2015 GMC YUKON DENALI engine coolant

Black plate (41,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Instruments and Controls 5-41
ENGINE OIL LOW ADD OIL
On some vehicles, this message
displays when the engine oil level
may be too low. Check the oil level
before filling to the recommended
level. If the oil is not low and this
message remains on, take the
vehicle to your dealer for service.
SeeEngine Oil on page 10-6.
ENGINE OIL HOT IDLE
ENGINE
This message displays when the
engine oil becomes hotter than the
normal operating temperature. Stop
and allow the vehicle to idle until it
cools down. See Engine Coolant
Temperature Gauge on page 5-15.
OIL PRESSURE LOW STOP
ENGINE
This message displays if low oil
pressure levels occur. Stop the
vehicle as soon as safely possible
and do not operate it until the cause
of the low oil pressure has been
corrected. Check the oil as soon as possible and have the vehicle
serviced by your dealer. See
Engine
Oil on page 10-6.
Engine Power Messages
ENGINE POWER IS REDUCED
This message displays and a chime
may sound when the cooling system
temperature gets too hot and the
engine further enters the engine
coolant protection mode. See
Engine Overheating on page 10-16
for more information.
This message also displays when
the vehicle's engine power is
reduced. Reduced engine power
can affect the vehicle's ability to
accelerate. If this message is on,
but there is no reduction in
performance, proceed to your
destination. The performance may
be reduced the next time the vehicle
is driven. The vehicle may be driven
at a reduced speed while this
message is on, but acceleration and
speed may be reduced. Anytime this message stays on, the vehicle
should be taken to your dealer for
service as soon as possible.
Fuel System Messages
FUEL LEVEL LOW
This message displays and a chime
may sound if the fuel level is low.
Refuel as soon as possible. See
Fuel Gauge on page 5-14
andFuel
on page 9-66.
TIGHTEN GAS CAP
This message may display along
with the malfunction indicator lamp
on the instrument cluster if the
vehicle's fuel cap is not tightened
properly. See Malfunction Indicator
Lamp on page 5-20. Reinstall the
fuel cap fully. See Filling the Tank
on page 9-68. The diagnostic
system can determine if the fuel cap
has been left off or improperly
installed. A loose or missing fuel
cap allows fuel to evaporate into the

Black plate (24,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
9-24 Driving and Operating
START/STOP button, for up to a
maximum of 15 seconds. Wait at
least 15 seconds between each
try, to allow the cranking motor
to cool down. When the engine
starts, let go of the button, and
the accelerator. If the vehicle
starts briefly but then stops
again, do the same thing. This
clears the extra gasoline from
the engine. Do not race the
engine immediately after starting
it. Operate the engine and
transmission gently until the oil
warms up and lubricates all
moving parts.
Engine Heater
The engine coolant heater can
provide easier starting and better
fuel economy during engine
warm-up in cold weather conditions
at or below−18°C (0°F). Vehicles
with an engine heater should be
plugged in at least four hours before
starting. There may be an internal
thermostat in the plug end of the cord, which will prevent engine
coolant heater operation at
temperatures above
−18°C (0°F).
To Use the Engine Coolant
Heater
1. Turn off the engine.
2. Open the hood and unwrap the
electrical cord. The cord is by
the left front fender, next to the
engine compartment fuse block.
Check the heater cord for
damage. If it is damaged, do not
use it. See your dealer for a
replacement. Inspect the cord for
damage yearly.
3. Plug the cord into a normal, grounded 110-volt AC outlet.
{Warning
Improper use of the heater cord
or an extension cord can damage
the cord and may result in
overheating and fire.
.Plug the cord into a
three-prong electrical utility
receptacle that is protected
by a ground fault detection
function. An ungrounded
outlet could cause an electric
shock.
.Use a weatherproof,
heavy-duty, 15 amp-rated
extension cord if needed.
Failure to use the
recommended extension cord
in good operating condition,
or using a damaged heater or
extension cord, could make it
(Continued)

Black plate (72,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
9-72 Driving and Operating
Caution (Continued)
The vehicle could be damaged.
Avoid making very sharp turns
while trailering.
When turning with a trailer, make
wider turns than normal. Do this so
the trailer will not strike soft
shoulders, curbs, road signs, trees,
or other objects. Avoid jerky or
sudden maneuvers. Signal well in
advance.
If the trailer turn signal bulbs burn
out, the arrows on the instrument
cluster will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Driving 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 on page 9-34.
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 on
page 10-16.
Parking on Hills
{Warning
Parking 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.

Black plate (1,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-2
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-3
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-5
Engine Oil . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil Life System . . . . . . 10-9
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-10
Engine Air Cleaner/Filter . . . . 10-10
Cooling System . . . . . . . . . . . . 10-12
Engine Coolant . . . . . . . . . . . . . 10-13
Engine Overheating . . . . . . . . 10-16
Engine Fan . . . . . . . . . . . . . . . . . 10-17
Washer Fluid . . . . . . . . . . . . . . . 10-18
Brakes . . . . . . . . . . . . . . . . . . . . . 10-18 Brake Fluid . . . . . . . . . . . . . . . . . 10-19
Battery . . . . . . . . . . . . . . . . . . . . . 10-21
Four-Wheel Drive . . . . . . . . . . . 10-21
Front Axle . . . . . . . . . . . . . . . . . . 10-22
Rear Axle . . . . . . . . . . . . . . . . . . 10-23
Noise Control System . . . . . . 10-23
Starter Switch Check . . . . . . . 10-24
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-25
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-25
Wiper Blade Replacement . . . . . . . . . . . . . . 10-25
Glass Replacement . . . . . . . . 10-26
Windshield Replacement . . . 10-26
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-27
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-27
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . 10-27
LED Lighting . . . . . . . . . . . . . . . 10-27
Fog Lamps . . . . . . . . . . . . . . . . . 10-27
Back-Up Lamps . . . . . . . . . . . . 10-28
License Plate Lamp . . . . . . . . 10-29
Replacement Bulbs . . . . . . . . . 10-30
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-30
Fuses . . . . . . . . . . . . . . . . . . . . . . 10-31
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-31
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . 10-34
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . 10-37
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-40
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-41
All-Season Tires . . . . . . . . . . . . 10-42
Winter Tires . . . . . . . . . . . . . . . . 10-42
Low-Profile Tires . . . . . . . . . . . 10-43
All-Terrain Tires . . . . . . . . . . . . 10-43
Tire Sidewall Labeling . . . . . . 10-43
Tire Designations . . . . . . . . . . . 10-45
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . 10-46
Tire Pressure . . . . . . . . . . . . . . . 10-48
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . 10-50
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-50

Black plate (6,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
10-6 Vehicle Care
1. Positive (+) Terminal. SeeJump
Starting on page 10-74.
2. Battery on page 10-21.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System on page 10-12.
4. Engine Air Cleaner/Filter on
page 10-10.
5. Remote Negative (–) Location (Out of View). See Jump Starting
on page 10-74.
6. Engine Cooling Fans (Out of View). See Cooling System on
page 10-12.
7. Engine Oil Fill Cap. See “When
to Add Engine Oil” underEngine
Oil on page 10-6.
8. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil on page 10-6.
9. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid on
page 10-18. 10. Brake Fluid Reservoir. See
Brake Fluid on page 10-19.
11. Engine Compartment Fuse
Block on page 10-31.
Engine Oil
To ensure proper engine
performance and long life, careful
attention must be paid to engine oil.
Following these simple, but
important steps will help protect
your investment:
.Always use engine oil approved
to the proper specification and of
the proper viscosity grade. See
“Selecting the Right Engine Oil”
in this section.
.Check the engine oil level
regularly and maintain the
proper oil level. See “Checking
Engine Oil” and“When to Add
Engine Oil” in this section.
.Change the engine oil at the
appropriate time. See Engine Oil
Life System on page 10-9.
.Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.
Checking Engine Oil
If equipped, the ENGINE OIL LOW
ADD OIL message displays when
the engine oil level may be too low.
SeeEngine Oil Messages on
page 5-40. Check the oil level
before filling to the recommended
level. If the oil is not low and this
message remains on, see your
dealer.
It is also a good idea to check the
engine oil level at each fuel fill. In
order to get an accurate reading,
the vehicle must be on level ground.
The engine oil dipstick handle is a
loop. See Engine Compartment
Overview on page 10-5 for the
location of the engine oil dipstick.
Obtaining an accurate oil level
reading is essential:
1. If the engine has been running
recently, turn off the engine and
allow several minutes for the oil

Black plate (12,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
10-12 Vehicle Care
Warning (Continued)
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.
{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 you are 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 electric engine cooling fan can
start even when the engine is not
running. To avoid injury, always
keep hands, clothing, and tools
away from any engine
cooling fan.
{Warning
Heater and radiator hoses, and
other engine parts, can be very
hot. Do not touch them. If you do,
you can be burned.
Do not run the engine if there is a
leak. If you run the engine, it
could lose all coolant. That could
cause an engine fire, and you
could be burned. Get any leak
fixed before you drive the vehicle.
{Caution
Using coolant other than
DEX-COOL®can cause
premature engine, heater core,
or radiator corrosion. In addition,
the engine coolant could require
changing sooner. Any repairs
would not be covered by the
(Continued)

Black plate (13,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Vehicle Care 10-13
Caution (Continued)
vehicle warranty. Always use
DEX-COOL (silicate-free) coolant
in 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 on
page 10-16.
What to Use
{Warning
Adding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water
and other liquids, can boil before
the proper coolant mixture will.
The coolant warning system is set
for the proper coolant mixture.
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
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. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. If using this mixture,
nothing else needs to be added.
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
If improper coolant mixture,
inhibitors, or additives are used in
the vehicle cooling system, the
engine could overheat and be
damaged. Too much water in the
(Continued)

Black plate (14,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
10-14 Vehicle Care
Caution (Continued)
mixture can freeze and crack
engine cooling parts. The repairs
would not be covered by the
vehicle warranty. Use only the
proper mixture of engine coolant
for the cooling system. See
Recommended Fluids and
Lubricants on page 11-11.
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 on
page 10-5.
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
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
You can be burned if you spill
coolant on hot engine parts.
Coolant contains ethylene glycol
and it will burn if the engine parts
are hot enough. Do not spill
coolant on a hot engine.