
Black plate (10,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
9-10 Driving and Operating
{Caution
Do not drive through standing
water if it is deep enough to cover
the wheel hubs, axles, or exhaust
pipe. Deep water can damage the
axle and other vehicle parts.
If the standing water is not too deep,
drive slowly through it. At faster
speeds, water splashes and the
vehicle can stall. When going
through water, the brakes get wet
and it may take longer to stop. See
“Driving on Wet Roads” later in this
section.
After Off-Road Driving
Remove any brush or debris that
has collected on the underbody or
chassis, or under the hood. These
accumulations can be a fire hazard.
After operation in mud or sand,
have the brake linings cleaned and
checked. These substances can
cause glazing and uneven braking.
Check the body structure, steering, suspension, wheels, tires, and
exhaust system for damage and
check the fuel lines and cooling
system for any leakage.
More frequent maintenance service
is required. See the
Maintenance
Schedule on page 11-2.
Driving on Wet Roads
Rain and wet roads can reduce
vehicle traction and affect your
ability to stop and accelerate.
Always drive slower in these types
of driving conditions and avoid
driving through large puddles and
deep-standing or flowing water.
{Warning
Wet brakes can cause crashes.
They might not work as well in a
quick stop and could cause
pulling to one side. You could
lose control of the vehicle.
(Continued)
Warning (Continued)
After driving through a large
puddle of water or a car/vehicle
wash, lightly apply the brake
pedal until the brakes work
normally.
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be
very cautious about trying to drive
through flowing water.
Hydroplaning
Hydroplaning is dangerous. Water
can build up under the vehicle's
tires so they actually ride on the
water. This can happen if the road is
wet enough and you are going fast
enough. When the vehicle is
hydroplaning, it has little or no
contact with the road.

Black plate (70,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
9-70 Driving and Operating
Fuel
Use of the recommended fuel is an
important part of the proper
maintenance of this vehicle. When
driving in the U.S., to help keep the
engine clean and maintain optimum
vehicle performance, we
recommend using TOP TIER
Detergent Gasolines. See
www.toptiergas.com for a list of TOP
TIER Detergent Gasolines.
If the vehicle has a yellow fuel cap,
E85 or FlexFuel can be used in the
vehicle. SeeE85 or FlexFuel on
page 9-71.
Use regular unleaded gasoline
meeting ASTM specification D4814
with a posted octane rating of 87 or
higher. Do not use gasoline with an
octane rating below 87, as it may
cause engine damage and will lower
fuel economy.
Use of Seasonal Fuels
Use summer and winter fuels in the
appropriate season. The fuels
industry automatically modifies the
fuel for the appropriate season.
If fuel is left in the vehicle tank for
long periods of time, driving or
starting could be affected. Drive the
vehicle until the fuel is at one-half
tank or less, then refuel with the
current seasonal fuel.
Prohibited Fuels
Gasolines containing oxygenates
such as ethers and ethanol, as well
as reformulated gasolines, are available in some cities. If these
gasolines comply with the
previously described specification,
then they are acceptable to use.
However, E85 (85% ethanol) and
other fuels containing more than
15% ethanol must be used only in
FlexFuel vehicles.
{Caution
Do not use fuel containing
methanol. It can corrode metal
parts in the fuel system and also
damage plastic and rubber parts.
That damage would not be
covered under the vehicle
warranty.
Some gasolines, mainly high octane
racing gasolines, can contain an
octane-enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). Do not use
gasolines and/or fuel additives with
MMT as they can reduce spark plug
life and affect emission control
system performance. The

Black plate (77,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
Driving and Operating 9-77
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. 4. Reapply the brake pedal. Then
apply the parking brake and shift
into P (Park).
5. Release the brake pedal.Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks.
7. Stop and have someone pick up and store the chocks.
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule on
page 11-2. Things that are
especially important in trailer
operation are automatic
transmission fluid, engine oil, axle lubricant, belts, cooling system, and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Trailer Towing
Do not tow a trailer during break-in.
See
New Vehicle Break-In on
page 9-19.
{Warning
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly.
For example, if the trailer is too
heavy, the brakes may not work
well —or even at all. The driver
and passengers could be
seriously injured. The vehicle may
also be damaged; the resulting
repairs would not be covered by
(Continued)

Black plate (4,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
10-4 Vehicle Care
This vehicle has an airbag system.
Before attempting to do your own
service work, seeServicing the
Airbag-Equipped Vehicle on
page 3-40.
Keep a record with all parts receipts
and list the mileage and the date of
any service work performed. See
Maintenance Records on
page 11-15.
{Caution
Even small amounts of
contamination can cause damage
to vehicle systems. Do not allow
contaminants to contact the fluids,
reservoir caps, or dipsticks.
Hood
To open the hood:
1. Pull the handle with this symbol on it. It is inside the vehicle
under the steering wheel.
2. Go to the front of the vehicle tofind the secondary hood release.
The handle is under the front
edge of the hood near the
center. Push the handle to the
right and at the same time raise
the hood.
Before closing the hood, be sure all
the filler caps are on properly. Then
bring the hood from full open to
within 15 cm (6 in) from the closed
position, pause, and push the front
center of the hood with a swift, firm
motion to fully close the hood.

Black plate (10,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
10-10 Vehicle Care
2. Fully press the accelerator pedalslowly three times within
five seconds.
3. Display the OIL LIFE REMAINING on the DIC. If the
display shows 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
REMAINING 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. If a small leak is
suspected, then use the following
checking procedures to check the fluid level. However, if there is a
large leak, then it may be necessary
to have the vehicle towed to a
dealer service department and have
it repaired before driving the vehicle
further.
{Caution
Use of the incorrect automatic
transmission fluid may damage
the vehicle, and the damage may
not be covered by the vehicle
warranty. Always use the
automatic transmission fluid listed
in
Recommended Fluids and
Lubricants on page 11-12.
Change the fluid and filter at the
scheduled maintenance intervals
listed in Maintenance Schedule on
page 11-2. Be sure to use the
transmission fluid listed in
Recommended Fluids and
Lubricants on page 11-12.
How to Check Automatic
Transmission Fluid
{Caution
Too much or too little fluid can
damage the transmission. Too
much can mean that some of the
fluid could come out and fall on
hot engine parts or exhaust
system parts, starting a fire. Too
little fluid could cause the
transmission to overheat. Be sure
to get an accurate reading if
checking the transmission fluid.
Before checking the fluid level,
prepare the vehicle:
1. Start the engine and park the vehicle on a level surface. Keep
the engine running.
2. Apply the parking brake and place the shift lever in P (Park).
3. With your foot on the brake pedal, move the shift lever
through each gear range,

Black plate (13,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
Vehicle Care 10-13
Consistency of Readings
Always check the fluid level at least
twice using the procedure described
previously. Consistency (repeatable
readings) is important to maintaining
proper fluid level. If readings are still
inconsistent, contact the dealer.
Engine Air Cleaner/Filter
SeeEngine Compartment Overview
on page 10-5 for the location of the
engine air cleaner/filter.
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter at the
scheduled maintenance intervals
and replace it at the first oil change
after each 80 000 km (50,000 mi)
interval. See Maintenance Schedule
on page 11-2. If driving in dusty/dirty
conditions, inspect the filter at each
engine oil change.
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/filter,
remove the engine air cleaner/filter
from the vehicle by following
Steps 1-8. When the engine air
cleaner/filter is removed, lightly
shake it to release loose dust and
dirt. If the engine air cleaner/filter
remains covered with dirt, a new
filter is required. Never use
compressed air to clean the filter.
Replacing the Engine Air Cleaner/
Filter
1. Screws (4)
2. Electrical Connector
3. Air Duct Clamp
1. Locate the air cleaner/filter assembly. See Engine
Compartment Overview on
page 10-5.
2. Disconnect the outlet duct by loosening the air duct clamp (3).
3. Disconnect the electrical connector (2) and the connector
harness from the cover.
4. Remove the four screws (1) on top of the cover of the housing
and lift up the cover.
5. Remove the engine air cleaner/ filter from the housing. Take care
to dislodge as little dirt as
possible.
6. Clean the engine air cleaner/ filter sealing surfaces and the
housing.
7. Inspect or replace the engine air cleaner/filter.

Black plate (22,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
10-22 Vehicle Care
There are only two reasons why the
brake fluid level in the reservoir
might go down:
.The brake fluid level goes down
because of normal brake lining
wear. When new linings are
installed, the fluid level goes
back up.
.A fluid leak in the brake
hydraulic system can also cause
a low fluid level. Have the brake
hydraulic system fixed, since a
leak means that sooner or later
the brakes will not work well.
Do not top off the brake fluid.
Adding fluid does not correct a leak.
If fluid is added when the linings are
worn, there will be too much fluid
when new brake linings are
installed. Add or remove brake fluid,
as necessary, only when work is
done on the brake hydraulic system.
{Warning
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You
or others could be burned, and
the vehicle could be damaged.
Add brake fluid only when work is
done on the brake hydraulic
system. See “Checking Brake
Fluid” in this section.
When the brake fluid falls to a low
level, the brake warning light comes
on. See Brake System Warning
Light on page 5-21.
Refer to the Maintenance Schedule
to determine when to check the
brake fluid. See Maintenance
Schedule on page 11-2.
Checking Brake Fluid
Check brake fluid by looking at the
brake fluid reservoir. See Engine
Compartment Overview on
page 10-5.
The fluid level should be above
MIN. If it is not, have the brake
hydraulic system checked to see if
there is a leak.
After work is done on the brake
hydraulic system, make sure the
level is above MIN but not over the
MAX mark.
What to Add
Use only new DOT 3 brake fluid
from a sealed container. See
Recommended Fluids and
Lubricants on page 11-12.

Black plate (24,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
10-24 Vehicle Care
Extended Storage: Remove the
black, negative (−) cable from the
battery or use a battery trickle
charger.
Four-Wheel Drive
Transfer Case
When to Check Lubricant
Refer toMaintenance Schedule on
page 11-2 to determine when to
check the lubricant. How to Check Lubricant
Automatic Transfer Case
1. Fill Plug
2. Drain Plug
To get an accurate reading, the
vehicle should be on a level
surface.
If the level is below the bottom of
the fill plug (1) hole, located on the
transfer case, some lubricant will
need to be added. Add enough
lubricant to raise the level to the
bottom of the fill plug (1) hole. Use
care not to overtighten the plug. When to Change Lubricant
Refer to
Maintenance Schedule on
page 11-2 to determine how often to
change the lubricant.
What to Use
Refer to Recommended Fluids and
Lubricants on page 11-12 to
determine what kind of lubricant
to use.
Front Axle
When to Check and Change
Lubricant
It is not necessary to regularly
check front axle fluid unless a leak
is suspected, or an unusual noise is
heard. A fluid loss could indicate a
problem. Have it inspected and
repaired.
How to Check Lubricant
To get an accurate reading, the
vehicle should be on a level
surface.