Page 355 of 490

Black plate (17,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
Vehicle Care 10-17
Warning (Continued)
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 as follows:
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 withthe 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
upper radiator hose can be felt
getting hot. Watch out for the
engine cooling fan.
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.
Page 356 of 490

Black plate (18,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
10-18 Vehicle Care
6. Verify coolant level after engineis shut off and the coolant is
cold. If necessary, repeat coolant
fill procedure Steps 1–6.
Notice: 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
The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge on your vehicle's instrument
panel. See Engine Coolant
Temperature Gauge on page 5-14.
In addition, ENGINE OVERHEATED
STOP ENGINE, ENGINE
OVERHEATED IDLE ENGINE, and
an ENGINE POWER IS REDUCED
message comes on in the Driver
Information Center (DIC) on the
instrument panel. See Engine
Cooling System Messages on
page 5-36 andEngine Power
Messages on page 5-37. If the decision is made not to lift the
hood when this warning appears,
but instead get service help right
away. See
Roadside Assistance
Program on page 13-5.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
Then check to see if the engine
cooling fans are running. If the
engine is overheating, both fans
should be running. If they are not,
do not continue to run the engine
and have the vehicle serviced.
Notice: Running the engine
without coolant may cause
damage or a fire. Vehicle damage
would not be covered by the
warranty. See Overheated Engine
Protection Operating Mode on
page 10-19 for information on
driving to a safe place in an
emergency.
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. 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
vehicles 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.
(Continued)
Page 358 of 490

Black plate (20,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
10-20 Vehicle Care
distances and/or towing a trailer in
the overheat protection mode
should be avoided.
Notice:After driving in the
overheated engine protection
operating mode, to avoid engine
damage, allow the engine to cool
before attempting any repair. The
engine oil will be severely
degraded. Repair the cause of
coolant loss, change the oil and
reset the oil life system. See
Engine Oil on page 10-6.
Engine Fan
The vehicle electric cooling 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.
Power Steering Fluid
See
Engine Compartment Overview
on page 10-5 for reservoir location.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless
there is a leak suspected in the
system or an unusual noise is
heard. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired.
How to Check Power Steering
Fluid
To check the power steering fluid:
1. Turn the key off and let the
engine compartment cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the fluid level on the dipstick.
The level should be at the FULL
COLD mark. If necessary, add only
enough fluid to bring the level up to
the mark.
What to Use
To determine what kind of fluid to
use, see Recommended Fluids and
Lubricants on page 11-12. Always
use the proper fluid.
Page 433 of 490

Black plate (3,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
Service and Maintenance 11-3
for more than a year. The engine oil
and filter must be changed at least
once a year and the oil life system
must be reset. Your trained dealer
technician can perform this work.
If the engine oil life system is reset
accidentally, service the vehicle
within 5 000 km/3,000 mi since the
last service. Reset the oil life
system when the oil is changed.
SeeEngine Oil Life System on
page 10-9.
Tire Rotation and Required
Services Every 12 000 km/
7,500 mi
Rotate the tires, if recommended for
the vehicle, and perform the
following services. See Tire
Rotation on page 10-54.
.Check engine oil level and oil
life percentage. If needed,
change engine oil and filter, and
reset oil life system. See Engine
Oil on page 10-6 andEngine Oil
Life System on page 10-9.
.Check engine coolant level. See
Engine Coolant on page 10-15.
.Check windshield washer fluid
level. See Washer Fluid on
page 10-21.
.Visually inspect windshield wiper
blades for wear, cracking,
or contamination. See Exterior
Care on page 10-86. Replace
worn or damaged wiper blades.
See Wiper Blade Replacement
on page 10-28.
.Check tire inflation pressures.
See Tire Pressure on
page 10-48.
.Inspect tire wear. See Tire
Inspection on page 10-53.
.Visually check for fluid leaks.
.Inspect engine air cleaner filter.
See Engine Air Cleaner/Filter on
page 10-13.
.Inspect brake system.
.Visually inspect steering,
suspension, and chassis
components for damaged, loose, or missing parts or signs of
wear. See
Exterior Care on
page 10-86.
.Check restraint system
components. See Safety System
Check on page 3-25.
.Visually inspect fuel system for
damage or leaks.
.Visually inspect exhaust system
and nearby heat shields for
loose or damaged parts.
.Lubricate body components. See
Exterior Care on page 10-86.
.Check starter switch. See Starter
Switch Check on page 10-27.
.Check automatic transmission
shift lock control function. See
Automatic Transmission Shift
Lock Control Function Check on
page 10-27.
.Check ignition transmission lock.
See Ignition Transmission Lock
Check on page 10-27.