2002 GMC ENVOY service

2-53
2. Press and hold the on/off button for six seconds.
Release the button when ªZONEº 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 find your zone
number, release the button. After about four seconds,
the mirror will return to the compass and
temperature display, and the new zone number will
be set.
Electrochromic Day/Night Rearview Mirror
with Compass, Temperature and OnStar

Your vehicle may have an automatic-dimming rearview
mirror with a compass, temperature display and the
OnStar system.
This is the on/off button.
There are three buttons for the OnStar system. See your
dealer for more information on the system and how to
subscribe to OnStar. See ªOnStar

Systemº in the Index
for more information about the services OnStar provides.

2-66
OnStar
System (If Equipped)
OnStar is a vehicle communications system that offers a
variety of services and provides a one
-touch hands-free
communication link between you and the OnStar Center.
To receive OnStar services, a service subscription
agreement is required and an additional fee may be
required. Services are available 24 hours a day, 7 days a
week. For more information, call 1
-888-ONSTAR-7
(1
-888-667-8277).
OnStar Services Button: Press this button once
to contact an advisor who will be able to assist you with
these services. If you are not quickly connected, the
system will automatically reset and redial. This ensures
connection to the center; there is no additional action
required. Press the Communication button to cancel
the automatic redial.
Emergency Button: In an emergency situation,
press the emergency service button. Upon receiving the
call, an advisor at the center will locate your vehicle and
assess the situation. If necessary, the advisor will alert
the nearest emergency service provider.
Communication Button: Press this button at
the end of a call. Also, press this button to answer a
call from the center, or cancel a call if one of the other
buttons is accidentally pressed. This button is also
used to access OnStar Personal Calling and Virtual
Advisor services. See the OnStar owner package for
more information.
Volume Control: You can control the volume of the
OnStar System using either the volume control knob
on the radio or using the steering wheel volume control
(if equipped).
Telltale Light: This light will indicate the status of
the system. A solid green light will come on when you
start the vehicle to let you know that the system is on
and is ready to make or receive calls.
If the light blinks green it means that an incoming or
outgoing call is in progress. Press the Communication
button if you notice the light blinking and you are not
on a call.

2-67
The light will be red in the event of an OnStar system
malfunction. If this occurs press the OnStar Services
button to attempt to contact an advisor. If the connection
is made, the advisor will assist you with steps to take to
make sure that the system is functioning properly. If you
cannot contact the advisor, take your vehicle to your
dealership as soon as possible for assistance.
Cellular Antenna
The cellular antenna on the outside of your vehicle is
critical to effective communications using the OnStar
system. Optimum cellular reception can be obtained
when the mast is straight up and down.
OnStar Services
The following services are available within OnStar
service plans. Your vehicle comes with a specific
one
-year service plan that allows use of some or all of
the following services.
Automatic Notification of Air Bag Deployment: If an
air bag deploys, a priority emergency signal is
automatically sent to the center. An advisor will locate
your vehicle's position, try to contact you and assist you
in the situation. If the center is unable to contact you, an
emergency service provider will be contacted.Stolen Vehicle Tracking: Call the center at
1
-888-4-ONSTAR (1-888-466-7827) to report your
vehicle stolen. The system can then attempt to locate
and track your vehicle and the advisor will assist the
proper authorities.
Roadside Assistance with Location: For vehicle
breakdowns, press the OnStar Services button. An
advisor will contact the appropriate help.
Remote Diagnostics: If an instrument panel light comes
on, press the OnStar Services button. An advisor can
perform a check of the engine on
-board computer, and
recommend what action needs to be taken.
OnStar MED
-NET: Med-Net can store your personal
medical history and provide it to emergency personnel if
necessary. (Requires activation and additional fee.)
Remote Door Unlock: To contact the center, call
1
-888-4-ONSTAR. You will be required to provide your
security information. An advisor will send a command
to your vehicle to unlock itself. The advisor can delay
unlocking your vehicle. Remote Door Unlock is
disabled 48 hours after the vehicle is parked to maintain
the battery charge.
Vehicle Locator Service: To contact the center, call
1
-888-4-ONSTAR. You will be required to provide your
security information. An advisor will send a command
to your vehicle to sound the horn and/or flash the lamps.

2-68
Route Support: An advisor can provide directions or
guidance to most places you want to go. In addition,
they can help you locate gas stations, rest areas, ATMs,
hospitals, hotels, stores, eateries and more.
Ride Assist: An advisor can locate transportation in the
event that you are unable to drive.
Concierge Services: The concierge advisor can obtain
tickets, reservations, or help with vacation/trip planning
and other unique items and services.
OnStar System Limitations
Complete limitations can be found on the Subscriber
Services Agreement. In order to provide you with
excellent service, calls with the OnStar Center may be
monitored or recorded.
OnStar Service is:

available in the 48 contiguous United States, Alaska,
Hawaii and Canada;

available when the vehicle is within the operating
range of a cellular provider;

subject to limitations caused by atmospheric
conditions, such as severe weather or topographical
conditions, such as mountainous terrain;

subject to cellular carrier equipment limitations.Global positioning locating capabilities will not be
available if satellite signals are obstructed.
OnStar will not function if the vehicle's battery is
discharged or disconnected. It may also be inoperative
if the vehicle is in an accident and the OnStar or vehicle
electrical system components are damaged.
OnStar is the communication link between you and
existing governmental emergency and roadside service
providers. OnStar will receive your call and use
reasonable effort to contact an appropriate provider.
OnStar cannot promise that the providers will respond
in a timely manner or at all.
Sunroof (Option)
Your vehicle may be equipped with a power sliding
sunroof. To open or close your sunroof, the ignition
or Retained Accessory Power (RAP) must be active.
See ªRetained Accessory Powerº in the Index.
Press and release the back of the button in the overhead
console to open the sunroof. You can press the front
of the button to close the sunroof. Once the sunroof is
closed, press the forward side of the button to open the
sunroof to the vent position.
The sunroof is also equipped with a sunshade which you
can pull forward to block sun rays.

2-69
HomeLink
Transmitter
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 modifications to this system by other than
an authorized service facility could void authorization to
use this equipment.
Programming the HomeLink Transmitter
Do not use the HomeLink Transmitter with any garage
door opener that does not have the ªstop and reverseº
feature. This includes any garage door opener model
manufactured before April 1, 1982.
Be sure that people and objects are clear of the garage
door you are programming.
It is recommended that a new battery be installed in
your hand
-held transmitter for quicker and more
accurate transmission of the radio frequency.
Your vehicle's engine should be turned off while
programming the transmitter. Follow these steps to
program up to three channels:
1. Decide which one of the three channels (one of the
HomeLink buttons) you want to program.
2. Press and hold the desired button on HomeLink
through Step 3.

2-77
Air Bag Readiness Light
There is an air bag readiness light on the instrument
panel, 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 wiring and the crash sensing and
diagnostic module. For more information on the air bag
system, see ªAir Bagº in the Index.
This light will come on
when you start your vehicle,
and it will flash 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.
CAUTION:
If the air bag readiness light stays on after you
start your vehicle, it means the air bag system
may not be working properly. The air bags in
your vehicle may not inflate in a crash, or they
could even inflate without a crash. To help avoid
injury to yourself or others, have your vehicle
serviced right away if the air bag readiness light
stays on after you start your vehicle.
The air bag readiness light should flash for a few
seconds when you turn the ignition key to RUN. If the
light doesn't come on then, have it fixed so it will be
ready to warn you if there is a problem.

2-79
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.Brake System Warning Light
When the ignition is on, the brake system warning light
will come on when you set your parking brake. The light
will stay on if your parking brake doesn't release fully.
If it stays on after your parking brake is fully released, it
means you have a brake problem.
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, there could be a brake
problem. Have your brake system inspected right away.

2-80
United States Canada
This light should come on briefly when you turn the
ignition key to RUN. If it doesn't come on then, have it
fixed 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 floor.
It may take longer to stop. If the light is still on, have the
vehicle towed for service. See ªTowing Your Vehicleº in
the Index.
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've
pulled off the road and stopped carefully, have
the vehicle towed for service.