automatic transmission GMC YUKON 2009 User Guide

Shifting Into Four-Wheel Drive High or
AUTO (Automatic Four-Wheel Drive)
Turn the knob to the Four-Wheel High or AUTO position.
This can be done at any speed, except when shifting
from Four-Wheel Drive Low. The indicator light will ash
while shifting. It will remain on when the shift is
completed.
Shifting Into Two-Wheel Drive High
Turn the knob to the Two-Wheel High position. This
can be done at any speed, except when shifting
from Four-Wheel Drive Low.
See shifting out of Four-Wheel Drive Low later in this
section for more information.
Shifting Into Four-Wheel Drive Low
When Four-Wheel Low is engaged, vehicle speed
should be kept below 45 mph (72 km/h). Extended
high-speed operation in 4L may damage or shorten
the life of the drivetrain.
To shift to the Four-Wheel Drive Low position, the ignition
must be in ON/RUN and the vehicle must be stopped or
moving less than 3 mph (5 km/h) with the transmissionin N (Neutral). The preferred method for shifting into
Four-Wheel Drive Low is to have the vehicle moving
1 to 2 mph (1.6 to 3.2 km/h). Turn the knob to the
Four-Wheel Drive Low position. You must wait for the
Four-Wheel Drive Low indicator light to stop ashing and
remain on before shifting the transmission into gear.
Notice:Shifting the transmission into gear before
the Four-Wheel Drive Low indicator light has
stopped ashing could damage the transfer case.
To help avoid damaging the vehicle, always wait for
the Four-Wheel Drive Low indicator light to stop
ashing before shifting the transmission into gear.
The vehicle may have signicant engagement noise
and bump when shifting between Four-Wheel Drive Low
and Four-Wheel Drive High ranges or from N (Neutral)
while the engine is running.
If the knob is turned to the Four-Wheel Drive Low
position when the vehicle is in gear and/or moving, the
Four-Wheel Drive Low indicator light will ash for
30 seconds and not complete the shift unless the vehicle
is moving less than 3 mph (5 km/h) and the transmission
is in N (Neutral). After 30 seconds the transfer case
will shift to Four-Wheel Drive High mode.
2-39

{CAUTION:
It can be dangerous to get out of the vehicle if the
automatic transmission shift lever is not fully in
P (Park) with the parking brake rmly set. The
vehicle can roll. Do not leave the vehicle when the
engine is running unless you have to. If you have
left the engine running, the vehicle can move
suddenly. You or others could be injured. To be
sure the vehicle will not move, even when you are
on fairly level ground, always set the parking
brake and move the shift lever to P (Park).
{CAUTION:
Four-wheel drive vehicles with the transfer case
in N (Neutral) will allow the vehicle to roll, even
if the automatic transmission shift lever is in
P (Park). So, be sure the transfer case is in a
drive gear — not in N (Neutral). Always set the
parking brake.Follow the proper steps to be sure the vehicle will not
move. SeeShifting Into Park on page 2-44.
If pulling a trailer, seeTowing a Trailer on page 4-52.
Mirrors
Manual Rearview Mirror
Hold the inside rearview mirror in the center to move it
for a clearer view behind your vehicle. Adjust the
mirror to avoid glare from the headlamps behind you.
Push the tab forward for daytime use and pull it for
nighttime use.
Automatic Dimming Rearview Mirror
The vehicle may have an automatic dimming rearview
mirror.
Vehicles with OnStar
®have three additional control
buttons for the OnStar®system. See your dealer/retailer
for more information about OnStar®and how to
subscribe to it. SeeOnStar®System on page 2-64for
more information about the services OnStar®provides.
2-48

The main components of the instrument panel are the following:
A.Outlet Adjustment on page 3-31.
B.Turn Signal/Multifunction Lever on page 3-7.
C.Instrument Panel Cluster on page 3-35.
D.Hazard Warning Flashers on page 3-6.
E. Shift Lever. SeeAutomatic Transmission Operation
on page 2-29.
F.Tow/Haul Mode on page 2-35(If Equipped).
G.Driver Information Center (DIC) on page 3-51.
H.Audio System(s) on page 3-83.
I.Exterior Lamps on page 3-14.
J.Dome Lamp Override on page 3-19.Instrument
Panel Brightness on page 3-18.Fog Lamps
on page 3-17(If Equipped).
K.Hood Release on page 5-12.
L. Integrated Trailer Brake Controller (If Equipped).
Towing a Trailer on page 4-52.
M. Automatic Transfer Case Control. (If Equipped).
SeeFour-Wheel Drive on page 2-37.N.Cruise Control on page 3-12.
O.Tilt Wheel on page 3-6.
P.Horn on page 3-6.
Q.Audio Steering Wheel Controls on page 3-136.
R.Climate Control System on page 3-22orDual
Automatic Climate Control System on page 3-25
(If Equipped).
S.Accessory Power Outlet(s) on page 3-20. Cigarette
Lighter (If Equipped). SeeAshtray(s) and Cigarette
Lighter on page 3-21.
T.StabiliTrak
®System on page 4-6(If Equipped).
Pedal Adjust Button (If Equipped). SeeAdjustable
Throttle and Brake Pedal on page 2-27.Ultrasonic
Rear Parking Assist (URPA) on page 2-53(If
Equipped). Heated Windshield Washer Fluid Button
(If Equipped). SeeWindshield Washer on
page 3-10.Power Assist Steps on page 2-17
(If Equipped).
U.Glove Box on page 2-74.
3-5

Headlamps on Reminder
A reminder chime will sound when the headlamps or
parking lamps are manually turned on and the ignition is
off and a door is open. To disable the chime, turn the
light off.
Daytime Running Lamps (DRL)
Daytime Running Lamps (DRL) can make it easier for
others to see the front of your vehicle during the day.
Fully functional daytime running lamps are required on all
vehicles rst sold in Canada.
The DRL system will come on when the following
conditions are met:
The ignition is on.
The exterior lamps control is in AUTO.
The transmission is not in P (Park).
The light sensor determines it is daytime.
When the DRL are on, only the DRL lamps will be on.
The taillamps, sidemarker, instrument panel lights,
and other lamps will not be on.
When it begins to get dark, the automatic headlamp
system will switch from DRL to the headlamps.To turn off the DRL lamps, turn the exterior lamps control
to the OFF position and then release. For vehicles rst
sold in Canada, the transmission must be in the P (Park)
position, before the DRL lamps can be turned off.
Automatic Headlamp System
When it is dark enough outside, the automatic headlamp
system turns on the headlamps at the normal brightness,
along with the taillamps, sidemarker, parking lamps,
and the instrument panel lights. The radio lights will also
be dim.
To turn off the automatic headlamp system, turn the
exterior lamps switch to the off position and then release
it. For vehicles rst sold in Canada, the transmission
must be in the P (Park) position, before the automatic
headlamp system can be turned off.
The vehicle has a light sensor located on the top of the
instrument panel in the defroster grille that regulates
when the automatic headlamps turn on. Do not cover the
sensor or the headlamps will come on whenever the
ignition is on.
The system may also turn on the headlamps when
driving through a parking garage, heavy overcast
weather, or a tunnel. This is normal.
3-16

Transmission Temperature
Press the trip/fuel button until TRANS TEMP displays.
This display shows the temperature of the automatic
transmission uid in either degrees Fahrenheit (°F) or
degrees Celsius (°C).
Blank Display
This display shows no information.
Vehicle Information Menu Items
T
(Vehicle Information):Press this button to scroll
through the following menu items:
Oil Life
Press the vehicle information button until OIL LIFE
REMAINING displays. This display shows an estimate of
the oil’s remaining useful life. If you see 99% OIL LIFE
REMAINING on the display, that means 99% of the
current oil life remains. The engine oil life system will alert
you to change the oil on a schedule consistent with your
driving conditions.
When the remaining oil life is low, the CHANGE ENGINE
OIL SOON message will appear on the display. See
“CHANGE ENGINE OIL SOON” underDIC Warnings
and Messages on page 3-64. You should change the
oil as soon as you can. SeeEngine Oil on page 5-15.In addition to the engine oil life system monitoring the oil
life, additional maintenance is recommended in the
Maintenance Schedule in this manual. SeeScheduled
Maintenance on page 6-4for more information.
Remember, you must reset the OIL LIFE display
yourself after each oil change. It will not reset itself.
Also, be careful not to reset the OIL LIFE display
accidentally at any time other than when the oil has just
been changed. It cannot be reset accurately until the
next oil change. To reset the engine oil life system, see
Engine Oil Life System on page 5-18.
Side Blind Zone Alert
If your vehicle has the Side Blind Zone Alert (SBZA)
system, this display allows the system to be turned on or
off. Once in this display, press the set/reset button to
select between ON or OFF. If you choose ON, the
system will be turned on. If you choose OFF, the system
will be turned off. When the SBZA system is turned
off, the DIC will display the SIDE BLIND ZONE ALERT
SYSTEM OFF message as a reminder that the
system has been turned off. SeeDIC Warnings and
Messages on page 3-64andSide Blind Zone Alert
(SBZA) on page 2-56for more information.
3-55

Transmission Temperature
Press the trip odometer reset stem until TRANS
TEMP displays. This display shows the temperature
of the automatic transmission uid in either degrees
Fahrenheit (°F) or degrees Celsius (°C).
Trailer Gain and Output
On vehicles with the Integrated Trailer Brake Control
(ITBC) system, the trailer brake display appears in the
DIC. Press the trip odometer reset stem until TRAILER
GAIN and OUTPUT display.
TRAILER GAIN shows the trailer gain setting. This
setting can be adjusted from 0.0 to 10.0 with either a
trailer connected or disconnected. To adjust this setting,
see “Integrated Trailer Brake Control System” under
Towing a Trailer on page 4-52for more information.OUTPUT shows the power output to the trailer anytime
a trailer with electric brakes is connected. Output is
displayed in 0 to 10 bars. Dashes may appear in
the OUTPUT display. See “Integrated Trailer Brake
Control System” underTowing a Trailer on page 4-52
for more information.
Compass Zone Setting
This display allows for setting the compass zone. See
DIC Compass on page 3-61for more information.
Compass Recalibration
This display allows for calibrating the compass. SeeDIC
Compass on page 3-61for more information.
3-59

It is recommended to leave the system on for normal
driving conditions, but it may be necessary to turn the
system off if the vehicle is stuck in sand, mud, ice or
snow, and you want to “rock” the vehicle to attempt to
free it. It may also be necessary to turn off the system
when driving in extreme off-road conditions where high
wheel spin is required. SeeIf Your Vehicle is Stuck in
Sand, Mud, Ice, or Snow on page 4-31
Traction Control Operation
The traction control system is part of the StabiliTrak
system. Traction control limits wheel spin by reducing
engine power to the wheels (engine speed management)
and by applying brakes to each individual wheel
(brake-traction control) as necessary.
The traction control system is enabled automatically
when the vehicle is started. It will activate and the
StabiliTrak light will ash if it senses that any of the
wheels are spinning or beginning to lose traction while
driving. If traction control is turned off, only the
brake-traction control portion of traction control will
work. The engine speed management will be disabled.
In this mode, engine power is not reduced automatically
and the driven wheels can spin more freely. This can
cause the brake-traction control to activate constantly.Notice:If the wheel(s) of one axle is allowed to spin
excessively while the StabiliTrak, ABS and brake
warning lights and any relevant DIC messages are
displayed, the transfer case could be damaged. The
repairs would not be covered by the vehicle warranty.
Reduce engine power and do not spin the wheel(s)
excessively while these lights and messages are
displayed.
The traction control system may activate on dry or rough
roads or under conditions such as heavy acceleration
while turning or abrupt upshifts/downshifts of the
transmission. When this happens, a reduction in
acceleration may be noticed, or a noise or vibration
may be heard. This is normal.
If cruise control is being used when the system activates,
the StabiliTrak light will ash and cruise control will
automatically disengage. Cruise control may be
reengaged when road conditions allow. SeeCruise
Control on page 3-12
StabiliTrak may also turn off automatically if it determines
that a problem exists with the system. If the problem does
not clear itself after restarting the vehicle, see your
dealer/retailer for service.
4-8

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

Leaving After Parking on a Hill
1. Apply and hold the brake pedal while you:
Start the engine
Shift into a gear
Release the parking brake
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. 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 this manual’s Maintenance Schedule
or Index for more information. Things that are especially
important in trailer operation are automatic transmission
uid, 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 Wiring Harness
The vehicle is equipped with the following wiring
harnesses for towing a trailer.
Basic Trailer Wiring
The trailer wiring harness, with a seven-pin connector,
is located at the rear of the vehicle and is tied to
the vehicle’s frame. The harness connector can be
plugged into a seven-pin universal heavy-duty trailer
connector available through your dealer/retailer.
The seven-wire harness contains the following trailer
circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Taillamps
White: Ground
Light Green: Back-up Lamps
Red: Battery Feed*
Dark Blue: Trailer Brake*
*The fuses for these two circuits are installed in the
underhood electrical center, but the wires are not
connected. They should be connected by your
dealer/retailer or a qualied service center.
4-71

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