Avalanche 2500 4WD V8-8.1L VIN G (2003)
The only way to unlock the radio is by using a scan tool. Always refer to the table to diagnose the "Theftlock" DTC for further information.
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.
To operate the Integral Multi Disc CD Changer in the single play mode, depress the "LOAD" button for less than 2 seconds, an audible "beep" can
then be heard. When the disc door opens the LED to the right of the disc door will first turn red then green to indicate the CD can be loaded. The radio
will also display the message "INSERT CD 1" and the changer will pull the disc into the play position. To operate the changer in the multi disc mode,
depress the "MODE" button for more than two seconds and the LED to the right of the disc door will first turn red then green to indicate CDs can be
loaded. The radio will also display the message "MULTI LOAD" to indicate the multi load mode has been initiated and the changer will begin
accepting a disc for however many empty slots there may be. If eight seconds elapse before the next disc is loaded, the multi load mode is cancelled
and can be re-initiated if desired by depressing the load button again for more than 2 seconds. If the changer is full, (six discs are loaded) the single
play and multi load modes cannot be executed. When this occurs, three audible beeps are heard and the message "CHANGER FULL" is displayed.
Remote Playback Device
The remote playback device is either installed at the factory or in some instances it is dealer installed. There are three types of remote playback
devices, a multi disc remote CD changer, a single disc CD player and a cassette player. All three devices have a wiring harness which plugs into the
back of the radio. The radio controls and communicates with the remote playback device through a Entertainment and Comfort (E&C) or Class 2
communication circuit.
Remote CD Changer (CDX)
The remote CD changer allows for multiple compact disks to be played continuously without having to manually change compact discs. Normal size
discs may be played using the slots supplied in the magazine. The magazine must first be loaded with discs before it can played. To load CD's, insert
the CD's from bottom to top, placing the discs in the magazine 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 magazine. Once
the discs are loaded into the magazine, push the magazine into the changer in the direction of the arrow marked on the magazine. When the CD
magazine is loaded, the changer will begin checking for discs in the magazine. This will continue for up to one and a half minutes, depending on the
number of discs loaded. To eject the magazine from the player, push the CD changer door. The door will open. Then press the eject button. NOTICE:
If the CD magazine fails to eject after the EJECT button has been pressed, do not attempt to pry the magazine from the CD changer. Whenever a CD
magazine with discs is loaded in the changer, the CD changer symbol will appear on the radio display. If the CD changer is checking the magazine for
CD's, the CD symbol will flash on the display until the changer is ready to play.
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:
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RDS functions are provided in the FM broadcast band only.
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RDS functions will only work with FM broadcast stations that are broadcasting RDS data.
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Not all FM Broadcast stations broadcast RDS data or offer all of the RDS services.
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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:
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The name of the station.
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The type of program.
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General information such as artist and song title, call in phone numbers, etc.
