2009 GMC YUKON warning

The Trailer Brake Display Page can be displayed by
performing any of the following actions:
Scrolling through the DIC menu pages using the
odometer trip stem or the DIC Vehicle Information
button (if equipped).
Pressing a Trailer Gain button – If the Trailer Brake
Display Page is not currently displayed, pressing a
Trailer Gain button will rst recall the current
Trailer Gain setting. After the Trailer Brake Display
Page is displayed, each press and release of
the gain buttons will then cause the Trailer Gain
setting to change.
Activating the Manual Trailer Brake Apply lever
Connecting a trailer equipped with electric trailer
brakes
All DIC warning and service messages must rst be
acknowledged by the driver by pressing the odometer trip
stem or the DIC Vehicle Information button (if equipped)
before the Trailer Brake Display Page can be displayed
and Trailer Gain can be adjusted.
TRAILER GAIN – This setting is displayed anytime the
Trailer Brake Display Page is active. This setting can be
adjusted from 0.0 to 10.0 with either a trailer connected or
disconnected. To adjust the Trailer Gain, press one of the
Trailer Gain adjustment buttons located on the TrailerBrake Control Panel. Press and hold a gain button to
cause the Trailer Gain to continuously adjust. To turn the
output to the trailer off, adjust the Trailer Gain setting to
0.0 (zero).
0.0 (zero) gain is the factory default setting. To properly
adjust trailer gain, see the Trailer Gain Adjustment
Procedure later in this section.
TRAILER OUTPUT – This is displayed any time a trailer
with electric brakes is connected. Output to the electric
brakes is based on the amount of vehicle braking
present and relative to the Trailer Gain setting. Output is
displayed from 0 to 10 bars for each gain setting.
The Trailer Output will indicate “------“ontheTrailer
Brake Display Page whenever the following occur:No trailer is connected.
A trailer without electric brakes is connected (no
DIC message is displayed).
A trailer with electric brakes has become
disconnected (a CHECK TRAILER WIRING
message will also be displayed on the DIC).
There is a fault present in the wiring to the electric
trailer brakes (a CHECK TRAILER WIRING
message will also be displayed on the DIC).
There is a fault in the ITBC system (a SERVICE
TRAILER BRAKE SYSTEM message will also
be displayed in the DIC).
4-64

Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, move that hand
to the left. To move the trailer to the right, move your
hand to the right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. 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.
Turn Signals When Towing a Trailer
The arrows on the instrument panel ash whenever
signaling a turn or lane change. Properly hooked up, the
trailer lamps also ash, telling other drivers the vehicle
is turning, changing lanes or stopping.
When towing a trailer, the arrows on the instrument
panel ash for turns even if the bulbs on the trailer are
burned out. For this reason you may think other
drivers are seeing the signal when they are not. 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 gearbeforestarting
down a long or steep downgrade. If the transmission is
not shifted down, the brakes might have to be used so
much that they would 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.
The tow/haul mode may be used if the transmission
shifts too often. SeeTow/Haul Mode Light on page 3-49.
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 automatic
transmission in P (Park) for a few minutes before turning
the engine off. If the overheat warning comes on, see
Engine Overheating on page 5-35.
4-69

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-4
California Perchlorate Materials
Requirements.............................................5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of
the Vehicle.................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-6
Fuel E85 (85% Ethanol)..................................5-7
Fuels in Foreign Countries...............................5-8
Filling the Tank..............................................5-9
Filling a Portable Fuel Container.....................5-11
Checking Things Under the Hood....................5-12
Hood Release..............................................5-12
Engine Compartment Overview.......................5-14
Engine Oil...................................................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter................................5-19
Automatic Transmission Fluid (4-Speed
Transmission)...........................................5-21Automatic Transmission Fluid (6-Speed
Transmission)...........................................5-24
Cooling System............................................5-28
Engine Coolant.............................................5-29
Engine Overheating.......................................5-35
Overheated Engine Protection
Operating Mode........................................5-37
Engine Fan Noise.........................................5-38
Power Steering Fluid.....................................5-38
Windshield Washer Fluid................................5-39
Brakes........................................................5-41
Battery........................................................5-44
Jump Starting...............................................5-45
Rear Axle.......................................................5-50
Four-Wheel Drive............................................5-52
Front Axle......................................................5-53
Headlamp Aiming...........................................5-54
Bulb Replacement..........................................5-57
Halogen Bulbs..............................................5-57
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps.........................................5-58
License Plate Lamp......................................5-59
Replacement Bulbs.......................................5-60
Windshield Wiper Blade Replacement..............5-60
Section 5 Service and Appearance Care
5-1

California Proposition 65 Warning
Most motor vehicles, including this one, contain and/or
emit chemicals known to the State of California to
cause cancer and birth defects or other reproductive
harm. Engine exhaust, many parts and systems
(including some inside the vehicle), many uids, and
some component wear by-products contain and/or emit
these chemicals.
California Perchlorate Materials
Requirements
Certain types of automotive applications, such as airbag
initiators, seat belt pretensioners, and lithium batteries
contained in remote keyless transmitters, may contain
perchlorate materials. Special handling may be
necessary. For additional information, see
www.dtsc.ca.gov/hazardouswaste/perchlorate.
Doing Your Own Service Work
If this vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
{CAUTION:
You can be injured and the vehicle could be
damaged if you try to do service work on a vehicle
without knowing enough about it.
Be sure you have sufficient knowledge,
experience, the proper replacement parts, and
tools before attempting any vehicle
maintenance task.
Be sure to use the proper nuts, bolts, and
other fasteners. English and metric fasteners
can be easily confused. If the wrong fasteners
are used, parts can later break or fall off. You
could be hurt.
If doing some of your own service work, use the proper
service manual. It tells you much more about how to
service the vehicle than this manual can. To order
the proper service manual, seeService Publications
Ordering Information on page 7-15.
5-4

Engine Oil Additives / Engine Oil
Flushes
Do not add anything to the oil. The recommended oils
with the starburst symbol that meet GM Standard
GM6094M are all that is needed for good performance
and engine protection.
Engine oil system ushes are not recommended and
could cause engine damage not covered by the vehicle
warranty.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system that indicates when
to change the engine oil and lter. This is based on
engine revolutions and engine temperature, and not on
mileage. 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.When the system has calculated that oil life has been
diminished, it indicates that an oil change is necessary.
A CHANGE ENGINE OIL SOON message comes on.
SeeDIC Warnings and Messages on page 3-64.
Change the oil as soon as possible within the next
600 miles (1 000 km). It is possible that, if driving under
the best conditions, the oil life system might not
indicate that an oil change is necessary for over a year.
However, the engine oil and lter must be changed
at least once a year and at this time the system must
be reset. Your dealer/retailer has trained service people
who will perform this work using genuine parts and
reset the system. It is also important to check the oil
regularly and keep it at the proper level.
If the system is ever reset accidentally, the oil must be
changed at 3,000 miles (5 000 km) since the last oil
change. Remember to reset the oil life system whenever
the oil is changed.
5-18

How to Reset the Engine Oil Life
System
The Engine Oil Life System calculates when to change
the engine oil and lter based on vehicle use. Whenever
the oil is changed, reset the system so it can calculate
when the next oil change is required. If a situation occurs
where the oil is changed prior to a CHANGE ENGINE OIL
SOON message coming on, reset the system.
Always reset the engine oil life to 100% after every oil
change. It will not reset itself. To reset the Engine
Oil Life System:
1. Display the OIL LIFE REMAINING on the DIC. If
the vehicle does not have DIC buttons, the vehicle
must be in P (Park) to access this display. See
DIC Operation and Displays (With DIC Buttons) on
page 3-52orDIC Operation and Displays (Without
DIC Buttons) on page 3-57.
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 ve seconds.
The oil life will change to 100%.
If the CHANGE ENGINE OIL SOON message comes
back on when the vehicle is started, the Engine Oil Life
System has not reset. Repeat the procedure.
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
lter before disposal. Never dispose of oil by putting it in
the trash, 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 Air Cleaner/Filter
SeeEngine Compartment Overview on page 5-14for
the location of the engine air cleaner/lter.
Inspect the air cleaner/lter at the MaintenanceII
intervals and replace it at the rst oil change after each
50,000 mile (80 000 km) interval. SeeScheduled
Maintenance on page 6-4for more information. If driving
on dusty/dirty conditions, inspect the lter at each
engine oil change.
5-19

What to Use
{CAUTION:
Adding only plain water to the cooling system can
be dangerous. Plain water, or some other liquid
such as alcohol, can boil before the proper coolant
mixture will. The vehicle’s 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 re 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−34°F (−37°C),
outside temperature.
Gives boiling protection up to 265°F (129°C),
engine temperature.
Protects against rust and corrosion.
Will not damage aluminum parts.
Helps keep the proper engine temperature.
5-30

5. Replace the pressure cap. Be sure the pressure
cap is hand-tight and fully seated.
6. Verify coolant level after engine is shut off and the
coolant is cold. If necessary, repeat coolant ll
procedure Steps 1 through 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 gage on your vehicle’s
instrument panel. SeeEngine Coolant Temperature
Gage on page 3-43.
In addition, ENGINE OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE ENGINE, and a ENGINE
POWER IS REDUCED message comes on in the
Driver Information Center (DIC) on the instrument panel.
SeeDIC Warnings and Messages on page 3-64.You may decide not to lift the hood when this warning
appears, but instead get service help right away.
SeeRoadside Assistance Program on page 7-7.
If you do decide 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:Engine damage from running your engine
without coolant is not covered by your warranty. See
Overheated Engine Protection Operating Mode on
page 5-37for information on driving to a safe place
in an emergency.
Notice:If the engine catches re while driving with
no coolant, the vehicle can be badly damaged.
The costly repairs would not be covered by
the vehicle warranty. SeeOverheated Engine
Protection Operating Mode on page 5-37for
information on driving to a safe place in an
emergency.
5-35