AM/FM Reception through Remote CD Changer (CDX)

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 an audio amplifier and/or rear seat audio (RSA).

The uplevel system differs from the base level system by providing the customer with enhanced audio system features. Some of those features may include the radio data system (RDS), extended range speakers, an audio amplifier, or an uplevel amplifier, RSA, video entertainment system and a remote playback device.

The following list shows the radios available for this vehicle:
- Uplevel Radio (U1N) - AM/FM Stereo, Cassette with Programmable Equalizer and RDS
- Uplevel Radio (U1P ) - AM/FM Stereo, CD with Programmable Equalizer and RDS
- Uplevel Radio (U1Q) - AM/FM Stereo, Cassette, CD with Programmable Equalizer, Rear Seat Audio (RSA) System and RDS
- Uplevel Radio (UC6) - AM/FM, Integral Multi Disc CD Changer (IMCX) with Programmable Equalizer, Rear Seat Audio (RSA) System and RDS

Radio Features - Part 1:

Radio Features - Part 2:

RADIO FEATURES

Cassette Features:

CASSETTE FEATURES

COMPACT DISC FEATURES

Compact Disc Features:

Each item in the list below represents topics covered in detail below.
- AM/FM Reception
- Antenna
- Audio Amplifier
- Theft Deterrent
- Integral Multi Disc CD Changer (IMDX)
- Remote Playback Device
- Rear Seat Audio (RSA)
- Radio Data System (RDS)
- Steering Wheel and Tailgate Audio Controls
- Tape/CD Player Error Messages

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:
- The power output, or 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 affected 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 Reception
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 areas. 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.

Antenna
The antenna is comprised of a very thin metal grid which is permanently affixed to the top center of the windshield. If the antenna becomes damaged, the windshield must be replaced.

Audio Amplifier
The purpose of an amplifier is to increase the power of a voltage or current signal. The output signal of an amplifier may consist of the same frequencies as the input signal or it may consist of only a portion of the frequencies of the input signal, as in the case of a subwoofer or a mid-range amplifier.

When the radio is turned on, the radio sends a voltage signal to the audio amplifier via the amplifier control circuit. The amplifier present signal circuit allows the radio to recognize that an amplifier is present. Once the radio detects the amplifier, the radio will output low level audio signals to the amplifier. With the amplifier enabled, the signal that drives the speakers is now amplified.

Theft Deterrent
The "Theftlock" 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, a DTC will set, the radio will not respond to any button presses and become inoperative. The 2 scenarios able to cause this condition are:
- A radio is installed from another vehicle
- 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. Always refer to the table in this section to diagnose the "Theftlock" DTC for further information.

Integral Multi Disc CD Changer (IMDX [Uplevel])
The Integral Multi Disc CD Changer has the capability of storing and playing up to 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 and release the LOAD button and wait for the LED to the right of the disc door to turn green. Load a disc when the LED turns green. If the radio is ON, the disc will begin to play automatically. If the radio is OFF, press the LOAD button for the disc to play.

Multi Disc Loading
To operate the Multi Disc CD Changer in the multi disc mode, press and hold the LOAD button for 2 seconds. An audible beep will be heard and the LED to the right of the disc door begins to flash. The radio will also display the message "INSERT CD". When the LED stops flashing and turns green, load a disc. Once the disc is loaded the LED begins to flash again. 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. When the LED stops flashing and turns green, load another disc. Repeat this procedure to continue loading discs. The CD changer holds up to 6 discs.

When the changer is full, 6 discs are loaded, and the LOAD button is pressed, 3 audible beeps are heard and the message "CHANGER FULL" is displayed.

To play one of the CD's, press one of the preset buttons.

Removing CDs
Use the eject button, the button labeled CD to remove a disc or discs.

Perform the following to eject:
- To remove a single disc, press and release the CD button. The message "REMOVE CD" is displayed.
- To remove multiple discs, press and release the CD button for 2 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.

IMPORTANT: Pressing the CD button repeatedly, causes the radio receiver's 25 second eject timer to reset at each press of the button. This will cause the receiver to not eject a disc until the 25 second time period has elapsed.

Song List Feature
The Multi Disc CD Changer has a feature called Song List. This feature is capable of saving 20 track selections to a play list.

To save tracks into Song List, perform the following :
1. The disc player must be ON with at least one disc loaded.
2. The message "S-LIST" should not be displayed on the radio. If "S-LIST" is present, press the SONG LIST button to turn it OFF.
3. Select the desired disc by pressing the numbered push-button and then use the SEEK right arrow button to locate the track that you want to save. The track will begin to play.
4. Press and hold the SONG LIST button for 2 or more seconds to save the track into memory. When SONG LIST is pressed an audible beep is heard. After 2 seconds of pressing SONG LIST continually, 2 audible beeps will sound to confirm that the track has been saved. The message "TRACK ADD" is displayed.
5. Repeat steps 3 and 4 for saving other selections.

To play the Song List press the SONG LIST button. One beep is heard and "S-LIST" appears on the display. The recorded tracks will begin to play in the order that they were saved.

To delete tracks from the Song List.
1. The disc player must be on.
2. Press the SONG LIST button. The message "S-LIST" appears on the display.
3. Press the SEEK button to locate desired track to be deleted.
4. Press and hold the SONG LIST button for 2 seconds. After 2 seconds, 2 beeps are heard confirming that the track has been deleted. The message "TRACK DELETE" is displayed.

To delete the entire Song List.
1. The disc player must be on.
2. Press the SONG LIST button. The message "S-LIST" appears on display.
3. Press the SEEK button to locate desired track to be deleted.
4. Press and hold the SONG LIST button for more than 4 seconds. After 2 seconds, a beep will be heard followed by 2 beeps and a final beep after 4 seconds. The message "S-LIST EMPTY" appears on the display.

Remote Playback Device
The remote playback device is either installed at the factory or in some instances it is dealer installed. There are 3 types of remote playback devices, a multi disc remote CD changer, a single disc CD player and a cassette player. All 3 devices have a wiring harness which plugs into the back of the radio. The radio controls and communicates with the remote playback device through an 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 CDs, insert the CDs 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 CDs, the CD symbol will flash on the display until the changer is ready to play.