service GMC YUKON XL 2006 User Guide

If the SERVICE 4WD message stays on, you should
take your vehicle to your dealer for service. See “Service
4WD message” underDIC Warnings and Messages
on page 3-56.
Shifting Into Four-Wheel High or
AUTO 4WD (Automatic Four-Wheel Drive)
Press and release the Four-Wheel High or AUTO
4WD button. This can be done at any speed, except
when shifting from Four-Wheel Low, and the indicator
light will ash while shifting. It will remain on when
the shift is completed.
Shifting Into Two-Wheel High
Press and release the Two-Wheel High button.
This can be done at any speed, except when
shifting from Four-Wheel Low.
Shifting Into Four-Wheel Low
To shift to the Four-Wheel Low position, the ignition
must be in RUN and the vehicle must be stopped
or moving less than 3 mph (5 km/h) with the
transmission in NEUTRAL (N). The preferred
method for shifting into four-wheel low is to have
your vehicle moving 1 to 2 mph (1.6 to 3.2 km/h).Press and release the Four-Wheel Low button.
You must wait for the four-wheel low indicator light
to stop ashing and remain on before shifting your
transmission in gear.
Notice:Shifting the transmission into gear before
the Four-Wheel Low indicator light has stopped
ashing could damage the transfer case. To
help avoid damaging your vehicle, always wait for
the Four-Wheel Low indicator light to stop ashing
before shifting the transmission into gear.
It is typical for your vehicle to exhibit signicant
engagement noise and bump when shifting between
Four-Wheel Low and Four-Wheel High ranges or from
NEUTRAL with the engine running.
If the Four-Wheel Low button is pressed when your
vehicle is in gear and/or moving, the Four-Wheel Low
indicator light will ash for 30 seconds and not complete
the shift unless your vehicle is moving less than
3 mph (5 km/h) and the transmission is in NEUTRAL (N).
After 30 seconds the transfer case will shift to
Four-Wheel High mode.
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{CAUTION:
Four-wheel drive vehicles with the transfer
case in NEUTRAL will allow the vehicle to roll,
even if your shift lever is in PARK (P). So, be
sure the transfer case is in a drive gear — not
in NEUTRAL. Always set your parking brake.
Follow the proper steps to be sure your vehicle will
not move. SeeShifting Into Park (P) on page 2-32.
If you are pulling a trailer, seeTowing a Trailer
on page 4-60.
Mirrors
Manual Rearview Mirror
Pull the tab under the mirror toward you to reduce glare
from headlamps behind you after dark. Push the tab
away from you for normal daytime operation.
Automatic Dimming Rearview Mirror
with OnStar
®and Compass
Your vehicle may have an automatic-dimming rearview
mirror with a compass and the OnStar®system.
There are three additional buttons for the OnStar
®
system. See your dealer for more information on
the system and how to subscribe to OnStar®.
SeeOnStar®System on page 2-50for more
information about the services OnStar®provides.
2-37

To adjust for compass variance, do the following:
1. Find your current location and variance zone
number on the map.
2. Press and hold the on/off button for six seconds.
Release the button when ZONE is displayed.
The number shown is the current zone number.3. Scroll through the zone numbers that appear in
the compass/temperature window on the mirror
by pressing the on/off button. Once you nd your
zone number, release the button. After about
four seconds, the mirror will return to the compass
display, and the new zone number will be set.
Automatic Dimming Rearview Mirror
with OnStar
®, Compass and
Temperature Display
Your vehicle may have this feature. When on, the
automatic dimming mirror dims to the proper level to
minimize glare from lights behind you after dark.
The mirror has a dual display in the upper right corner
of the mirror face that shows the compass reading
and the outside temperature.
Control buttons for the OnStar
®system are at the
bottom of the mirror. SeeOnStar®System on page 2-50
for more information about the services OnStar®
provides.
P(On/Off):This is the on/off button.
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OnStar®System
OnStar®uses global positioning system (GPS) satellite
technology, wireless communications, and live advisors
to provide you with a wide range of safety, security,
information, and convenience services. If your airbags
deploy, the system is designed to make an automatic call
to OnStar
®Emergency where we can request emergency
services be sent to your location. If you lock your keys in
the car, call OnStar
®at 1-888-4-ONSTAR and they can
send a signal to unlock your doors. if you need roadside
assistance, press the OnStar
®button and they will get
you the help you need.
A complete OnStar
®User’s Guide and the Terms
and Conditions of the OnStar®Subscription Service
Agreement are included in the vehicle’s glove box
literature. For more information, visit www.onstar.com or
www.onstar.ca. Contact OnStar
®at 1-888-4-ONSTAR
(1-888-466-7827), or press the OnStar®button to speak
to an OnStar®advisor 24 hours a day, 7 days a week.Terms and conditions of the Subscription Service
Agreement can be found at www.onstar.com or
www.onstar.ca.
OnStar®Services
For new vehicles equipped with OnStar®, the Safe
and Sound plan is included for one year from the date
of purchase. The OnStar
®subscription can be extended
beyond the rst year, or upgraded to the Directions
and Connections
®Plan to meet your needs. For more
information, press the OnStar®button to speak with
an advisor.
Safe and Sound Plan

Automatic Notication of Airbag Deployment
Emergency Services
Roadside Assistance
Stolen Vehicle Tracking
AccidentAssist
Remote Door Unlock/Vehicle Alert
Remote Diagnostics
Online Concierge
2-50

Directions and Connections®Plan
All Safe and Sound Plan Services
Driving Directions
RideAssist
Information and Convenience Services
OnStar®Personal Calling
As an OnStar®subscriber, the Personal Calling
capability allows you to make hands-free calls using
a wireless system that is integrated into the vehicle.
Calls can be placed nationwide using simple voice
commands with no additional contracts and no additional
roaming charges. To nd out more about OnStar
®
Personal Calling, refer to the OnStar®User’s Guide
in the vehicle’s glove box, visit www.onstar.com
or www.onstar.ca, or speak to an OnStar
®advisor
by pressing the OnStar®button or calling
1-888-4-ONSTAR (1-888-466-7827).
OnStar®Virtual Advisor
Your vehicle may have Virtual Advisor. It is a feature
of OnStar®Personal Calling that uses your minutes
to access weather, local traffic reports and stock quotes.
By pressing the phone button and giving a few simple
voice commands, you can browse through the
various topics. Customize your information prole at
www.myonstar.com. See the OnStar
®user’s guide
for more information.
OnStar®Steering Wheel Controls
Your vehicle may be
equipped with a Talk/Mute
button that can be used
to interact with OnStar
®.
SeeAudio Steering Wheel
Controls on page 3-132
for more information.
When calling into voice mail systems or to dial directory
numbers, press this button once, wait for the response,
say the number(s) to be dialed, wait for the number(s)
to be repeated and then say “dial.”
See the OnStar
®user’s guide for more information.
2-51

Universal Home Remote
System
The Universal Home Remote System, 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.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 received,
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.
2-52

Auxiliary Roof Mounted Lamp
If your vehicle has this feature, this button includes
wiring provisions for a dealer or a qualied service
center to install an auxiliary roof lamp.
This button is located on
the center of the instrument
panel near the climate
controls.
When the wiring is connected to an auxiliary roof
mounted lamp, pressing the button will activate the lamp
and illuminate an indicator light near the button. Pressing
the button again will turn off the roof mounted lamp.
If your vehicle has this button, your vehicle may have the
snow plow prep package. For further information see
Adding a Snow Plow or Similar Equipment on page 4-51.
Instrument Panel Brightness
D(Instrument Panel Brightness):This feature
controls the brightness of the instrument panel lights.
The thumbwheel for this feature is located next to
the headlamp control.
Turn the thumbwheel up to adjust the instrument panel
lights. Turn the thumbwheel up to return the radio
display to full brightness when the headlamps or parking
lamps are on. To turn on the dome lamps, turn the
thumbwheel all the way up.
Dome Lamps
The dome lamps will come on when you open a door.
You can also turn the dome lamps on by turning
the thumbwheel, located next to the exterior lamps
control, all the way up. In this position, the dome lamps
will remain on whether a door is opened or closed.
3-19

Airbag Readiness Light
There is an airbag readiness light on the instrument
panel cluster, which shows the airbag symbol. The
system checks the airbag’s electrical system for
malfunctions. The light tells you if there is an electrical
problem. The system check includes the airbag
sensors, the airbag modules, the passenger sensing
system (if equipped), the wiring and the crash sensing
and diagnostic module. For more information on the
airbag system, seeAirbag System on page 1-74.
This light will come on
when you start your
vehicle, and it will ash for
a few seconds. This means
the system is ready.
If the airbag readiness light stays on after you start the
vehicle or comes on when you are driving, your airbag
system may not work properly. Have your vehicle
serviced right away.
Passenger Airbag Status Indicator
If your vehicle has a passenger sensing system,
your rearview mirror will have a passenger airbag status
indicator.
When the ignition key is turned to RUN or START,
the passenger airbag 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,
Passenger Airbag Status Indicator – United States
Passenger Airbag Status Indicator – Canada
3-38

If the word OFF or the off symbol is lit on the airbag
status indicator, it means that the passenger sensing
system has turned off the right front passenger’s frontal
airbag. 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 airbag readiness light
ever come on together, it means that something
may be wrong with the airbag 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 airbag. SeeAirbag
Readiness Light on page 3-38.
Battery Warning Light
If this light is displayed
when the engine is
running, you may have
a problem with your
charging system.
The battery display will also stay on while the key is in
RUN until the engine is started.
If the light stays on after starting the engine it could
indicate a problem with the generator drive belt, or some
other charging system problem. Have it checked right
away. Driving with this light displayed could drain
your battery.
If you must drive a short distance with this light
displayed, it helps to turn off all your accessories, such
as the radio and the air conditioner.
3-40

Voltmeter Gage
When your engine is not
running, but the ignition
is in RUN, this gage shows
your battery’s state of
charge in DC volts.
When the engine is running, the gage shows the
condition of the charging system. The gage may
transition from a higher to lower or a lower to higher
reading, this is normal. Readings between the low
and high warning zones indicate the normal
operating range.Readings in the low warning zone may occur when a
large number of electrical accessories are operating in
the vehicle and the engine is left at an idle for an
extended period. This condition is normal since the
charging system is not able to provide full power
at engine idle. As engine speeds are increased, this
condition should correct itself as higher engine speeds
allow the charging system to create maximum power.
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.
3-41