2015 GMC YUKON XL engine coolant

Black plate (76,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
9-76 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 9-36.
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 10-18.
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/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
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 . . . . 10-13
Cooling System . . . . . . . . . . . . 10-14
Engine Coolant . . . . . . . . . . . . . 10-15
Engine Overheating . . . . . . . . 10-18
Engine Fan . . . . . . . . . . . . . . . . . 10-19
Washer Fluid . . . . . . . . . . . . . . . 10-20
Brakes . . . . . . . . . . . . . . . . . . . . . 10-20 Brake Fluid . . . . . . . . . . . . . . . . . 10-21
Battery . . . . . . . . . . . . . . . . . . . . . 10-23
Four-Wheel Drive . . . . . . . . . . . 10-24
Front Axle . . . . . . . . . . . . . . . . . . 10-24
Rear Axle . . . . . . . . . . . . . . . . . . 10-25
Noise Control System . . . . . . 10-26
Starter Switch Check . . . . . . . 10-27
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-27
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-27
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-28
Wiper Blade Replacement . . . . . . . . . . . . . . 10-28
Glass Replacement . . . . . . . . 10-29
Windshield Replacement . . . 10-29
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-29
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-30
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . 10-30
LED Lighting . . . . . . . . . . . . . . . 10-30
Headlamps . . . . . . . . . . . . . . . . . 10-30
Front Turn Signal Lamps . . . 10-30 Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-31
License Plate Lamp . . . . . . . . 10-32
Replacement Bulbs . . . . . . . . . 10-33
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-33
Fuses . . . . . . . . . . . . . . . . . . . . . . 10-33
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-34
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . 10-38
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . 10-40
Rear Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . 10-43
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-44
All-Season Tires . . . . . . . . . . . . 10-45
Winter Tires . . . . . . . . . . . . . . . . 10-45
Low-Profile Tires . . . . . . . . . . . 10-46
All-Terrain Tires . . . . . . . . . . . . 10-46
Tire Sidewall Labeling . . . . . . 10-46
Tire Designations . . . . . . . . . . . 10-48
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . 10-49

Black plate (6,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
10-6 Vehicle Care
1. Positive (+) Terminal. SeeJump
Starting on page 10-78.
2. Battery on page 10-23.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System on page 10-14.
4. Engine Air Cleaner/Filter on
page 10-13.
5. Automatic Transmission Dipstick. See “How to Check
Automatic Transmission Fluid”
under Automatic Transmission
Fluid on page 10-10.
6. Remote Negative (–) Location (Out of View). See Jump Starting
on page 10-78.
7. Engine Cooling Fans (Out of View). See Cooling System on
page 10-14.
8. Engine Oil Fill Cap. See “When
to Add Engine Oil” underEngine
Oil on page 10-6.
9. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil on page 10-6. 10. Windshield Washer Fluid
Reservoir. See “Adding Washer
Fluid” under Washer Fluid on
page 10-20.
11. Brake Fluid Reservoir. See Brake Fluid on page 10-21.
12. Engine Compartment Fuse
Block on page 10-34.
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 5-34. 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.

Black plate (14,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
10-14 Vehicle Care
8. Reverse Steps 2-4 to reinstallthe filter cover housing.
{Warning
Operating 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.
{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 Tank
Pressure 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.

Black plate (15,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
Vehicle Care 10-15
{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
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 10-18.
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 (16,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
10-16 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 11-12.
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.

Black plate (17,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
Vehicle Care 10-17
{Caution
This vehicle has a specific
coolant fill procedure. Failure to
follow this procedure could cause
the engine to overheat and be
severely damaged.
{Warning
Steam and scalding liquids from a
hot cooling system can blow out
and burn you badly. Never turn
the cap when the cooling system,
including the surge tank pressure
cap, is hot. Wait for the cooling
system and surge tank pressure
cap to cool.
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 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.

Black plate (18,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
10-18 Vehicle Care
{Caution
If the pressure cap is not tightly
installed, coolant loss and
possible engine damage may
occur. Be sure the cap is properly
and tightly secured.
Engine Overheating
{Caution
Running the engine without
coolant may cause damage or a
fire. Vehicle damage would not be
covered by the vehicle warranty.
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 on page 5-16. In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC). See
Engine Cooling System Messages
on page 5-33
andEngine Power
Messages on page 5-35.
If the decision is made not to lift the
hood when this warning appears,
get service help right away.
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 and have
the vehicle serviced.
If Steam is Coming from the
Engine Compartment
{Warning
Steam from an overheated engine
can burn you badly, even if you
just open the hood. Stay away
from the engine if you see or hear
steam coming from it. Just turn it
off and get everyone away from
the vehicle until it cools down.
Wait until there is no sign of
steam or coolant before you open
the hood.
If you keep driving when the
engine is overheated, the liquids
in it can catch fire. You or others
could be badly burned. Stop the
engine if it overheats, and get out
of the vehicle until the engine
is cool.