Circuit/System Description
Each of the audio output channel circuits (+) and (-), at the radio and audio amplifier have a DC bias voltage that is one half of the battery voltage. When using a DMM, each of the audio output channel circuits will measure approximately 6.5V DC. The audio being played on the system is produced by a varying AC voltage that is centered around the DC bias voltage on the same circuit. The AC voltage is what causes the speaker cone to move and produce sound. This voltage will vary depending on what type of audio is being listened to, talk or music, and type of music, as well as the volume setting of the system. Low volume and talk settings will measure around 1V AC and less, where constant music may measure 3V AC and slightly higher. In an amplified audio system, these similar AC voltage measurements may be slightly higher on the output of the amplifier, and the typical AC voltage readings at the output of the radio are less than 1V AC.
The digital radio receiver (DRR) receives digital radio information from a specific digital radio antenna located on the outside of the vehicle. The DRR is connected to the digital radio antenna via a shielded coaxial cable. The antenna cable also provides a path for DC current for powering the antenna.
The radio provides a remote amplifier mute output circuit to control overall muting of the remote amplifier. The amplifier receives pulse width modulated (PWM) signals on the control circuit at varying duty cycle percentages for controlling muted and unmuted functions of the amplifier. Circuitry internal to the radio monitors the remote amplifier mute circuit for faults and sets the appropriate DTC when faults are detected.
The vehicle communication interface module (VCIM) is a 3-watt cellular device that allows the user to communicate data and voice signals over the national cellular network. It is powered by a fused, battery voltage circuit connected through the vehicle wiring to the 3-button OnStar® assembly located on the inside rearview mirror. The VCIM and radio are attached by means of coax cables to the cellular and navigation antennas. The module houses 2 modems, one to process global positioning system (GPS) data, and the other for cellular information. Satellites orbiting earth are constantly transmitting signals of their current location, from which the OnStar® system is able to pinpoint its own location. The navigation antenna receives these GPS signals and provides the data to the VCIM to be processed. The VCIM communicates with the rest of the vehicle over the GMLAN serial data bus. The module also has the capability of commanding the horn, initiating door lock/unlock and operating the exterior lamps using the serial data circuits.
When an OnStar® keypress is made, a GMLAN serial data message is sent to the audio system to mute all radio functions and transmit OnStar® originated audio. After the audio system is muted, the OnStar® signals are transmitted to the audio system on the cellular telephone voice signal circuit, and returned to the module on the cellular telephone voice low reference circuit. The cellular modem connects the OnStar® system to the cellular carriers 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.
The cellular antenna is connected to the vehicle communication interface module (VCIM) with a RG-58 shielded coaxial cable. The antenna cable also provides a path for DC current for powering the cellular antenna.
The OnStar® button assembly located on the inside rearview mirror consists of 3 buttons, Call/Answer, OnStar® Call Center, and OnStar® Emergency. The communication interface module (CIM) supplies the OnStar® button assembly via the 10-volt reference circuit. Each of the buttons, when pressed, completes the circuit across a resister allowing a specific voltage to be returned to the CIM over the keypad signal circuit. Depending upon the voltage range returned, the CIM is able to identify which button has been activated.
The OnStar® button assembly located on the inside rearview mirror consists of 3 buttons, Call/Answer, OnStar® Call Center, and OnStar® Emergency. The communication interface module (CIM) supplies the OnStar® button assembly via the 10-volt reference circuit. Each of the buttons, when pressed, completes the circuit across a resister allowing a specific voltage to be returned to the CIM over the keypad signal circuit. Depending upon the voltage range returned, the CIM is able to identify which button has been activated.
The navigation radio receives information from a specific navigation antenna located on the outside of the vehicle. The navigation antenna is connected to the vehicle communication interface module (VCIM) via a shielded coaxial cable. The antenna cable also provides a path for DC current for powering the antenna.
The digital radio receiver (DRR) receives XM satellite radio signals via a digital radio antenna located on the outside of the vehicle. The signal is passed to the DRR through digital radio antenna coax. From the DRR, separate left and right audio signals (+) are sent to the radio. The radio processes these signals and passes the audio to the appropriate speakers or audio amplifier.
The vehicle communication integration module (VCIM) contains two modems, one to process global positioning system (GPS) data, and the other for cellular information. Satellites orbiting earth are constantly transmitting signals of their current location, from which the OnStar® system is able to pinpoint its own location. The navigation antenna housed in the quad band radio antenna receives these GPS signals and provides the data to the VCIM to be processed. The navigation antenna is connected to the vehicle communication interface module (VCIM) via a shielded coaxial cable. The antenna cable also provides a path for DC current for powering the antenna.
The communication interface module (CIM) provides the cellular microphone with a supplied voltage on the cellular microphone signal circuit. When the microphone is in use, voice data from the user is sent back to the CIM by means of the signal circuit.
When an OnStar® keypress is made, a serial data message is sent to the audio system to mute all radio functions and transmit OnStar® originated audio. After the audio system is muted, the OnStar® signals are transmitted to the audio system on the cellular telephone voice signal circuit, and returned to the module on the cellular telephone voice low reference circuit. The cellular modem connects the OnStar® system to the cellular carriers communication system by interacting with the national cellular infrastructure. The module sends and receives all cellular communications over the cellular/navigation antenna and cellular antenna coax.
The vehicle communication interface module (VCIM) is a 3-watt cellular device that allows the user to communicate data and voice signals over the national cellular network. It is powered by a fused battery positive voltage circuit, connected through the vehicle wiring to the inside rearview mirror containing the 3-button assembly and the radio. The VCIM receives its cellular signals by means of coax cables to the cellular and navigation antennas. Ground for the module is accomplished by means of dedicated circuits that are routed with body wiring systems to chassis ground points. The module houses 2 modems, one to process global positioning system (GPS) data, and the other for cellular information. Satellites orbiting earth are constantly transmitting signals of their current location, from which the OnStar® system is able to pinpoint its own location. The navigation antenna receives these GPS signals and provides the data to the VCIM to be processed. The VCIM communicates with the rest of the vehicle over the class 2 or GMLAN serial data bus, depending upon the serial data architecture of the vehicle. The ignition state is determined by the VCIM through class 2 or GMLAN messaging. The module also has the capability of commanding the horn, initiating door lock/unlock, and operating the exterior lamps using the serial data circuits. When an OnStar® keypress is made, a serial data message is sent to the audio system to mute all radio functions and transmit OnStar® originated audio. After the audio system is muted, the OnStar® signals are transmitted to the audio system on the left audio signal circuit (+) and the audio common signal circuit. The cellular modem connects the OnStar® system to the cellular carriers 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.
The OnStar® button assembly located on the inside rearview mirror consists of 3 buttons, Call/Answer, OnStar® Call Center, and OnStar® Emergency. The communication interface module (CIM) supplies the OnStar® button assembly with 10 volts via the keypad supply voltage circuit. Each of the buttons, when pressed, completes the circuit across a resister allowing a specific voltage to be returned to the CIM over the keypad signal circuit. Depending upon the voltage range returned, the CIM is able to identify which button has been activated.
The vehicle communication interface module (VCIM) is a 3-watt cellular device that allows the user to communicate data and voice signals over the national cellular network. It is powered by a fused, battery positive, voltage circuit connected through the vehicle wiring to the 3-button assembly and the radio, and attached by means of coax cables to the cellular and navigation antennas. Ground for the module is accomplished by means of dedicated circuits that are routed with body wiring systems to chassis ground points. The module houses 2 modems, one to process global positioning system (GPS) data, and the other for cellular information. Satellites orbiting earth are constantly transmitting signals of their current location, from which the OnStar® system is able to pinpoint its own location. The navigation antenna receives these GPS signals and provides the data to the VCIM to be processed. The VCIM communicates with the rest of the vehicle over the serial data bus. The ignition state is determined by the VCIM through serial data messaging. The module also has the capability of commanding the horn, initiating door lock/unlock and operating the exterior lamps using the serial data circuits. When an OnStar® keypress is made, a serial data message is sent to the audio system to mute all radio functions and transmit OnStar® originated audio. After the audio system is muted, the OnStar® signals are transmitted to the audio system on the cellular telephone voice signal circuit, and returned to the module on the cellular telephone voice low reference circuit. The cellular modem connects the OnStar® system to the cellular carriers 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.
AM and FM radio reception is dependent on the following components
- Radio antenna - part of the rear window
- Coax cable between the radio antenna and the radio antenna module
- Radio antenna module
- Coax cable between the radio antenna module and the radio
- Radio
Each of the audio output channel circuits (+) and (-), at the radio and audio amplifier have a DC bias voltage that is one half of the battery voltage. When using a DMM, each of the audio output channel circuits will measure approximately 6.5V DC. The audio being played on the system is produced by a varying AC voltage that is centered around the DC bias voltage on the same circuit. The AC voltage is what causes the speaker cone to move and produce sound. This voltage will vary depending on what type of audio is being listened to, talk or music, and type of music, as well as the volume setting of the system. Low volume and talk settings will measure around 1V AC and less, where constant music may measure 3V AC and slightly higher. In an amplified audio system, these similar AC voltage measurements may be slightly higher on the output of the amplifier, and the typical AC voltage readings at the output of the radio are less than 1V AC.
The communication interface module (CIM) is a 3-watt cellular device that allows the user to communicate data and voice signals over the national cellular network. It is powered by a fused, battery voltage circuit connected through the vehicle wiring to the 3-button assembly and the radio, and attached by means of coax cables to the cellular and navigation antennas. Ground for the module is accomplished by means of dedicated circuits that are routed with body wiring systems to chassis ground points. The module houses 2 modems, one to process global positioning system (GPS) data, and the other for cellular information. Satellites orbiting earth are constantly transmitting signals of their current location, from which the OnStar® system is able to pinpoint its own location. The navigation antenna receives these GPS signals and provides the data to the CIM to be processed. The CIM communicates with the rest of the vehicle over the class 2 or GMLAN serial data bus, depending upon the serial data architecture of the vehicle. The ignition state is determined by the CIM through class 2 or GMLAN messaging. The module also has the capability of commanding the horn, initiating door lock/unlock and operating the exterior lamps using the serial data circuits. When an OnStar® keypress is made, a serial data message is sent to the audio system to mute all radio functions and transmit OnStar® originated audio. After the audio system is muted, the OnStar® signals are transmitted to the audio system on the cellular telephone voice signal circuit, and returned to the module on the cellular telephone voice low reference circuit. The cellular modem connects the OnStar® system to the cellular carriers 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.
OnStar Description and Operation
This vehicle uses the Generation 6.1 version of the OnStar® system. This system consists of the following components
- Vehicle communication interface module (VCIM)
- OnStar® button assembly
- Microphone
- Cellular antenna
- Navigation antenna
This system also interfaces with the factory installed vehicle audio system.
Operation of the Hands Free Cellular Phone
Onstar® personal calling (OPC) operates similar to most hand held cellular phones in that the availability for its usage is based on minutes or units. The customer must have a current OnStar® subscription, as this feature cannot be utilized without it. To use OPC, the customer must also purchase units as outlined in the owner's guide provided with the OnStar® system. When the customer purchases minutes, an OnStar® advisor loads these minutes into the vehicle communication interface module (VCIM) over the airwaves at the time of the request, or through a discrete cellular call to the vehicle at a later time. Once loaded into the module, the units may be used for non-international, outbound cellular phone calls, and connection with the OnStar® virtual advisor. Units begin to deplete, 1 unit is equal to 1 minute, as the customer makes outbound phone calls, answers inbound phone calls, or while connected to the OnStar® virtual advisor. In addition, units also have an expiration date, depending upon the type of units purchased. This date is established when the download is performed, and any remaining units expire when the date within the VCIM, which is based on current date and the time transmitted by global positioning system (GPS) satellites, has passed. At any time, the user can press the answer/end call button, say "Units" and verify the number of units remaining.
During a hands free call, the microphone and audio system operate the same way as a standard OnStar® call. When the answer/end call button is pressed, the audio system will mute; the OnStar® system will then return the prompt "OnStar Ready." At this point there are specific commands set to initiate a cellular call. If the vehicle receives a call when the radio is ON, the audio system will mute and an audible ring will be heard though the speakers. The call will be answered when the answer/end call button is pressed.
The VCIM interprets all of the voice-activated commands. A complete list of these commands is supplied in the information provided to the customer. If the information is not available to reference, at any command prompt the caller can say "HELP" and the VCIM will return an audible list of available commands. If the customer concern is not being understood or not being heard by the OnStar® system, the user should place a call to the OnStar® call center to verify proper operation of the microphone. Following this description is an example of the commands and the OnStar® system responses. A complete list of commands is supplied in the information provided to the customer with the OnStar® system.
Mobile Identification Number and Mobile Directory Number
The Generation 6.1 vehicle communication interface module (VCIM) utilizes 2 numbers for cellular device identification, call routing and connection, a mobile identification number (MIN) and a mobile directory number (MDN). The MIN represents the number used by the cellular carrier for call routing purposes while the MDN represents the number dialed to reach the cellular devise. Although technicians have the capability to change these numbers by means of the scan tool, this should ONLY be done at the direction of and with explicit instruction from General Motors Technical Assistance Center (GM TAC).
Operation of the OnStar® Speech Recognition Systems
OnStar® Generation 6.1 users communicate with 2 speech recognition systems. Speech recognition allows the user to speak to one computer in the vehicle, and one reached over a phone line. The computer tries to understand the users command, and responds by speaking back, or by taking the appropriate action, e.g. dialing the phone.
- Personal Calling uses a speech recognition system that resides in the vehicle. When the user presses the dot button, the system states, Ready, and listens for the user's command. The user can speak commands to control the hands-free phone.
- Virtual advisor is a remote speech recognition system that the caller access by making a phone call. The user connects to virtual advisor by requesting it during personal calling use. The user is then transferred to the virtual advisor server and talks to it via a cellular connection.
The OnStar® speech recognition systems use speech technology that is designed to understand a wide range of American English speakers. Although there is no one right way to speak English, the system will work best when users try to modify their pronunciation should they encounter difficulty. Users who do not obtain good results are advised to try the tips and workarounds found in this section.
| Concern | Tip for Better Result |
|---|---|
| Noise | Noise may confuse the speech recognition system. You usually get better performance from the system in quieter conditions: The HVAC fan creates noise. Turn it down or OFF for better speech system performance. Driving at high speeds creates louder engine noise and wind noise. You may get better results at lower speeds. An open window or an open sunroof allows more noise to enter the vehicle. Close all windows for better results. Noisy rainstorms can also reduce performance. If passengers are talking while you use the speech system, it may be confused by their speech. You will get better results if all occupants of the vehicle are quiet while the system is listening for commands. |
| When to Speak | In Personal Calling, the system is only listening after it prompts you to speak. When the system prompts you to speak, you have about 5 seconds to respond. If the system does not hear a response, it will prompt you again, or cancel the transaction. If you begin to speak too soon, it will tell you "Slower, please." Try pausing for a half second before speaking. In the Virtual Advisor, the system is always listening for commands, even while it is speaking. |
| How to Speak | Speak forcefully, and clearly. The noisier the environment, the louder you need to speak. If you are in the driver seat, speak facing the front of the car. If you are a passenger, speak facing the rearview mirror. Speak calmly, and naturally. The system may sometimes fail your repeated attempts to give a command. If your speech is distorted by shouting or frustration, this may cause more errors. People with high-pitched voices may have better results by speaking in a deeper, lower-pitched voice. However, do not lower the volume of the voice. Avoid speaking with a rising intonation, like asking a question. Use a flat or falling intonation, like giving an answer. |
| What to Say | Personal Calling: One-word commands The Personal Calling system listens for only one word at a time. There are some exceptions, 2-word phrases that are spoken and understood as a single word, e.g. 'virtual advisor', 'voice feedback', and 'my number'. You can enter phone numbers only one digit at a time, and the system repeats each digit as it hears it. Say "Help" at the Ready prompt to hear the list of Personal Calling commands. Virtual Advisor can understand sentences with more than one word. It also expects to hear a 4-digit number all at once when it asks for your PIN. Say, "What are my choices?" to hear a list of commands that the Virtual Advisor understands. |
| Entering a phone number | If you have trouble getting numbers correctly into the system, store your frequently-called number in the directory, so the system will remember them. After you have stored a number with a nametag, then you simply say 'call' and the nametag in order to call the number. If the system cannot understand your numbers, ask another person to help you enter your frequently-called numbers. This person can speak the numbers, then you can speak the nametag. |
| Storing or dialing a number | When you have finished speaking your phone number, you do not need to say 'store' or 'dial' to indicate that you are done. If you pause and say nothing, the system will ask you if you want to store or dial. Say 'yes'. |
| Creating nametags | Short nametags that are similar may be easily confused by the system. You may get better recognition of your nametags if you make them longer, for example 'George Washington' without pause, instead of 'George' only. If you want to use nametags while driving, it is best to store the nametag with some vehicle noise in the background. If you are in park while you are storing nametags, you can turn the fan on low or open windows in order to create some background noise. |
| Virtual Advisor 4-digit PIN | Say the 4 digits in a natural way, without pausing between digits. |
| Interrupting | When the Virtual Advisor is speaking, you can interrupt it with another command. The first word in your command helps to get its attention. If the Virtual Advisor has trouble understanding your commands when you interrupt, try speaking the first word loudly and clearly, then pause for an instant, then continue with the rest of the command. For example: "Get .. my weather" or "Lookup... a quote for General Motors". |
General Tips for Better Speech Recognition
| Command | Tip for Better Result |
|---|---|
| 'add' | Emphasize the 'd' at the end of the word. |
| 'call' | Emphasize the 'l' at the end of the word. |
| 'cancel' | Emphasize the 'l' at the end of the word. If you are speaking the 'can' syllable very quickly, try to lengthen it a little. |
| 'clear' | Emphasize the 'r' at the end of the word. |
| 'delete' | Emphasize the 't' at the end of the word. Do not swallow the 'd' at the start of the word. |
| 'dial' | Emphasize the 'l' at the end of the word. |
| 'digit dial' (Gen 6) | Combine the words smoothly and emphasize each syllable. |
| 'directory' | Speak all 4 syllables clearly. Do not swallow the last part of the word. |
| 'help' | Emphasize the 'h' sound at the start of the word. Emphasize the 'p' sound at the end of the word. |
| 'my number' | Emphasize all 3 syllables. |
| 'no' | Speak loudly and slowly. Emphasize the 'n' sound at the start of the word. Draw out the 'o' sound at the end of the word. |
| 'redial' | Try to emphasize and lengthen the first syllable: reee-dial |
| 'security' | Speak 4 syllables clearly. Do not swallow the 'i' sound in the middle of the word. |
| 'store' | Emphasize the 'o' sound in the middle of the word in order to distinguish from 'star'. Emphasize the 'st' sound at the start of the word in order to distinguish from 'four'. |
| 'units' | Speak loudly and clearly. |
| 'verify' | Speak 3 syllables clearly. Do not swallow the 'i' sound in the middle of the word. |
| 'Virtual Advisor' | Emphasize both words. |
| 'voice feedback' | Emphasize both words. |
| 'yes' | Emphasize the 'y' sound at the start of the word. Emphasize the 's' sound at the end of the word. |
| 'zero', 'oh' | If the system does not understand 'oh', try 'zero', or vice versa. |
| 'one' | Emphasize the 'n' at the end of the word. |
| 'two' | Round your lips for the 'ooo' part of the word. If you are clipping the 'ooo' very short, try to lengthen it, but do not draw it out excessively. Speak in a low pitch. Do not use a rising tone like asking a question; a falling tone like giving an answer is better. |
| 'three' | End the word 'three' in a smile, to draw back your lips. Lengthen the 'eee' sound if you are clipping it very short. |
| 'four' | Emphasize the 'r' at the end of the word. |
| 'five' | Emphasize the 'v' sound. |
| 'six' | Emphasize the 'ks' sound at the end of the word. |
| 'seven' | Emphasize the 'n' at the end of the word. Lengthen the 'sev' syllable. |
| 'eight' | Emphasize the 't' at the end of the word. Lengthen the 'eee' sound at the start of the word. |
| 'nine' | Emphasize the 'n' sounds to distinguish from 'five'. |
| 'star' | Emphasize the 'r' at the end of the word. Emphasize the 'ah' sound in order to distinguish from 'store'. |
| 'pound' | Emphasize the 'p' at the start of the word. Emphasize the 'd' at the end of the word. |
Personal Calling Commands
Radio/Audio System Description and Operation
The entertainment system on this vehicle is configured with either a base or an uplevel system. Both the base and uplevel systems contain a radio, antenna, speakers, and on some vehicle lines a rear seat audio (RSA) unit.
The uplevel system differs from the base level system by providing enhanced audio system features. These features may include the radio data system (RDS), two additional speakers, rear seat audio (RSA), and DVD video entertainment system. The uplevel radio units are also OnStar and XM Radio compatible.
The radio head includes the driver information display (DID). Driver information is provided to the radio head via GMLAN serial data link to the body control module (BCM).
The following list shows the radios available for this vehicle
- Base Radio (U1C)-AM/FM Stereo with CD
- Uplevel Radio (UN0)-AM/FM Stereo, CD, Auto Tone, and RDS
- Uplevel Radio (UP0)-AM/FM Stereo, Cassette, CD, and RDS
- Uplevel Radio (UC6)-AM/FM, Integral 6 Disc CD Changer (ICDX), and RDS