customer Assistance Offices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401
Text Telephone (TTY) Users . . . . . . . . . . . . 401
Customer Information Publications Ordering Information . . . . . 407
Customer Satisfaction Procedure . . . . . . . . . 399
Cybersecurity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409D
Damage Repair, Collision . . . . . . . . . . . . . . . . . 405
Danger, Warning, and Caution . . . . . . . . . . . . . .2
Dashboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Data Collection
Infotainment System . . . . . . . . . . . . . . . . . . 410
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 410
Data Recorders, Event . . . . . . . . . . . . . . . . . . . 409
Daytime Running Lamps (DRL) . . . . . . . . . . . . 135
Defensive Driving . . . . . . . . . . . . . . . . . . . . . . . . .185
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Destination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .158
Diagnostics Connected Services . . . . . . . . . . . . . . . . . . . . 418
Disabled Vehicle Transporting . . . . . . . . . . . . . . . . . . . . . . . . . . . 373
Distracted Driving . . . . . . . . . . . . . . . . . . . . . . . . 184
Dome Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .138
Door Ajar Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . 16
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Power Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Drive Belt Routing, Engine . . . . . . . . . . . . . . . 398
Drive Systems
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 326
Driver Assistance Systems . . . . . . . . . . . . . . . . . . . . 249

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-16417394) - 2023 - CRC - 5/11/22
422 Index
Driver (cont'd)Information Center (DIC) . . . . . . . . . . . . . . . 123
Mode Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Mode Control Light . . . . . . . . . . . . . . . . . . . . . 119
Teen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
Driving Assistance Systems . . . . . . . . . . . . . . . . . . . . 264
Better Fuel Economy . . . . . . . . . . . . . . . . . . . 184
Characteristics and Towing Tips . . . . . . . . 277
Defensive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Distracted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
Hill and Mountain Roads . . . . . . . . . . . . . . . 191
If the Vehicle is Stuck . . . . . . . . . . . . . . . . . 193
Impaired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Loss of Control . . . . . . . . . . . . . . . . . . . . . . . . 187
Off-Road . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
Off-Road Recovery . . . . . . . . . . . . . . . . . . . . . 186
Vehicle Load Limits . . . . . . . . . . . . . . . . . . . . 194
Wet Roads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
Dual
Automatic Climate Control System . . . . . 175
Dynamic Fuel Management . . . . . . . . . . . . . . 203
E
Electric Brake Boost . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
Parking Brake . . . . . . . . . . . . . . . . . . . . . . . . . . 212 Electric (cont'd)
Parking Brake Light . . . . . . . . . . . . . . . . . . . . . 115
Electrical Equipment, Add-On . . . . . . . . . . . . . . . . . . . . 305
System Overload . . . . . . . . . . . . . . . . . . . . . . 330
Electrical System Engine Compartment Fuse Block . . . . . . . 332
Fuses and Circuit Breakers . . . . . . . . . . . . . 332
Instrument Panel Fuse Block . . . . . . . . . . . 336
Rear Compartment Fuse Block . . . . . . . . . 338
Emergency OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . . 317
Air Filter Life System . . . . . . . . . . . . . . . . . . . 317
Check Light (Malfunction Indicator) . . . . . 113
Compartment Overview . . . . . . . . . . . . . . . . . 311
Coolant Temperature Gauge . . . . . . . . . . . 109
Coolant Temperature Warning Light . . . . 118
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 318
Drive Belt Routing . . . . . . . . . . . . . . . . . . . . . 398
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . 316
Oil Pressure Gauge . . . . . . . . . . . . . . . . . . . . 109
Oil Pressure Light . . . . . . . . . . . . . . . . . . . . . . . 121
Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
Power Messages . . . . . . . . . . . . . . . . . . . . . . . 129 Engine (cont'd)
Running While Parked . . . . . . . . . . . . . . . . . 204
Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
Entry Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Equipment, Towing . . . . . . . . . . . . . . . . . . . . . . 285
Event Data Recorders . . . . . . . . . . . . . . . . . . . . 409
Exit Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Extended Parking . . . . . . . . . . . . . . . . . . . . . . . . 203
Extender, Seat Belt . . . . . . . . . . . . . . . . . . . . . . . 60
Exterior Lamp Controls . . . . . . . . . . . . . . . . . . . . . . . . . 133
Lamps Off Reminder . . . . . . . . . . . . . . . . . . . 134
Lighting Battery Saver . . . . . . . . . . . . . . . . . 140
F
FanEngine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Filter Engine Air Cleaner . . . . . . . . . . . . . . . . . . . . . . 317
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Flashers, Hazard Warning . . . . . . . . . . . . . . . . 136
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359 Changing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360
Floor Console Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385
Fluid
Automatic Transmission . . . . . . . . . . . . . . . 316