engine GMC YUKON 2012 Owner's Manual

Black plate (9,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-9
has so much oil that the oil level
gets above the cross-hatched
area that shows the proper
operating range, the engine could
be damaged. You should drain
out the excess oil or limit driving
of the vehicle and seek a service
professional to remove the
excess amount of oil.
SeeEngine Compartment Overview
on page 10‑6 for the location of the
engine oil fill cap.
Add enough oil to put the level
somewhere in the proper operating
range. Push the dipstick all the way
back in when through.
Selecting the Right Engine Oil
Selecting the right engine oil
depends on both the proper oil
specification and viscosity grade.
See Recommended Fluids and
Lubricants on page 11‑11. Specification
Use and ask for licensed engine
oils with the dexos1™
approved
certification mark. Engine oils
meeting the requirements for the
vehicle should have the dexos1
approved certification mark. This
certification mark indicates that the
oil has been approved to the dexos1
specification.
Notice: Failure to use the
recommended engine oil or
equivalent can result in engine
damage not covered by the
vehicle warranty. Check with your
dealer or service provider on
whether the oil is approved to
the dexos1 specification. Viscosity Grade
SAE 5W‐30 is the best viscosity
grade for the vehicle. Do not use
other viscosity grade oils such as
SAE 10W‐30, 10W‐40, or 20W‐50.
If in an area of extreme cold, where
the temperature falls below
−20°F
(−29°C), an SAE 0W‐30 oil should
be used. An oil of this viscosity
grade will provide easier cold
starting for the engine at extremely
low temperatures. When selecting
an oil of the appropriate viscosity
grade, always select an oil that
meets the dexos1 specification or
equivalent. See “Specification”for
more information.

Black plate (10,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-10 Vehicle Care
Engine Oil Additives/Engine
Oil Flushes
Do not add anything to the oil. The
recommended oils with the dexos
specification and displaying the
dexos certification mark are all that
is needed for good performance and
engine protection.
Engine oil system flushes are not
recommended and could cause
engine damage not covered by the
vehicle warranty.
What to Do with Used Oil
Used engine oil contains certain
elements that can be unhealthy for
your skin and could even cause
cancer. Do not let used oil stay on
your skin for very long. Clean your
skin and nails with soap and water,
or a good hand cleaner. Wash or
properly dispose of clothing or rags
containing used engine oil. See the
manufacturer's warnings about the
use and disposal of oil products.
Used oil can be a threat to the
environment. If you change your
own oil, be sure to drain all the oil
from the filter before disposal. Never
dispose of oil by putting it in the
trash or pouring it on the ground,
into sewers, or into streams or
bodies of water. Recycle it by taking
it to a place that collects used oil.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system
that indicates when to change the
engine oil and filter. This is based
on a combination of factors which
include engine revolutions, engine
temperature, and miles driven.
Based on driving conditions, the
mileage at which an oil change is
indicated can vary considerably. For
the oil life system to work properly,
the system must be reset every time
the oil is changed.
On some vehicles, when the system
has calculated that oil life has been
diminished, a CHANGE ENGINE
OIL SOON message comes on to
indicate that an oil change is
necessary. SeeEngine Oil
Messages on page 5‑40. Change
the oil as soon as possible within
the next 1 000 km (600 mi).

Black plate (11,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-11
It is possible that, if driving under
the best conditions, the oil life
system might indicate that an oil
change is not necessary for up to a
year. The engine oil and filter must
be changed at least once a year
and, at this time, the system must
be reset. For vehicles without
the CHANGE ENGINE OIL
SOON message, an oil change is
needed when the OIL LIFE
REMAINING percentage is near
0%. Your dealer has trained service
people who will perform this work
and reset the system. It is also
important to check the oil regularly
over the course of an oil drain
interval and keep it at the proper
level.
If the system is ever reset
accidentally, the oil must be
changed at 5 000 km (3,000 mi)
since the last oil change.
Remember to reset the oil life
system whenever the oil is changed.How to Reset the Engine Oil
Life System
Reset the system whenever the
engine oil is changed so that the
system can calculate the next
engine oil change. Always reset the
engine oil life to 100% after every oil
change. It will not reset itself. To
reset the system on most vehicles:
1. Display the OIL LIFEREMAINING on the DIC. If the
vehicle does not have DIC
buttons, the vehicle must be in
P (Park) to access this display.
See Driver Information Center
(DIC) on page 5‑29.
2. Press and hold the SET/RESET button on the DIC, or the trip
odometer reset stem if the
vehicle does not have DIC
buttons, for more than
five seconds. The oil life
will change to 100%. On all vehicles, the Engine Oil Life
System can be reset as follows:
1. Turn the ignition to ON/RUN with
the engine off.
2. Fully press the accelerator pedal slowly three times within
five seconds.
3. Display the OIL LIFE REMAINING on the DIC. If the
display shows 100%, the system
is reset. See Driver Information
Center (DIC) on page 5‑29.
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.

Black plate (12,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-12 Vehicle Care
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 and have it repaired before
driving the vehicle further.
Notice:Use of the incorrect
automatic transmission fluid may
damage the vehicle, and the
damages may not be covered by
the vehicle warranty. Always use
the automatic transmission fluid
listed in Recommended Fluids
and Lubricants on page 11‑11. Change the fluid and filter at the
scheduled maintenance intervals
listed in
Maintenance Schedule on
page 11‑3. Be sure to use the
transmission fluid listed in
Recommended Fluids and
Lubricants on page 11‑11.
How to Check Automatic
Transmission Fluid
Notice: 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 as follows:
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,
pausing for about three seconds
in each range. Then, move the
shift lever back to P (Park).
4. Allow the engine to idle (500 –800 rpm) for at least
1 minute. Slowly release the
brake pedal.
5. Keep the engine running and press the Trip/Fuel button or
trip odometer reset stem until
TRANS TEMP (Transmission
Temperature) displays on the
Driver Information Center (DIC).

Black plate (13,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-13
6. Using the TRANS TEMPreading, determine and
perform the appropriate check
procedure. If the TRANS TEMP
reading is not within the required
temperature ranges, allow the
vehicle to cool, or operate the
vehicle until the appropriate
transmission fluid temperature is
reached.
Cold Check Procedure
Use this procedure only as a
reference to determine if the
transmission has enough fluid to be
operated safely until a hot check
procedure can be made. The hot
check procedure is the most
accurate method to check the fluid
level. Perform the hot check
procedure at the first opportunity.
Use this cold check procedure to
check fluid level when the
transmission temperature is
between 27°C and 32°C
(80°F and 90°F).
1. Locate the transmission dipstick at the rear of the engine
compartment, on the passenger
side of the vehicle.
See Engine Compartment
Overview on page 10‑6 for more
information.
2. Flip the handle up, then pull out the dipstick and wipe it with a
clean rag or paper towel.
3. Install the dipstick by pushing it back in all the way; wait
three seconds, and then pull it
back out again.
4. Check both sides of the dipstick and read the lower level. Repeat
the check procedure to verify the
reading.5. If the fluid level is below theCOLD check band, add only
enough fluid as necessary to
bring the level into the COLD
band. It does not take much
fluid, generally less than 0.5 L
(1 pt). Do not overfill.
6. Perform a hot check at the first opportunity after the
transmission reaches a normal
operating temperature between
71°C to 93°C (160°F to 200°F).
7. If the fluid level is in the acceptable range, push the
dipstick back in all the way, then
flip the handle down to lock the
dipstick in place.

Black plate (14,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-14 Vehicle Care
Hot Check Procedure
Use this procedure to check the
transmission fluid level when the
transmission fluid temperature is
between 71°C and 93°C (160°F
and 200°F).
The hot check is the most accurate
method to check the fluid level. The
hot check should be performed at
the first opportunity in order to verify
the cold check. The fluid level rises
as fluid temperature increases,
so it is important to ensure the
transmission temperature is within
range.
1. Locate the transmission dipstickat the rear of the engine
compartment, on the passenger
side of the vehicle.
See Engine Compartment
Overview on page 10‑6 for more
information.
2. Flip the handle up, then pull out the dipstick and wipe it with a
clean rag or paper towel.
3. Install the dipstick by pushing it back in all the way; wait
three seconds, and then pull it
back out again.
4. Check both sides of the dipstick and read the lower level. Repeat
the check procedure to verify the
reading.5. Safe operating level is within theHOT cross hatch band on the
dipstick. If the fluid level is not
within the HOT band, and the
transmission temperature is
between 71°C and 93°C (160°F
and 200°F), add or drain fluid as
necessary to bring the level into
the HOT band. If the fluid level is
low, add only enough fluid to
bring the level into the HOT
band. It does not take much
fluid, generally less than 0.5 L
(1 pt). Do not overfill.
6. If the fluid level is in the acceptable range, push the
dipstick back in all the way, then
flip the handle down to lock the
dipstick in place.

Black plate (15,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-15
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 10‑6 for the location of 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 11‑3 for more information.
If driving on 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 through 6. 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. Locate the air cleaner/filter
assembly. See Engine
Compartment Overview on
page 10‑6.
2. Loosen the four screws on the cover of the housing and lift up
the cover.

Black plate (16,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-16 Vehicle Care
3. Remove the engine air cleaner/filter from the housing. Care
should be taken to dislodge as
little dirt as possible.
4. Clean the engine air cleaner/ filter sealing surfaces and the
housing.
5. Inspect or replace the engine air cleaner/filter.
6. Reinstall the cover and tighten the screws.
{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.
Cooling System
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
The cooling system allows the
engine to maintain the correct
working temperature.
5.3L V8 Engine Shown, 6.0L
V8 Engine Similar
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan(s) (Out of View)

Black plate (17,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-17
{WARNING
An electric engine cooling fan
under the hood 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
Heater and radiator hoses, and
other engine parts, can be very
hot. Do not touch them. If you do,
you can be burned.(Continued)
WARNING (Continued)
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.
Notice: Using coolant other than
DEX-COOL
®can cause premature
engine, heater core, or radiator
corrosion. In addition, the engine
coolant could require changing
sooner, at 50 000 km (30,000 mi)
or 24 months, whichever occurs
first. 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 10‑21.

Black plate (18,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-18 Vehicle Care
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.
Notice: If an improper coolant
mixture is used, the engine could
overheat and be badly damaged.
The repair cost would not be
covered by the vehicle warranty.
Too much water in the mixture
can freeze and crack the engine,
radiator, heater core, and other
parts. Notice:
If extra inhibitors and/or
additives are used in the vehicle
cooling system, the vehicle
could be damaged. Use only the
proper mixture of the engine
coolant listed in this manual for
the cooling system. See
Recommended Fluids and
Lubricants on page 11‑11 for
more information.
Never dispose of engine coolant
by putting it in the trash, 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.