GM Service Manual Online
For 1990-2009 cars only
Table 1: Radio Features
Table 2: Cassette Features
Table 3: Compact Disc Features
Table 4: XM Advisory Messages

The Entertainment System on this vehicle is configured with a radio, antenna, and speakers.

The following list shows the radios available for this vehicle:

    â€¢ Radio (UB0) - AM/FM with CD
    â€¢ Radio (UB1) - AM/FM, Cassette and CD
    â€¢ Radio (UC6) - AM/FM, Integral Multi Disc CD Changer
    â€¢ Navigation Radio (UM8) - RADIO - AM/FM Stereo, Seek/Scan, CD, ETR, Navigation, Clock

Radio Features

Controls

Functions

All Radios, except UM8

Power

Push PWR/PUSH/VOL knob to turn the radio ON.

Volume

The volume is adjusted by rotating the PWR/PUSH/VOL knob.

Automatic Volume Control

Press the AUTOVOL button.

Tune

Turn the TUNE/SELECT/PUSH RCL knob.

Seek

Momentarily press the SEEK/SCAN button.

Scan

Hold the SEEK/SCAN button at least 4 seconds.

Presets

Six AM, Six FM1 and Six FM2

Preset Saving

Press and hold desired button until an audible beep is heard.

Set Clock

Press and hold the HR or MN button until an audible beep indicates the time set mode has been entered. Once the beep is heard, the time can be set by tapping each button to incrementally adjust the time. Holding down each button will rapidly change the time.

Recall

Push the TUNE/SELECT/PUSH RCL knob.

Fade or Balance

Press the BAL/FADE button to select and adjust w/SELECT knob.

Bass, Treble or Midrange

Press the TONE button to select and adjust w/SELECT knob.

Automatic Tone

Press AUTO TONE button.

Navigation Display Head, UM8

Power

Push PWR/VOL knob to turn the radio on.

NAV

Displays the map guidance screen.

NAV RPT

Repeats the last voice guidance message.

SETUP

Displays the setup function for the Navigation Radio.

Scroll/Select knob

Push to display menu/Move up/down and left/right to highlight selection/Push to select.

Soft Key Buttons

Push to select the options listed on the navigation screen.

Cassette Features

Controls

UB1 Radio

Eject

EJECT button

Fast Forward

Preset button 1

Reverse

Preset button 4

Auto Reverse

Yes

Side

Preset button 5

Previous

Preset button 1

Next

Preset button 2

Dolby

Preset button 6

Repeat

NA

Compact Disc Features

Controls

UB1 Radio

UB0 Radio

UC6 Radio

Eject

EJECT button

Fast Forward

Preset button 1

Reverse

Preset button 4

Disc

Preset button 5

Previous

Preset button 1

Next

Preset button 2

Dolby

Preset button 6

Repeat

NA

Random

Preset button 6

Each item in the list below represents topics covered in detail below.

    â€¢ AM/FM Reception
    â€¢ Theft Deterrent
    â€¢ Integral Multi Disc CD Changer (IMDX)
    â€¢ Amplifier
    â€¢ Automatic Volume Control
    â€¢ Radio Data System (RDS)
    â€¢ Tape/CD Player Error Messages
    â€¢ Rear Seat Audio (RSA)
    â€¢ XM Satellite Radio

AM/FM Reception

Radio Signal

The radio signal is sent from a broadcast station and is then received by an antenna. The strength of the signal received depends on the following:

    â€¢ The power output (wattage) of the broadcasting station
    â€¢ The location of the vehicle (or receiver) relative to the broadcast tower.
    â€¢ Obstacles between the tower and the receiver
    â€¢ Atmospheric conditions
    â€¢ What band (AM or FM) the station is broadcasting
    â€¢ Type of antenna and the ground plane

AM Reception

The AM band has a lower frequency range than the FM band. These longer wavelengths:

    â€¢ Bend around Obstacles
    â€¢ Follow the curvature of the earth
    â€¢ May reflect off the ionosphere (skip)

The AM frequencies have longer range due to the ground wave. The ground wave follows the curvature of the earth and is effected by its conductivity. Greater conductivity equates to less signal loss thus transmission over water is better than over land. The AM band has a range of 80-320 km (50-200 mi).

FM Reception

The shorter wavelengths of the higher frequency FM band:

    â€¢ Reflect off obstacles
    â€¢ Are absorbed by the ground
    â€¢ Penetrate the ionosphere

Broadcasts in the FM band are limited to "line of sight" reception which is typically 40 km (25 mi). Even when out of a direct line of sight, the signal may be reflected into areas that would be in a "shadow" otherwise. Factors which affect the line of sight include:

    â€¢ Height of the broadcast antenna
    â€¢ Height of the receiving antenna
    â€¢ Terrain and buildings in the broadcast path

XM Satellite Radio

XM satellite radio provides digital radio reception. The XM signal is broadcast from two satellites and, where necessary, terrestrial repeaters. The high power satellites allow the antenna to receive the XM signal even when foliage and other partial obstructions block the antennas view of the satellite. Terrestrial repeaters are used in dense urban ares. These repeaters will receive the satellite signal and re-broadcast them at much higher power levels in order to ensure reception in areas with densely packed tall buildings.

Theft Deterrent

The theft deterrent system is a feature on all base and uplevel radios. There is no need to program a security code into the radio as in past model years. The theft deterrent system now utilizes class 2 serial data to determine if the radio is in the appropriate vehicle. Each time the radio receives the "run" power mode message, it compares the VIN information it has stored to the VIN information received from a module on the class 2 serial data circuit responsible for transmitting that information. If a mis-match occurs, the radio display will indicate to the user the radio is locked. Once this takes place the radio will not respond to any button presses and become inoperative. The two scenarios able to cause this condition are:

    â€¢ A radio is installed from another vehicle.
    â€¢ A module which communicates on the class 2 serial data circuit which supplies VIN information to the radio is replaced and not properly setup with the correct VIN information for that vehicle.

The only way to unlock the radio is by using a scan tool.

The digital radio receiver utilizes class 2 serial data to determine if it is in the appropriate vehicle. Each time the digital radio receiver receives the "run" power mode message, it compares the VIN information received from the body control module (BCM) on the class 2 serial data circuit. If a mis-match occurs, the radio display will indicate to the user the digital radio receiver is locked. The digital radio receiver cannot be unlocked, it must be replaced. The two scenarios able to cause this condition are:

    â€¢ A digital radio receiver is installed from another vehicle.
    â€¢ The BCM is replaced and not properly setup with the correct VIN information for that vehicle.

Integral Multi Disc CD Changer (IMDX)

The integral multi disc CD changer has the capability of storing and playing up to six (6) compact discs. The integral multi disc CD changer has a shock-absorbing system. Only under extreme operating temperatures or severe shock or vibration should the compact disc player skip or mute. If the customer travels an abnormally rough road, a skip condition may be normal. Test drive the vehicle on a normal road with a known good CD. If the condition is still present, replace the radio.

The use of CD lens cleaner discs is not advised, due to the risk of contaminating the lens of the CD optics with lubricants internal to the CD mechanism.

Single Disc Loading

To operate the integral multi disc CD changer in the single play mode, press the "LOAD" button for less than two seconds. The LED to the right of the disc door will turn green to indicate the CD can be loaded. Insert the disc into the slot, label side up. The player will pull the disc in.

Multi Disc Loading

To operate the changer in the multi disc mode, press the "LOAD" button for more than two seconds and the LED to the right of the disc door will flash. Once the light stops flashing and turns green you can load a disc. Insert the disc into the slot, label side up. The player will pull the disc in. Once the disc is loaded, the light will begin flashing again. Once the light stops flashing and turns green you can load another disc.

Removing CDs

Use the eject button to remove a disc or discs. Perform the following to eject:

    â€¢ To remove a single disc, press and release the eject button. The message "REMOVE CD" is displayed.
    â€¢  To remove multiple discs, press and hold the eject button for two seconds. An audible beep is heard and the LED to the right of the disc door begins to flash indicating a disc is being ejected. The message "REMOVE CD" is displayed.

Amplifier

The amplifier does not communicate over the serial data circuits and therefore the amplifier will not set DTCs.

Automatic Volume Control

With automatic volume, the audio system adjusts automatically to make up for road and wind noise by increasing the volume as vehicle speed increases. The Bose amplifiers and base radios use a vehicle speed signal, received via serial data circuits to adjust volume. To adjust volume based on speed, press the AUTO VOL button to select LOW, MEDIUM, or HIGH. To turn AUTO VOL off, press until AVOL OFF is displayed.

Radio Data System (RDS)

All uplevel audio systems are equipped with technology known as the radio data system (RDS). RDS is a system that sends data along with the audio of the FM station you are currently tuned to. RDS is a standard that defines how a FM broadcast station may send digital data along with the audio program. Think of it as a one way wireless modem, allowing the broadcaster to send information about his program to your receiver.

RDS data is carried in what is known as a "sub-carrier". A sub-carrier is a frequency that the FM broadcaster is authorized to use to send data or other audio programs that are not audible in the main audio program. RDS information can be used to display program information and to control the radio.

To receive the RDS signal, all that is needed is an FM receiver with a RDS circuit. A special integrated circuit capable of dealing with the RDS signal is in the RDS circuit and passes it along to the receiver's microprocessor where it is decoded and acted upon.

RDS Basic Information

RDS basic information:

    â€¢ RDS functions are provided in the FM broadcast band only.
    â€¢ RDS functions will only work with FM broadcast stations that are broadcasting RDS data.
    â€¢ Not all FM Broadcast stations broadcast RDS data or offer all of the RDS services.
    â€¢ RDS functions may not work properly when reception is weak, reception is of poor quality, or RDS is not implemented properly by the FM Broadcaster.

In some cases, a radio station broadcasting incorrect information may cause the RDS features of the radio to appear to work improperly.

Broadcast RDS information can be used in a variety of ways by the receiver and listener, but basically falls into two categories: Display and Control.

Displaying Program Information

RDS displays textual information such as:

    â€¢ The name of the station.
    â€¢ The type of program.
    â€¢ General information such as artist and song title, call in phone numbers, etc.

RDS is always on. When tuned to a non-RDS station, your radio will display frequency information as you would normally expect. When tuned to a RDS station, your radio will change from displaying the frequency of the FM station to displaying the call letters of the station or display the nickname of the station. This feature is known as the Program Service Name.

Controlling the Radio

RDS can control the radio when data the receiver can use responds to timely information performing the following:

    â€¢ Interrupt the playback of your cassette or CD for traffic or emergency bulletins.
    â€¢ Search for stations by type of program.
    â€¢ Automatically follow networked programming from transmitter to transmitter as you travel from one listening area to another.
    â€¢ Set your clock to the time that the RDS Broadcast station broadcasts.

Viewing and Selecting RDS Information for Display

Press the TUNE knob once for less then 2 seconds when the radio displays the program service name and the frequency of the station will be displayed. Press the knob again, and the program type (PTY) will be displayed. Pressed again, and the program name will be displayed (if the broadcaster is broadcasting one). The program name is an eight-character name that the broadcaster may use to further identify the type of programming currently being broadcast.

Using the RDS Traffic Feature

Some RDS broadcasters may carry traffic information programming to inform you of current traffic conditions in your listening area and is indicated by the icon in the radio display. RDS enables the broadcaster to get this information to you even when you are listening to a tape or compact disc. This feature can be enabled or disabled by the listener. Press the "TRAF" button to find a station that claims to carry traffic information. You may do this even when playing a cassette tape or compact disc. This action will operate in the background without interrupting the current playback. If the radio is not currently tuned to an RDS traffic station, the radio will immediately SEEK an RDS traffic station. If the radio finds an RDS traffic station, the" TRAF" icon will appear in the radio display as will brackets around the (TRAF) icon. If the radio cannot find an RDS traffic station after searching through the entire FM band, the radio will display "NO TRAFFIC".

Alternate Frequency (AF) Switching

RDS permits broadcaster's to send information to the radio that allows the radio to automatically switch frequency to the best quality station in that broadcaster's network.

Since the radio is displaying the broadcaster call letters or nickname, the listener will not see the frequency during an AF switch unless you have changed the default display to be frequency instead of Program Service name.

To enable or disable AF switching perform the following:

    â€¢ Press and hold the AM/FM button for two seconds or more.
    â€¢ The radio will display AF ON or AF OFF depending on the current condition of AF and a confirmation beep will be heard.

When AF is enabled and you recall a RDS station stored on preset, the radio determines if the station stored is of acceptable quality. If not, the radio checks all available AF's for your station. If the radio fails to locate your program, AF SEARCH will be displayed as the radio scans across the band looking for your program or an affiliated network. If the radio cannot find the original station or an acceptable alternate frequency NOT FOUND will be displayed and the radio returns to the original frequency for the preset.

RDS Clock Time

Broadcasters can choose to send clock time information in the RDS data. This information can be used to update the clock time on the radio. RDS clock time is broadcasted once a minute. To set the clock using RDS clock data perform the following:

    â€¢ Press and hold the HR and MIN buttons together for two or more seconds to update the time.
    â€¢ The display will show UPDATED after receiving the broadcasted time data.
    â€¢ If the broadcaster is not broadcasting the time data, the radio will display NO UPDATE and the time remains unchanged.

Radio Error Messages

The radio displays the following error messages:

CHECK CD: Displays when the player encounters a focus or tracking error.

CHK CDXX: Displays when the CD changer encounters a focus or tracking error, If equipped.

CHK TAPE: Displays if a tape has been inserted but is unable to be played due to an error.

NO DISC: Displays when the radio expected a disc to be inserted.

NONE: Displays when the radio is unable to detect the vehicle speed data information via the class 2 serial data circuit.

Voice Recorder

To record a message, press the button with the circle on it and begin speaking. Press the button with the circle on it again to stop recording. System allows you to record up to 4 minutes of messaging.

You may also press and hold the button with the circle on it while you are speaking and then let it go when you are finished.

To play back messages, press the button with the right arrow on it. Pressing the right arrow button more than once will return you to previously recorded messages. If you press and hold this button for more than 1 second, all of the recorded messages will be played back.

To delete messages, press the button with the square on it while the message is playing. If you press and hold the right arrow button and the circle button at the same time for a half of a second, all of the messages will be deleted.

Rear Seat Audio (RSA)

The rear seat audio (RSA) and rear HVAC control functions are combined into one dual function control unit. The rear seat audio (RSA) control allows the rear seat passengers to listen to a different music source than the front seat passengers. The rear seat passengers can only control the music sources that the front seat passengers are not listening to. For example, the rear seat passengers may listen to the cassette or CD through headphones while the driver listens to the radio through the front speakers. The rear seat passengers have control of the volume for each headphone. The primary radio controls always override the RSA controls.

Power (PWR)

Press the PWR button in order to turn the rear seat audio system ON or OFF. The rear speakers mute when the power is turned ON unless you have a Bose equipped vehicle. The rear seat audio functions are operable even when the primary radio power is OFF.

Volume (VOL)

Rotate the volume knob in order to increase or decrease the volume. The left volume knob controls the left headphone and the right volume knob controls the right headphone.

Source Switching

Press the PROG or SRCE button in order to switch between playing a cassette or a CD and listening to the radio. There must be a cassette tape and/or compact disc in the player.

Seek (SEEK)

Press the SEEK button in order to seek to the next station. The display will show your selection.

Preset Scan

Press and hold the SEEK button in order to scan station presets.

Next

While listening to a CD or cassette, press the SEEK button in order to hear the next track.

XM Satellite Radio

XM is a national satellite radio service that offers up to 100 coast to coast channels including music, news, sports, talk and children's programming. XM provides digital quality audio and text information, including song title and artist name. A service fee is required in order to receive the XM service. For more information, contact XM at www.xmradio.com or call 1-800-852-9696.

Digital Radio Receiver

The radio controls communicate with the digital radio receiver via the class 2 communication circuit. The digital radio receiver sends low level audio signals to the radio.

Viewing Messages

Press the TUNE/SELECT/RCL knob while in XM mode to view various pieces of information related to the current song or channel. By pressing TUNE/SELECT/RCL knob, you may view four different categories of information: Artist Name/Feature, Song/Program Title, Channel Category, and other Additional Information that may be broadcast on that channel. Additional Information messages may not always be available. Each of the four information types may have multiple pages of text. To reach a category, press TUNE/SELECT/RCL knob consecutively until the desired type is displayed. If there are multiple pages of text for the selected information type, the radio will automatically display all the pages for that type at a rate of approximately one page every three seconds before timing out and returning to the default display. You may override this feature by pressing the TUNE/SELECT/RCL knob to review all of the pages at your own pace.

Selecting a Program Type

The TUNE/SELECT/RCL knob can be used to scroll through the list of available program types (PROG TYPE). Press the PROG TYPE button, then turn the TUNE/SELECT/RCL knob to scroll through the available program types. When the desired program type is shown on the display, press the SCAN button. The radio will seek the next station of that type.

XM Advisory Messages

Radio Display Message

Condition

XM Updating

Updating encryption code

No XM Signal

Loss of signal

Loading XM

Acquiring channel audio (after 4 second delay)

Channel Off Air

Channel not in service

Channel Unavail

Channel no longer available

No Artist Info

Artist Name/Feature not available

No Title Info

Song/Program Title not available

No CAT Info

Category name not available

Not Found

No channel available for the chosen category

No Information

No text/informational message available

XM Theftlocked

Theft Lock active

XM Radio ID

Electronic serial number (ESN) channel 0

Unknown

Radio ID not known (should only be if hardware failure

Check XM Receiver

Hardware failure