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

The entertainment system on this vehicle is configured with an uplevel system. The uplevel system contains a radio, antenna, speakers, and an audio amplifier. The uplevel system provides the customer with enhanced audio system features. Some of those features include the radio data system (RDS), extended range speakers, digital signal processing, weather capabilities and voice recognition. Satellite digital radio (U2K) is also available with RPO U2R.

The following list shows the radios available for this vehicle:

    • Uplevel Radio (U2R) - Navigation, AM/FM, Weatherband (WX), 6 Disc CD changer, DVD, RDS, DSP and Bose Amplifier (Domestic)
    • Uplevel Radio (U2S) - Navigation, AM/FM/LW, 6 Disc CD changer, DVD, RDS, DSP and Bose Amplifier (Europe)
    • Uplevel Radio (U2U) - Navigation, AM/FM, Weatherband (WX), 6 Disc CD changer, DVD, RDS, DSP, VICS and Bose Amplifier (Japan)

Radio Features

Controls

All Radios

Power

Push the PWR/VOL knob to turn the radio on.

Volume

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

Auto Volume Control

Press the music button, then touch the ON or OFF button.

Tune

Press the TUNE/SEEK button.

Seek

Press and hold the TUNE/SEEK button.

Scan

Press the SCAN button for less than 2 seconds.

Presets

Six AM, Six FM1, Six FM2, and six weather. Six XM1 and six XM2 if equipped with U2K.

Preset Saving

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

Preset Scan

Press the SCAN button for more than 2 seconds.

Preset Auto Set

Touch the Auto Set button to set the six strongest stations.

Set Clock

Press and hold the HR or MN button until the time begins to change. The time can be set by tapping each button to incrementally adjust the time. Holding down each button will rapidly change the time.

Mute

Press the MUTE button on the steering wheel controls (w/o K59).

Fade or Balance

Touch the Sound button.

Bass, Treble, or Midrange

Touch the Sound button.

Digital Signal Processing

Press and release the DSP button to select a DSP.

PTY

This button is only used with satellite digital radio.

Compact Disc Features

Controls

All Radios

Play/Stop

Press the CD button.

Eject

Press and hold the TILT button until the face lifts. To close, press and release the TILT button.

Fast Forward

Touch and hold the right arrow button.

Reverse

Touch and hold the left arrow button.

Next

Press the up arrow on TUNE/SEEK button.

Previous

Press the down arrow on TUNE/SEEK button.

Track Scan

Touch the SCAN TRACKS button.

Random

Touch RANDOM button.

Repeat

Touch the REPEAT TRACK button.

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

    • Radio Reception
    • Diversity Antenna System
    • Audio Amplifier
    • Theftlock
    • Remote Playback Device
    • Radio Personalization w/Home and Away Feature
    • Radio Data System (RDS)
    • Steering Wheel Controls
    • XM Satellite Radio

Radio 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:

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

AM Reception

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

    • Bend around Obstacles
    • Follow the curvature of the earth
    • 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 miles).

FM Reception

The shorter wavelengths of the higher frequency FM band:

    • Reflect off obstacles
    • Are absorbed by the ground
    • Penetrate the ionosphere

Broadcasts in the FM band are limited to "line of sight" reception which is typically 40 km (25 miles). 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:

    • Height of the broadcast antenna
    • Height of the receiving antenna
    • 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.

Diversity Antenna System

A diversity antenna system is designed to deliver the best radio signal reception possible. Two antennas are used to form a diversity system. The primary antenna, on the right side of the decklid liner, receives both AM and FM signals. The second antenna, on the left side of the liner, receives only FM signals.

The diversity antenna system consists of two separate antennas, and two radio antenna modules. The antennas on this vehicle consist of 20 gage stranded wire. These wires are termed elements, and are routed on the decklid liner to capture signals. Any damage to the antenna elements requires replacing the decklid liner assembly to which the elements are attached. The two radio antenna modules are , on the left side and the right side.

The antenna reception signals are sorted out by the radio antenna module. When the radio is turned on it sends the antenna enable signal to the right radio antenna module, providing power to the ARS antenna module. When the AM or FM band is selected on the radio, the antenna module connects the antenna elements directly to the radio. In addition, when the FM band is selected the FM composite signal is sent to the antenna module. Superimposed on this FM composite signal is the strength of the signal being received by the radio tuner. The antenna module now performs two functions. It switches between the left and right antennas, monitoring the radio signal strength and combines both signals, phase aligning them, to create one strong signal.

Audio Amplifier

Important: While operating the power folding top, the amplifier will mute momentarily to adjust the equalization settings.

The radio, digital radio receiver, or the CD changer supplies low level audio signals to the audio amplifier in order to boost the signal sent to the speakers.

The radio uses the antenna input signal to create a stereo audio output signal, which is sent at the user-defined volume level to the audio amplifier. The audio amplifier amplifies the signal and sends it to the appropriate speakers. Tone, balance and fade information is sent by the radio to the audio amplifier via the class 2 communication circuit. Additional output processing is provided by the noise-canceling microphone. The microphone monitors interior ambient noise allowing the audio amplifier to modify the audio output. This maintains the sound at an enjoyable level.

Theftlock

Radio

The "Theftlock" theft deterrent system is a feature on all 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 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 radio is locked. Once this takes place, a DTC will set, the radio will not respond to any button presses and become inoperative. The two scenarios able to cause this condition are:

  1. A radio is installed from another vehicle
  2. The BCM 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. Always refer to the table in this section to diagnose the "Theftlock" DTC for further information.

Digital Radio Receiver

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 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. This will occur if a digital radio receiver is installed from another vehicle. The digital radio receiver cannot be unlocked, it must be replaced.

CD Changer

The radio controls and communicates with the CD changer via the class 2 communication circuit. The CD changer is the main audio router for the XLR. Outputs from the radio, digital radio receiver (DRR) and the vehicle communication interface module (VCIM) are routed through the CD changer to the audio amplifier.

The CD changer allows for multiple compact discs to be played continuously without having to manually change compact discs. To load CDs, insert the CDs one at a time into the slot below the radio, label side up. If a disc is loaded label side down, the disc will not play and an error will occur. Care should be used to align and insert the disc into one disc tray only. Repeat this procedure for loading all of the discs in the changer. To eject a single CD press and release the eject button. To eject multiple CDs, press and hold the eject button for at least 2 seconds. Whenever a CD is loaded in the changer, the CD symbol will appear on the radio display.

Radio Personalization w/ Home and Away Feature (If equipped)

This feature allows two different drivers to store and recall specific radio settings. The settings recalled by the radio are determined by which remote keyless entry (RKE) transmitter (1 or 2) is used to enter the vehicle. The number on the back of the RKE transmitter corresponds to driver 1 or driver 2. The radio settings automatically adjust to where they were last set by the identified driver. The settings can also be recalled by briefly pressing the MEMORY seat button 1 or button 2 located on the driver's door.

The radio can store home and away presets. Home and away presets allow you to use one set of preset radio settings in the area where you live, and another set when you go out of town. That way, you do not need to reprogram your presets every time you travel. With the radio off and the clock displayed, use FF and RW to select home or away presets. In order to select the away presets, press and hold FF for 5 counts until you hear a beep. The next time the radio comes on, the away presets are active. In order to select the home presets, press and hold RW for 5 counts until you hear a beep. The next time the radio comes on, the home presets are active.

When battery power is removed and later applied, you do not have to reset your home radio presets because the radio remembers the presets. However, you do have to reset the away radio presets.

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 "subcarrier". A subcarrier 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:

    • RDS functions are provided in the FM broadcast band only.
    • RDS functions will only work with FM broadcast stations that are broadcasting RDS data.
    • Not all FM Broadcast stations broadcast RDS data or offer all of the RDS services.
    • 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:

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

Finding an RDS Station

To find an RDS station press the RDS button. The radio will seek to the next RDS station.

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 TA 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 TA 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, TA will appear in the radio display. If the radio cannot find an RDS traffic station after searching through the entire FM band, the radio will display "NO TRAFFIC STATION FOUND".

Viewing Messages

When MSG appears on the radio display, a new message is available for viewing. These messages are from the RDS broadcaster and may be general information such as artist and song title. To view the text message, press the MSG button. If the whole message does not appear on the display, parts of the message will appear every three seconds until the message is completed. To view the message faster, press the MSG button again.

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 broadcast once a minute. To set the clock press the RDS SELECT button. Then press and hold either the HR or MN button. If the broadcaster is sending clock time data the display should show "STATION TIME IS xx:xx". If the time is acceptable, simply continue to press and hold the HR or MN button until the display shows "TIME UPDATED".

Steering Wheel Controls

Some audio functions are available using the steering wheel controls. The steering wheel controls consist of multiple momentary contact switches that connect a series of resistors. When a switch is pressed, a voltage drop occurs in the resistor network, which produces a specific voltage value unique to the switch selected. These specific voltage values allow the CD changer or body control module (BCM) to identify which switch has been pressed. Class 2 messages are then sent from the CD changer or BCM to the appropriate component to perform the desired function.

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 CD changer for routing to the audio amplifier.

Viewing Messages

Press the MSG button while in XM mode to view various pieces of information related to the current song or channel. By pressing and releasing the MSG button, 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. If an Additional Information message is being broadcast on the tuned channel, MSG will appear on the display. Each of the four information types may have multiple pages of text. To reach a category, press and release the MSG button 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 MSG button to review all of the pages at your own pace.

Selecting a PTY

The LEVEL + or -- buttons can be used to scroll through the list of available program types (PTY). Press the PTY button, followed by the LEVEL + or -- buttons to scroll through the available program types. When the desired PTY is shown on the display, press the TUNE/SEEK or SCAN button twice. 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