service GMC YUKON 2004 User Guide

G(4HI):Use the 4HI position when you need extra
traction, such as on snowy or icy roads or in most
off-road situations. This setting also engages your front
axle to help drive your vehicle. This is the best setting
to use when plowing snow.
5(4LO):This setting also engages your front axle
and delivers extra torque. You may never need this
setting. It sends maximum power to all four wheels. You
might choose 4LO if you are driving off-road in deep
sand, deep mud, deep snow and climbing or descending
steep hills.
{CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the
transmission is in PARK (P). You or someone
else could be seriously injured. Be sure to set
the parking brake before placing the transfer
case in NEUTRAL. SeeParking Brake on
page 2-37.NEUTRAL (N):Shift the vehicle’s transfer case to
NEUTRAL only when towing your vehicle. See
Recreational Vehicle Towing on page 4-53orTowing
Your Vehicle on page 4-53for more information.
Indicator lights in the button show which setting you are
in. The indicator lights will come on briey when you
turn on the ignition and one will stay on. If the lights do
not come on, you should take your vehicle to your
dealer for service. An indicator light will ash while
shifting the transfer case. It will remain illuminated when
the shift is complete. If for some reason the transfer
case cannot make a requested shift, it will return to the
last chosen setting.
If the SERVICE 4WD message stays on, you should
take your vehicle to your dealer for service. See″Service
4WD message″underDriver Information Center (DIC)
on page 3-58.
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You can choose among three driving settings:
d(Stabilitrak®):This button is used with the
Stabilitrak®system and is also used to shift the transfer
case into Neutral (N). For more information on using
Stabilitrak
®seeStabilitrak®System on page 4-11.
f(All-Wheel Drive):This setting delivers power to
all four wheels as needed depending on road and driving
conditions.
g(4LO):This setting delivers extra torque. You may
never need this setting. It sends maximum power to
all four wheels. You might choose 4LO if you are driving
off-road in deep sand, deep mud, deep snow and
climbing or descending steep hills.
{CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the
transmission is in PARK (P). You or someone
else could be seriously injured. Be sure to set
the parking brake before placing the transfer
case in NEUTRAL. SeeParking Brake on
page 2-37.NEUTRAL:Shift the vehicle’s transfer case to
NEUTRAL only when towing your vehicle. See
Recreational Vehicle Towing on page 4-53orTowing
Your Vehicle on page 4-53for more information.
Indicator lights in the buttons show which setting you
are in. The indicator lights will come on briey when you
turn on the ignition and one will stay on. If the lights
do not come on, you should take your vehicle to your
dealer for service. An indicator light will ash while
shifting the transfer case. It will remain illuminated when
the shift is complete. If for some reason the transfer
case cannot make a requested shift, it will return to the
last chosen setting.
If the SERVICE 4WD message stays on, you should
take your vehicle to your dealer for service. See
SERVICE 4WD underDriver Information Center (DIC)
on page 3-58.
2-34

OnStar®System
OnStar®uses global positioning system (GPS) satellite
technology, wireless communications, and state of
the art call centers to provide you with a wide range of
safety, security, information and convenience services.
A complete OnStar
®user’s guide and the terms
and conditions of the OnStar®Subscription Service
Agreement are included in your OnStar®-equipped
vehicle’s glove box literature. For more information, visit
www.onstar.com, contact OnStar
®at 1−888−4−ONSTAR
(1−888−466−7827), or press the blue OnStar®button
to speak to an OnStar®advisor 24 hours a day, 7 days
a week.
A completed Subscription Service Agreement is required
prior to delivery of OnStar
®services and prepaid
calling minutes are also required for OnStar®Personal
Calling and OnStar®Virtual Advisor use. Terms and
conditions of the Subscription Service Agreement can be
found at www.onstar.com.
OnStar®Services
One of the following plans is normally included for a
specic duration with each vehicle equipped with
OnStar
®. You can upgrade or extend your OnStar®
service plan to meet your needs.
Safe and Sound Plan

Automatic Notication of Air Bag Deployment
Emergency Services
Roadside Assistance
Stolen Vehicle Assistance
AccidentAssist
Remote Door Unlock
Remote Diagnostics
Online Concierge
Directions and Connections Plan

All Safe and Sound Plan services
Route Support
RideAssist
Information and Convenience Services
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Luxury and Leisure Plan

All Directions and Connections Plan services
Personal Concierge
OnStar®Personal Calling
With OnStar®Personal Calling, you have a safer way to
stay connected while driving. It’s a hands-free wireless
phone that’s integrated into your vehicle. You can place
calls nationwide using voice-activated dialing with no
contracts and no additional roaming charges. To nd out
more about OnStar
®Personal Calling, refer to the
OnStar®owner’s guide in your vehicle’s glove box, or
call OnStar®at 1−888−4−ONSTAR (1−888−466−7827).
OnStar®Virtual Advisor
With OnStar®Virtual Advisor you can listen to your
favorite news, entertainment and information topics,
such as traffic and weather reports, stock quotes
and sports scores. You listen to your e-mail through
your vehicle’s speakers, and reply with your hands on
the wheel and your eyes on the road.
OnStar®Steering Wheel Controls
g
: If your vehicle is
equipped with the steering
wheel control buttons
you can use them
to interact with the OnStar
®
system.
See the OnStar
®manual provided with your vehicle for
more information.
2-54

HomeLink®Transmitter
HomeLink®a combined universal transmitter and
receiver, provides a way to replace up to three
hand-held transmitters used to activate devices such as
gate operators, garage door openers, entry door
locks, security systems and home lighting. Additional
HomeLink
®information can be found on the internet at
www.homelink.com or by calling 1-800-355-3515.This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
(1) this device may not cause harmful interference, and
(2) this device must accept any interference received,
including interference that may cause undesired
operation.
This device complies with RSS-210 of Industry Canada.
Operation is subject to the following two conditions:
(1) this device may not cause interference, and (2) this
device must accept any interference, including
interference that may cause undesired operation of the
device.
Changes and modications to this system by other than
an authorized service facility could void authorization
to use this equipment.
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Fog Lamps
If your vehicle has fog lamps, use them for better vision
in foggy or misty conditions.
The fog lamp button is
located on the left side of
the instrument panel.
Your parking lamps and/or low-beam headlamps must
be on for your fog lamps to work.
Press the button to turn the fog lamps on. Press the
button again to turn them off. An indicator light will glow
in the button when the fog lamps are on.
Remember, fog lamps alone will not give off as much
light as your headlamps. Never use your fog lamps
in the dark without turning on your headlamps.
The fog lamps will go off whenever your high-beam
headlamps come on. When the high beams go off, the
fog lamps will come on again.The fog lamps will be cancelled after the ignition is
turned off. If you still want to use the fog lamps after you
restart the vehicle, you will need to press the fog
lamp button again.
Auxiliary Roof Mounted Lamp Switch
If your vehicle has this feature, this switch includes
wiring provisions for a dealer or a qualied service
center to install an auxiliary roof lamp.
This switch is located on
the center of the
instrument panel near the
comfort controls.
When the switch wiring is connected to an auxiliary roof
mounted lamp, pressing the switch will activate the lamp
and illuminate an indicator light near the switch. Pressing
the switch again will turn off the roof mounted lamp.
3-18

Air Bag Readiness Light
There is an air bag readiness light on the instrument
panel cluster, which shows the air bag symbol.
The system checks the air bag’s electrical system for
malfunctions. The light tells you if there is an electrical
problem. The system check includes the air bag
sensors, the air bag modules, the passenger sensing
system (if equipped), the wiring and the crash sensing
and diagnostic module. For more information on the
air bag system, seeAir Bag Systems on page 1-72.
This light will come on
when you start your
vehicle, and it will ash for
a few seconds. Then the
light should go out. This
means the system is ready.
If the air bag readiness light stays on after you start the
vehicle or comes on when you are driving, your air
bag system may not work properly. Have your vehicle
serviced right away.
Passenger Air Bag Status Indicator
If your vehicle has the passenger sensing system
your rearview mirror will have a passenger air bag status
indicator.
When the ignition key is turned to RUN or START, the
passenger air bag status indicator will light ON and
OFF, or the symbol for on and off, for several seconds
as a system check. Then, after several more seconds,
the status indicator will light either ON or OFF, or either
the on or off symbol to let you know the status of the
right front passenger’s frontal air bag.
Passenger Air Bag Status Indicator – United States
Passenger Air
Bag Status
Indicator – Canada
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If the word ON or the on symbol is lit on the passenger
air bag status indicator, it means that the right front
passenger’s frontal air bag is enabled (may inate).
{CAUTION:
If the on indicator comes on when you have a
rear-facing child restraint installed in the right
front passenger’s seat, it means that the
passenger sensing system has not turned off
the passenger’s frontal air bag. A child in a
rear-facing child restraint can be seriously
injured or killed if the right front passenger’s
air bag inates. This is because the back of
the rear-facing child restraint would be very
close to the inating air bag. Don’t use a
rear-facing child restraint in the right front
passenger’s seat unless the air bag has been
turned off.If the word OFF or the off symbol is lit on the air bag
status indicator, it means that the passenger sensing
system has turned off the right front passenger’s frontal
air bag. SeePassenger Sensing System on page 1-82
for more on this, including important safety information.
If, after several seconds, all status indicator lights
remain on, or if there are no lights at all, there may be a
problem with the lights or the passenger sensing
system. See your dealer for service.
{CAUTION:
If the off indicator and the air bag readiness
light ever come on together, it means that
something may be wrong with the air bag
system. If this ever happens, have the vehicle
serviced promptly, because an adult-size
person sitting in the right front passenger seat
may not have the protection of the frontal air
bag. See “Air Bag Readiness Light” in the Index.
3-44

You can only drive for a short time with the reading in
either warning zone. If you must drive, turn off all
unnecessary accessories.
Readings in either warning zone indicate a possible
problem in the electrical system. Have the vehicle
serviced as soon as possible.
Brake System Warning Light
With the ignition on, the brake system warning light will
ash when you set the parking brake. The light will
ash if the parking brake doesn’t release fully. If you try
to drive with the parking brake engaged, a chime will
sound when the vehicle speed is greater than 3 mph
(5 km/h).
Your vehicle’s hydraulic brake system is divided into two
parts. If one part isn’t working, the other part can still
work and stop you. For good braking, though, you need
both parts working well.
If the warning light comes on and a chime sounds there
could be a brake problem. Have your brake system
inspected right away.This light should come on briey when you turn the
ignition key to RUN. If it doesn’t come on then, have it
xed so it will be ready to warn you if there’s a
problem.
If the light comes on while you are driving, pull off the
road and stop carefully. You may notice that the pedal is
harder to push. Or, the pedal may go closer to the
oor. It may take longer to stop. If the light is still on,
have the vehicle towed for service. SeeTowing
Your Vehicle on page 4-53. United States
Canada
3-46

{CAUTION:
Your brake system may not be working
properly if the brake system warning light is
on. Driving with the brake system warning light
on can lead to an accident. If the light is still
on after you have pulled off the road and
stopped carefully, have the vehicle towed for
service.
Anti-Lock Brake System Warning
Light
With the anti-lock brake
system, this light will come
on when you start your
engine and may stay on for
several seconds.
That’s normal. If the light doesn’t come on then, have it
xed so it will be ready to warn you if there is a problem.
If the light stays on, or comes on when you’re driving,
your vehicle needs service. You will also hear a chime
sound when the light is on steady. If the regular brake
system warning light isn’t on, you still have brakes, but
you don’t have anti-lock brakes. If the regular brake
system warning light is also on you don’t have anti-lock
brakes and there’s a problem with your regular brakes. In
addition to both lights, you will also hear a chime sound
on the rst occurrence of a problem and each time the
vehicle is shut off and then restarted. SeeBrake System
Warning Light on page 3-46.
3-47