Part 1

OnStar Description and Operation

This OnStar(R) system consists of the following components:

* Telematics Communication Interface Module
* OnStar(R) button assembly
* Microphone
* Cellular antenna
* Navigation antenna
* Bluetooth (R) antenna (If Equipped)
* Back Up Battery (If Equipped)

This system also interfaces with the factory installed vehicle audio system.

Telematics Communication Interface Module

The telematics communication interface module is a cellular device that allows the user to communicate data and voice signals over the national cellular network. Power is provided by a dedicated, fused B+ circuit. Ground is provided through the vehicle wiring harness attached to the module. The ignition state is determined by the telematics communication interface module through serial data messaging.

Dedicated circuits are used to connect the telematics communication interface module to a microphone, the button assembly, and to command the status LED. The telematics communication interface module communicates with the rest of the vehicle over the serial data bus.

The module houses 2 technology systems, one to process GPS data, and another for cellular information. The cellular system connects the OnStar(R) system to the cellular carrier's communication system by interacting with the national cellular infrastructure. The module sends and receives all cellular communications over the cellular antenna and cellular antenna coax. GPS satellites orbiting earth are constantly transmitting signals of their current location. The OnStar(R) system uses the GPS signals to provide location on demand.

The module also has the capability of activating the horn, initiating door lock/unlock, slowing down stolen vehicle gradually, or activating the exterior lamps using the serial data circuits. These functions can be commanded by the OnStar(R) Call Center per a customer request.

OnStar(R) Button Assembly

The OnStar(R) button assembly may be part of the rearview mirror, or a separate, stand alone unit. The button assembly is comprised of 3 buttons and a status LED. The buttons are defined as follows:

* The answer/end call button, which is black with a white phone icon, allows the user to answer and end calls or initiate speech recognition.
* The blue OnStar(R) call center button, which displays the OnStar(R) logo, allows the user to connect to the OnStar(R) call center.
* The emergency button, which displays a white cross with a red background, sends a high priority emergency call to the OnStar(R) call center when pressed.

The telematics communication interface module supplies 10 volts to the OnStar(R) button assembly on the keypad supply voltage circuit. When pressed, each button completes a circuit across a resistor allowing a specific voltage to be returned to the telematics communication interface module on the keypad signal circuit. Depending upon the voltage range returned the telematics communication interface module is able to identify which button has been pressed.

The OnStar(R) status LED is located with the button assembly. The LED is green when the system is ON and operating normally. When the status LED is green and flashing, it is an indication that a call is in progress. When the LED is red, this indicates a system malfunction is present. In the event there is a system malfunction and the OnStar(R) system is still able to make a call, the LED will flash red during the call.

If the LED does not illuminate, this may indicate that the customers OnStar(R) subscription is not active or has expired. Push the blue OnStar button to connect to an advisor who can then verify the account status.

Each LED is controlled by the telematics communication interface module over dedicated LED signal circuits. Ground for the LED is provided by the wiring harness attached to the button assembly.

Secondary OnStar(R) Controls

Some vehicles may have an additional button that when pushed can engage the OnStar(R) system. The button may be a symbol of a face with sound waves, or may say MUTE, or be a symbol of a radio speaker with a slash through it.

By engaging the OnStar(R) system with this feature, the user can interact with the system by use of voice commands. A complete list of these commands is supplied in the information provided to the customer. If the information is not available for reference, at any command prompt the user can say "HELP" and the telematics communication interface module will return an audible list of available commands.

OnStar(R) Microphone

The OnStar(R), or cellular phone microphone, can be a part of the rearview mirror assembly, or on some vehicle lines, a separate, stand alone unit. In either case, the telematics communication interface module supplies approximately 10 V to the microphone on the cellular phone microphone signal circuit, and voice data from the user is sent back to the telematics communication interface module over the same circuit. A cellular phone microphone low reference circuit or a drain wire provides a ground for the microphone.

Cellular and GPS Antennas

This vehicle will be equipped with one of the following types of antennas:

* Separate, standalone cellular and navigation antennas
* A combination cellular and navigation antenna, which brings the functions of both into a single part
* A cellular, GPS, and digital radio receiver antenna, which also incorporates the functionality of the digital radio receiver satellite antenna (XM).
* A cellular, GPS, and digital radio receiver antenna, which also incorporates the AM/FM antenna.

The cellular antenna is the component that allows the OnStar(R) system to send and receive data over airwaves by means of cellular technology. The antenna is connected at the base to a coax cable that plugs directly into the telematics communication interface module.

The GPS antenna is used to collect the signals of the orbiting GPS satellites. Within the antenna is housed a low noise amplifier that allows for a more broad and precise reception of this data. The antenna is connected at the base to a coax cable that plugs directly into the telematics communication interface module. The cable also provides a path for DC current for powering the antenna.

The OnStar(R) Call Center also has the capability of communicating with the vehicle during an OnStar(R) call to retrieve the latest GPS location and transmit it to the OnStar(R) Call Center. A history location of the last recorded position of the vehicle is stored in the module and marked as aged, for as long as the module power is not removed. Actual GPS location may take up to 10 minutes to register in the event of a loss of power.

Cellular and Navigation Signal Antenna Splitter

The navigation signal splitter is a component for dividing the navigation signal antenna signal into two paths without any transmission loss. It has two RF-connectors, one signal fakra connector and one double fakra connector. Port 1 is the input for connecting to the navigation signal antenna, port 2 is the output for the car OnStar navigation system, port 3 is the output for the navigation radio. Port 1 and 2 are galvanically coupled internally using a matching network. The OnStar system supplies the navigation signal antenna with power via port 2. Connectivity is made between port 1 and 3 though and internal coupling element and low noise amplifier. The navigation radio provides the amplifier with power via port 3.

Bluetooth (R) (If Equipped)

Bluetooth (R) wireless technology is a short-range communications technology intended to replace the cables connecting portable and/or fixed devices while maintaining high levels of security. Only vehicles with steering wheel controls will have Bluetooth (R) functionality. In order to utilize the vehicle Bluetooth (R) system, a Bluetooth (R) equipped cellular phone is required.

The Bluetooth (R) antenna is a small fixed antenna connected directly to the telematics communication interface module and is used to send and receive signals from a Bluetooth (R) enabled cellular phone. The antenna utilizes no cabling and is not external to the vehicle. The available features and functions are determined by the software within the device being used and the telematics communication interface module. The operating range of the signal from the vehicle is approximately 30 feet. Note that the operating range is dependent upon the cellular phone being used and battery level of the phone.

With Bluetooth (R) technology customers can experience hands-free calling as their Bluetooth (R) capable cellular phones are wirelessly connected to the vehicle. It will allow customers to place and receive calls using the steering wheel controls and voice recognition. The vehicle audio system will allow you to listen to your call through the vehicle speakers and adjust volume through steering wheel or radio controls.

Not all Bluetooth (R) cellular phones are guaranteed to work with the vehicle's Bluetooth (R) system. Based on the cellular phone's service provider and the manufacturer's implementation of Bluetooth (R), not all phones support all available Bluetooth (R) functionality. Bluetooth (R) enabled cellular phones will be tested for vehicle compatibility and a feature compatibility list will be provided via the GM Bluetooth (R) website: http://www.gm.com/vc/bluetooth/

Bluetooth (R) Features Supported

The following is a list of features supported by the Bluetooth (R) system. Note that not all devices will support all of the listed functions.

* Automatic reconnection - highest priority phone will automatically be connected to vehicle when vehicle ignition is on
* Hands-free dialing- via digits, redial, name tags (phone number saved to a nametag via voice recognition)
* Answering a call
* Ending a call
* Mute a Call
* Rejecting a call - ignore an incoming call
* Call Waiting
* Three-way Calling - initiated from hands-free system
* Send Number During a Call - this is used when calling a menu-driven phone system
* Transfer a Call - transfer call from vehicle to cellular phone and visa versa
* Voice Pass-Thru - allow access to the voice recognition commands on the cellular phone

Pairing a Bluetooth (R) Cellular Phone to the Vehicle

In order to use hands-free calling, the cellular phone must be paired to the vehicle. Up to five devices can be paired to the vehicle at one time, but only one can be connected at any given time. To pair a phone, the customer must know how to operate the Bluetooth (R) functionality of their phone. The pairing process must only be done one time for each phone, unless that phone's information is deleted. For safety reasons, the pairing process is disabled while the vehicle is moving.

Once the Bluetooth (R) cellular phone has been paired with vehicle, it will automatically connect to the vehicle when the ignition is on and the device is on. When more than one paired phone is in the vehicle, the phone with the highest priority will be connected. If the cellular phone is in use while getting into the vehicle, the phone can be switched to hands-free mode with the press of a button. In addition, a call in progress can be transferred from the vehicle hands-free mode to the phone to continue the call as the customer exits the vehicle.

Complete pairing instructions are provided in the Vehicle Owners Manual.

Back-up Battery (If Equipped)

Note: Do not disconnect the main vehicle battery or remove the telematics communication interface control module fuse with the ignition key in any position other than OFF. Disconnecting power to the telematics communication interface control module in any way while the ignition is ON or with retained accessory power activated may cause activation of the OnStar(R) Back-Up Battery. This action is per design as the back-up battery is designed to provide power to the telematics communication interface module so an emergency notification call can be made after a vehicle collision where the main battery is disabled. Once the Back-Up Battery is activated it will stay on until it has completely discharged. The back-up battery is not rechargeable and once activated the back-up battery must be replaced.

Certain OnStar(R) equipped vehicles may also be equipped with a back-up battery. The back-up battery is a non-rechargeable, lithium battery intended to provide an auxiliary power source for the telematics communication interface module in the event of a vehicle collision where power from the main vehicle battery is lost.

The back-up battery is intended to have a limited life span of approximately 4 years and is designed to maintain an open circuit voltage between 16V and 9V throughout this period. This allows the battery to power the basic functions of the telematics communication interface module for least one 200 second (5 minute) call at the end of the 4 year span, should a main vehicle battery loss collision occur.

The back-up battery is connected to the telematics communication interface module through the back-up battery positive voltage circuit and back-up battery ground circuit and is protected from a short circuit by means of an internal fuse. In the event the back-up battery positive voltage circuit is shorted to the back-up battery ground circuit or chassis ground, the fuse will open and render the back-up battery permanently inoperable. The status of the back-up battery and its associated wiring is monitored by the telematics communication interface module.