2002 GMC SIERRA service

2-16
Ignition Positions
With your key in the ignition switch you can turn it to
five different positions.
ACCESSORY (A): This position lets you use
things like the radio, power windows and the windshield
wipers when the engine is off. Push in the key and
turn it toward you.
NOTICE:
If your key seems stuck in LOCK and you can't
turn it, be sure you are using the correct key;
if so, is it all the way in? Turn the key only with
your hand. Using a tool to force it could break
the key or the ignition switch. If none of this
works, then your vehicle needs service.
LOCK (B): This position locks your ignition and
transmission. It's a theft
-deterrent feature. You will only
be able to remove your key when the ignition is turned
to LOCK.
OFF (C): This position lets you turn off the engine.
Use OFF if you must have your vehicle in motion while the
engine is off (for example, if your vehicle is being pushed).
RUN (D): This position is for driving.
START (E): This position starts your engine.
Retained Accessory Power (RAP)
The Retained Accessory Power (RAP) feature will allow
certain features on your vehicle to continue to work up
to 20 minutes after the ignition key is turned to OFF.

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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 if equipped, the steering wheel
volume controls.
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.

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The light will be red in the event of an OnStar system
malfunction. If this occurs press the OnStar 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 communication
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 sent
automatically 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 an additional fee.)
Accident Assist: An advisor can provide step
-by-step
guidance following an accident.
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.

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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.
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.

2-57
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.
3. When the HomeLink indicator light begins to blink
slowly (this may take up to 30 seconds), hold the
hand
-held transmitter about 1 to 3 inches (3 to 8 cm)
away from HomeLink and then press and hold the
transmit button on the hand
-held transmitter.
Continue to hold both buttons until the indicator
light on HomeLink begins to flash rapidly
(this may take up to 90 seconds).

2-65 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, the passenger air bag
suppression circuit 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.

2-67
CAUTION:
If the air bag readiness light ever comes on when
you have turned off the air bag, it means that
something may be wrong with the air bag system.
The right front passenger's air bag could inflate
even though the switch is off.
If this ever happens, don't let anyone whom the
national government has identified as a member
of a passenger air bag risk group sit in the right
front passenger's position (for example, don't
secure a rear
-facing child restraint in the right
front passenger's seat) until you have your
vehicle serviced.
Voltmeter
United States Canada
When your engine is not running, but the ignition is in
RUN, this gage shows your battery's state of charge in
DC volts.

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When the engine is running, the gage shows the
condition of the charging system. 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 idle
speed. 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
With the ignition on, the brake system warning light will
flash when you set the parking brake. The light will
flash 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, there could be a brake
problem. Have your brake system inspected right away.
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.