transmission GMC YUKON XL 2008 Owner's Manual

A. Air Outlets. SeeOutlet Adjustment on page 3-33.
B. Turn Signal/Multifunction Lever. SeeTurn
Signal/Multifunction Lever on page 3-7.
C. Instrument Panel Cluster. SeeInstrument Panel
Cluster on page 3-38.
D. Hazard Warning Flasher Button. SeeHazard
Warning Flashers on page 3-6.
E. Shift Lever. SeeAutomatic Transmission Operation
on page 2-31.
F. Tow/Haul Selector Button (If Equipped). See
Tow/Haul Mode on page 2-37.
G. Driver Information Center Controls. SeeDriver
Information Center (DIC) on page 3-55.
H. Audio System. SeeAudio System(s) on page 3-81.
I. Exterior Lamps Control. SeeExterior Lamps on
page 3-16.
J. Dome Lamp Override Button. SeeDome Lamp
Override on page 3-20. Instrument Panel Brightness
Control. SeeInstrument Panel Brightness on
page 3-20. Fog Lamp Button (If Equipped). SeeFog
Lamps on page 3-19.
K. Automatic Transfer Case Control. (If Equipped). See
Four-Wheel Drive on page 2-38.L. Cruise Control Buttons. SeeCruise Control on
page 3-13.
M. Tilt Wheel Lever. SeeTilt Wheel on page 3-6.
N. Horn. SeeHorn on page 3-6.
O. Audio Steering Wheel Controls. SeeAudio Steering
Wheel Controls on page 3-128.
P. Climate Controls. SeeClimate Control System on
page 3-23or Dual Automatic Climate Controls
(If Equipped). SeeDual Automatic Climate Control
System on page 3-26.
Q. Accessory Power Outlets. SeeAccessory Power
Outlet(s) on page 3-22. Cigarette Lighter (If
Equipped). SeeAshtray(s) and Cigarette Lighter on
page 3-23.
R. StabiliTrak
®Button (If Equipped). SeeStabiliTrak®
System on page 4-6. Pedal Adjust Button (If
Equipped). SeeAdjustable Throttle and Brake Pedal
on page 2-29. Rear Park Assist Disable Button (If
Equipped). SeeUltrasonic Rear Parking Assist
(URPA) on page 2-58. Heated Windshield Washer
Fluid Button (If Equipped). SeeWindshield Washer on
page 3-11. Power Running Boards Disable Button (If
Equipped). SeePower Running Boards on page 2-18.
S. Glove Box. SeeGlove Box on page 2-71.
3-5

;(Parking Lamps):Turn the control to this position
to turn on the parking lamps together with the
following:
Instrument Panel Lights
Taillamps
License Plate Lamps
2(Headlamps):Turn the control to this position to
turn on the headlamps together with the following lamps
listed below.
Parking Lamps
Instrument Panel Lights
Taillamps
License Plate Lamps
When the headlamps are turned on while the vehicle is
on, the headlamps turn off automatically 10 minutes
after the ignition is turned off. When the headlamps are
turned on while the vehicle is off, the headlamps will
stay on for 10 minutes before automatically turning off to
prevent the battery from being drained.
Headlamps on Reminder
A reminder chime will sound when the headlamps or
parking lamps are manually turned on and your 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. DRL can be helpful in many different driving
conditions, but they can be especially helpful in the short
periods after dawn and before sunset. 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 PARK (P).
The light sensor determines it is daytime.
When the DRL are on, only the DRL lamps will be on.
The taillamps, sidemarker, and other lamps will not
be on. The instrument panel will not be lit up either.
3-17

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 PARK (P) position, before the DRL lamps can
be turned off.
Automatic Headlamp System
When it is dark enough outside, the automatic headlamp
system will turn 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 PARK (P) 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. Be sure it is not
covered, 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.There is a delay in the transition between the daytime
and nighttime operation of the Daytime Running
Lamps (DRL) and the automatic headlamp systems so
that driving under bridges or bright overhead street
lights does not affect the system. The DRL and
automatic headlamp system will only be affected when
the light sensor detects a change in lighting lasting
longer than the delay.
If the vehicle is started in a dark garage, the automatic
headlamp system will come on immediately. Once
the vehicle leaves the garage, it takes approximately
one minute for the automatic headlamp system to
change to DRL if it is bright enough outside. During that
delay, the instrument panel cluster may not be as
bright as usual. Make sure the instrument panel
brightness control is in the full bright position. See
Instrument Panel Brightness on page 3-20.
To idle the vehicle with the automatic headlamp system
off, turn the control to the off position.
The headlamps will also stay on after you exit the
vehicle. This feature can be programmed using the
Driver Information Center (DIC). SeeDIC Vehicle
Customization (With DIC Buttons) on page 3-72.
The regular headlamp system can be turned on when
needed.
3-18

Malfunction Indicator Lamp
Check Engine Light
A computer system called OBD II (On-Board
Diagnostics-Second Generation) monitors operation of
the fuel, ignition, and emission control systems. It makes
sure that emissions are at acceptable levels for the life of
the vehicle, helping to produce a cleaner environment.
The check engine light
comes on to indicate that
there is an OBD II
problem and service is
required.
Malfunctions often are indicated by the system before
any problem is apparent. This can prevent more serious
damage to your vehicle. This system is also designed
to assist your service technician in correctly diagnosing
any malfunction.Notice:If you keep driving your vehicle with this
light on, after a while, the emission controls
might not work as well, your vehicle’s fuel economy
might not be as good, and the engine might not
run as smoothly. This could lead to costly repairs
that might not be covered by your warranty.
Notice:Modications made to the engine,
transmission, exhaust, intake, or fuel system of
your vehicle or the replacement of the original tires
with other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and can cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This could
also result in a failure to pass a required Emission
Inspection/Maintenance test. SeeAccessories
and Modifications on page 5-3.
3-48

DIC Operation and Displays
(With DIC Buttons)
If your vehicle has DIC buttons, the information below
explains the operation of this system.
The DIC has different displays which can be accessed
by pressing the DIC buttons located on the instrument
panel, next to the steering wheel.
The DIC displays trip, fuel, and vehicle system
information, and warning messages if a system problem
is detected.
The DIC also allows some features to be customized.
SeeDIC Vehicle Customization (With DIC Buttons)
on page 3-72for more information.
If your vehicle has DIC buttons, you can also use the
trip odometer reset stem to view some of the DIC
displays. See “DIC Operation and Displays (Without DIC
Buttons)” later in this section.
DIC Buttons
The buttons are the
trip/fuel, vehicle
information, customization,
and set/reset buttons.
The button functions are
detailed in the following
pages.
3(Trip/Fuel):Press this button to display the
odometer, trip odometer, fuel range, average economy,
fuel used, timer, and transmission temperature.
Some vehicles also display instantaneous economy and
an Active Fuel Management™ indicator.
T(Vehicle Information):Press this button to display
the oil life, units, tire pressure readings, engine hours,
and Remote Keyless Entry (RKE) transmitter
programming.
3-56

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).
Instantaneous Economy and Active Fuel
Management™ Indicator
If your vehicle has this display, press the trip/fuel button
until INST ECONOMY V8 MODE displays. This
display shows the current fuel economy at a particular
moment and will change frequently as driving conditions
change. This display shows the instantaneous fuel
economy in miles per gallon (mpg) or liters per
100 kilometers (L/100 km). Unlike average economy,
this screen cannot be reset.
An Active Fuel Management™ indicator will display on
the right side of the DIC, while INST ECONOMY
displays on the left side. Active Fuel Management™
allows the engine to operate on either four or eight
cylinders, depending on your driving demands. When
Active Fuel Management™ is active, V4 MODE will
display on the DIC. When Active Fuel Management™ is
inactive, V8 MODE will display. SeeActive Fuel
Management™ on page 2-31for more information.
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.
3-59

TRANSMISSION HOT IDLE ENGINE
Notice:If you drive your vehicle while the
transmission uid is overheating and the
transmission temperature warning is displayed on
the instrument panel cluster and/or DIC, you
can damage the transmission. This could lead to
costly repairs that would not be covered by
your warranty. Do not drive your vehicle with
overheated transmission uid or while the
transmission temperature warning is displayed.
This message displays along with a continuous chime if
the transmission uid in the vehicle gets hot. Driving
with the transmission uid temperature high can cause
damage to the vehicle. Stop the vehicle and let it
idle to allow the transmission to cool. This message
clears and the chime stops when the uid temperature
reaches a safe level.
TURN SIGNAL ON
This message displays and a chime sounds if a turn
signal is left on for 3/4 of a mile (1.2 km). Move the turn
signal/multifunction lever to the off position.
WASHER FLUID LOW ADD FLUID
This message displays when the windshield washer
uid is low. Fill the windshield washer uid reservoir as
soon as possible. SeeEngine Compartment Overview
on page 5-14for the location of the windshield
washer uid reservoir. Also, seeWindshield Washer
Fluid on page 5-40for more information.
DIC Vehicle Customization
(With DIC Buttons)
Your vehicle may have customization capabilities that
allow you to program certain features to one preferred
setting. Customization features can only be programmed
to one setting on the vehicle and cannot be programmed
to a preferred setting for two different drivers.
All of the customization options may not be available on
your vehicle. Only the options available will be
displayed on the DIC.
The default settings for the customization features were
set when your vehicle left the factory, but may have
been changed from their default state since then.
The customization preferences are automatically
recalled.
To change customization preferences, use the following
procedure.
3-72

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 you start your vehicle. 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 you turn off traction control, 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 you allow the wheel(s) of one axle to spin
excessively while the StabiliTrak
®, ABS and brake
warning lights and the SERVICE STABILITRAK
message are displayed, you could damage the
transfer case. The repairs would not be covered by
your warranty. Reduce engine power and do not
spin the wheel(s) excessively while these lights and
this message 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, you may
notice a reduction in acceleration, or may hear a noise
or vibration. This is normal.
If your vehicle is in cruise control when the system
activates, the StabiliTrak
®light will ash and the cruise
control will automatically disengage. When road
conditions allow you to use cruise again, you may
re-engage the cruise control. SeeCruise Control on
page 3-13.
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, you should see your dealer/retailer for service.
4-8

Driving Uphill
Once you decide you can safely drive up the hill, you
need to take some special steps.
Use a low gear and get a rm grip on the steering
wheel.
Get a smooth start up the hill and try to maintain
your speed. Do not use more power than you
need, because you do not want the wheels to start
spinning or sliding.
{CAUTION:
Turning or driving across steep hills can be
dangerous. You could lose traction, slide
sideways, and possibly roll over. You could be
seriously injured or killed. When driving up
hills, always try to go straight up.
Try to drive straight up the hill if at all possible. If
the path twists and turns, you might want to nd
another route.
Ease up on your speed as you approach the top of
the hill.
Attach a ag to the vehicle to make you more visible
to approaching traffic on trails or hills.
Sound the horn as you approach the top of the hill to
let opposing traffic know you are there.
Use your headlamps even during the day. They
make your vehicle more visible to oncoming traffic.
{CAUTION:
Driving to the top (crest) of a hill at full speed
can cause an accident. There could be a
drop-off, embankment, cliff, or even another
vehicle. You could be seriously injured or
killed. As you near the top of a hill, slow down
and stay alert.
There are some things you should do if the vehicle stalls,
or is about to stall, and you cannot make it up the hill:
Push the brake pedal to stop the vehicle and keep it
from rolling backwards. Also, apply the parking
brake.
If your engine is still running, shift the transmission to
REVERSE (R), release the parking brake, and slowly
back down the hill in REVERSE (R).
4-19

If your engine has stopped running, you will need to
restart it. With the brake pedal pressed and the
parking brake still applied, shift the transmission to
PARK (P) and restart the engine. Then, shift to
REVERSE (R), release the parking brake, and slowly
back down the hill as straight as possible in
REVERSE (R).
As you are backing down the hill, put your left hand
on the steering wheel at the 12 o’clock position. This
way, you will be able to tell if your wheels are straight
and maneuver as you back down. It is best that you
back down the hill with your wheels straight rather
than in the left or right direction. Turning the wheel
too far to the left or right will increase the possibility
of a rollover.
There are also some things you must not do if you stall,
or are about to stall, when going up a hill:
Never attempt to prevent a stall by shifting into
NEUTRAL (N) to rev-up the engine and regain
forward momentum. This will not work. Your vehicle
will roll backwards very quickly and you could go
out of control.
Instead, apply the regular brake to stop the vehicle.
Then apply the parking brake. Shift to
REVERSE (R), release the parking brake, and
slowly back straight down.
{CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the
transmission is in PARK (P). This is because
the NEUTRAL position on the transfer case
overrides the transmission. You or someone
else could be injured. If you are going to leave
your vehicle, set the parking brake and shift
the transmission to PARK (P). But do not shift
the transfer case to NEUTRAL.
Never attempt to turn around if you are about to
stall when going up a hill. If the hill is steep
enough to stall your vehicle, it is steep enough to
cause you to roll over if you turn around. If you
cannot make it up the hill, you must back straight
down the hill.
If, after stalling, you try to back down the hill and decide
you just cannot do it, set the parking brake, put your
transmission in PARK (P) and turn off the engine. Leave
the vehicle and go get some help. Exit on the uphill side
and stay clear of the path the vehicle would take if it rolled
downhill. Do not shift the transfer case to NEUTRAL
when you leave the vehicle. Leave it in some gear.
4-20