The following is included in each audio system:

The Electronically Tuned Receiver (ETR) utilizes a programmer and synthesizer to provide optimum sound reproduction. The ETR incorporates an electronic memory for preselected station and digital clock function. Reset the memory whenever the battery is disconnected.

Each system has a vacuum fluorescent (VF) display that coordinates with the other instrument panel (I/P) displays. The Body Control Module (BCM) controls the dimming of the display based on inputs from the I/P cluster which reads adjustments of the I/P cluster dimmer switch (rheostat). The Light Emitting Diode (LED) and the back lighting of the radio face is done with incandescent light powered directly by the I/P cluster dimmer switch (rheostat).

The range of most Amplitude Modulation (AM) stations is greater than FM stations. This is especially true at night. The AM band tuning range is 530 kHz to 1710 kHz.

The Delco-GM/BOSE® audio system is an advanced automotive sound system that is tuned to the interior of the vehicle. The six speakers in four locations, two amplifiers in the forward speaker locations, and an amplifier incorporated into a signal processor are designed to deliver acoustically customized sound. The following are considered in the customization of the sound:

The result is a carefully calculated distribution of sound. The sound does not seem to come only from the speaker which results in a resemblance of a live concert performance.

When the system is turned ON the Bose® relay is energized through the radio receiver. The relay contacts close and apply current from the Bose® fuse to the two door mounted speaker/amplifier assemblies. This causes a slight delay from the time the system is turned on, until the sound is heard.

Loud bass volume is possible while maintaining sound clarity. Both forward speaker assemblies contain a specially designed amplifier and woofer (speaker) to assure clear sound reproduction at high volume levels. The following are some features of the system:

The Compact Disc (CD) player provides exceptional clarity and provides low background noise through digital reproduction. A selectable audio compression circuit processes the audio signal. This processed audio signal brings quiet and loud music passages into a more desirable listening range. This is especially useful in the automotive environment. When using compression, a demanding recording can be listened to without continually adjusting the volume.

The automotive environment can be a difficult one for sophisticated electronics. The CD player design takes into account many of the problems seen in automobiles. The player is designed to protect its optics from humidity and from excessive heat by automatically shutting down and ejecting the disc or displaying ERR. A special nylon filter across the disc opening protects the disc mechanism's optics from interference caused by moisture, dust and sunlight.

The loading system gently draws the disc into the mechanism. An ejected disc extends out almost halfway allowing the user to easily manage the disc. The loading system prevents damage to the disc if insertion of a second disc is attempted.

The use of a laser beam to read digital information means the disc will rarely wear out. There is no physical contact with the disc. An occasional skip due to rough roads will not damage the disc.

The remote compact disc (CD) changer is available with either the UL0 or the UN0. The remote (CD) changer is located in the cargo area in the center storage compartment. This CD changer features a 12 disc, removable magazine, and operation through the radio control head. The CD changer includes many of the quality design components found in the I/P mounted CD player (UN0).

(Convertible Models have a Power Antenna)

The Corvette Coupe features a diversity antenna system designed to deliver the best radio signal reception possible.

Two antennas are used to form a diversity system. The primary antenna is attached to the rear lift window similar to a defogger grid. This antenna is used to receive both AM and FM signals. The secondary antenna is attached to the windshield in the same manner as the primary antenna. This antenna is used to receive only FM (diversity) signals. The antenna reception signals are sorted by a reception processing module. The module then sends the clearest, strongest signal to the radio control.

Multipath or signal flutter is the quickly fading in and out of FM radio signal reception. Multipath or signal flutter most often occurs in down-town areas or wherever large obstructions are present. A radio signal reflects off of buildings at various angles. When one signal crosses paths with a same signal (at a different angle) they will cancel each other out. The signal will be received and then not received very rapidly by a vehicle audio system. This causes a fluttering effect to be heard through a vehicle's speakers. With the Corvette diversity antenna system one of the two antennas will virtually always receive a strong signal and widely limit mutipath.

Corvette radios come with the THEFTLOCK® radio security system. THEFTLOCK® is designed to discourage theft of the radio by using a secret code to disable all radio functions whenever battery power is removed.

The radio feature THEFTLOCK® may be used or ignored. If ignored, the system plays normally and the radio is not protected by this feature. If THEFTLOCK® is activated, the radio will not operate if stolen.

When THEFTLOCK® is activated, the radio will display LOC to indicate a locked condition anytime battery power is removed. If the system loses battery power for any reason the radio must be unlocked with the secret code before it will operate.

The system will turn ON with a momentary delay with the ignition in the ON or in the ACCESSORY position and rotating the upper knob clockwise. The station frequency is displayed and then the time of day is displayed. Rotate the knob clockwise to increase the volume. Rotate the knob counterclockwise to decrease the volume.

When the system is ON pressing RECALL will display (or recall) the station being played. When the ignition is OFF pressing RECALL will display the time of day.

The SCV (Speed-Compensated Volume) ring is located behind the PWR-VOL control knob. Rotating the ring up or down will automatically cause the volume to raise and lower as the speed of the vehicle increases and decreases. The top position has a higher maximum volume. The top position gets louder faster than the lower positions. When the system is ON the SCV will display. Rotating the ring all the way down will turn the SCV system OFF. Subtle changes in volume should not be noticeable to the driver when the system is working properly.

Push the BASS Control knob to release it. Rotate the knob to the right to increase bass. Rotate the knob to the left to decrease bass. Push the knob back in to store it when not adjusting.

Push the TREB knob to release it. Rotate the knob to the right to increase treble. Rotate the knob to the left to decrease treble. Push the knob back in to store it when not adjusting.

Push the BAL Control knob to release it. Rotate the knob to move sound between the right and left speakers. Push the knob back in to store it when not adjusting.

Push the FADE Control knob to release it. Rotate the knob to move sound between the front and the rear speakers. Push the knob back in to store it when not adjusting.

Push the TUNE Control knob to release it. Rotate the knob to choose desired radio stations. Push the knob back in to store it when not adjusting.

Press SEEK > or < SEEK and the radio will tune to the next higher or the next lower station and stay there.

Press AM/FM to receive AM, FM1, or FM2 band. The selection will appear on the VF display.

Press P SCAN to hear each of the present stations for a few seconds. Press P SCAN again to stop at a chosen station.

Press AUTO TONE to choose preset treble and bass equalization settings designed for one of the following:

Each time AUTO TONE is pressed, another setting will appear on the display. When MAN (manual) appears the control of the tone will be back to the treble and bass knobs.

ST will appear on the VF display whenever a FM stereo broadcast is selected.

A total of 18 stations can be preset. Six AM stations can be preset. Six FM1 stations can be preset. Six FM2 stations can be preset. The following is the preset stations procedure:

1. Tune in the desired station (in the desired band; AM, FM1, or FM2).
2. Press and hold one of the six push buttons for 5 seconds. The station will fade out and then return when set. The present station will return whenever that button is pressed.

Repeat these steps for each push button.

The time will appear on the VF display. To set the time perform the following procedure:

1. Press and hold HR (hour) until the correct hour appears.
2. Press and hold MIN (minute) until the correct minute appears.

There will be a 2-second delay before the clock goes into the time set mode.

Press RECALL to display the time when the ignition is OFF.

This cassette tape player is designed to work best with tapes that are 30 minutes long on each side. Longer tapes are much thinner. Thinner tape may not work well in this player.

This tape player has an automatic reverse feature. The automatic reverse feature automatically reverses the tape direction at the end of a side. Pressing PROG while the cassette tape is playing will reverse the tape direction.

To play a cassette tape perform the following procedure:

1. The ignition must be in the ACCESSORY or ON position.
2. Turn ON the radio.
3. Insert the exposed tape side of the cassette tape squarely through the tape door. If the tape is not inserted squarely no sound or a garbled sound may be heard. Press EJECT to remove the tape if no sound or a garbled sound is heard. Reinsert the exposed tape side of the cassette tape squarely through the tape door.
4. The radio will automatically turn OFF and the cassette tape will play. An arrow will appear in the VF display to indicate the direction of the play.

The following controls will function when a cassette tape is playing the same as they do during radio operation:

Refer to Radio/Audio System Operation - Radio Controls.

To stop play of a cassette tape perform one of the following:

Press FWD to rapidly advance the tape. Press FWD again to stop the tape advancing. The radio will play during this operation.

Press REV to rapidly reverse the tape. Press REV again to stop the tape reversing. The radio will play during this operation.

Press NEXT to play the next selection instead of waiting for the current selection to finish. For NEXT to work properly the tape must have at least three seconds of silence between each selection. The radio will pay during this operation.

Press PREV to replay the current selection. For PREV to work properly the tape must have at least three seconds of silence between each selection. The radio will play during this operation.

Press SEEK > to play the next selection instead of waiting for the current selection to finish. Press < SEEK to replay the current selection. The radio will play during these operations.

Press PROG to switch from one side of tape to the other side of tape. To reverse the direction of play.

Press AM/FM to stop cassette play and switch to radio.

Press TAPE AUX to stop cassette play and switch to radio. If the remote compact disc changer (U1S) is included in the vehicle sound system, pressing TAPE AUX a second time will allow it to play.

Press Dolby® to reduce background noise. The Dolby® symbol will appear in the VF display.

Press EJECT to remove cassette from the player. The radio will then play (when the power is on). EJECT will work with the ignition ON or OFF.

This message may appear on the VF display. If it does appear on the VF display the cassette player needs to be cleaned. Clean the player as soon as possible to help prevent permanent damage to tapes and to the player itself. Refer to Cassette Player Care and Cleaning .

To reset the CLN indicator after the player has been cleaned perform the following procedure:

1. Press and hold EJECT for five seconds.
2. "---" will appear on the VF display to verify that the indicator is reset.

This compact disc (CD) player is designed to use 120 mm (4.75 in) full size compact discs. If a 80 mm (3.14 in) single mini disc is inserted the disc will not be able to be ejected.

To play a compact disc (CD) perform the following procedure:

1. Turn the ignition to the ACCESSORY or the ON position.
2. Turn ON the radio.
3. Remove the compact disc from the case.



4. Insert the disc partway into the slot with the LABEL SIDE UP. The player will pull the disc in automatically. If the disc is upside down, dirty, scratched or wet, the player will eject it and ERR will appear on the VF display.
5. When successfully inserted, track 1 will begin to play. If the ignition or the power was turned OFF and a disc was left in the player the play will resume where it stopped. The following will appear on the VF display when a track begins:

•	CD will display (CD will appear on the display as long as a disc is in the player).

•	The disc icon will display.

•	The number of the track being played will display.

Once a disc is playing the following controls will function as they do during radio operation:

Refer to Radio/Audio System Operation - Radio Controls.

To stop play of a compact disc (CD) perform one of the following:

Press RECALL to display the number of the track currently playing. Press again within five seconds to display elapsed time (how long disc has been playing).

Press and hold FWD to rapidly advance within a track. Release it to resume playing.

Press and hold REV to rapidly reverse within a track. Release it to resume playing.

Press NEXT to hear the next track (instead of waiting for the current track to finish). If NEXT is held or pressed more than once the play will advance further.

Press PREV to replay the current track (selection). If held or pressed more than once the previous track will be played.

Press PREV within eight seconds of play from the beginning of the current track and the previous track will be played.

Press RDM to hear random order of tracks played. When the final random track has been played the same random selection will be played again. Press RDM while random selection is playing to return to normal sequence. The sequence will being playing in order of the current track playing when button was pressed. If RDM is pressed again a different random selection of tracks will play.

Press COMP to bring loud and soft sound into more desirable range (more nearly equal in volume). Press COMP again to return to normal function.

Press AM/FM to stop disc play and switch to radio. The disc icon will go off the VF display.

Press CD AUX to stop radio play and switch to disc play. Press TAPE AUX to switch back to playing tape.

If the remote compact disc changer (U1S) is included in the vehicle sound system, pressing TAPE AUX a second time will allow it to play.

Press EJECT to remove CD from player. EJECT will operate whether the power is ON or OFF. The radio will then play when the power is ON.

If EJECT is pressed but the disc not removed, the disc will be drawn back into the player (for protection) in approximately one minute.

Under certain conditions ERR will appear on the VF display. The following can cause an ERR message to display:

Perform the following to reset the ERR indicator:

Press RECALL to clear ERR indicator from the VF display.

The disc icon appears on the VF display of the radio control whenever a magazine containing discs is loaded into the changer. The disc icon will flash while the player is checking for discs. The CD disc icon is located in the bottom left corner. The following appears on the display when a disc begins playing:

Perform the following to play a compact disc in the remote CD changer:

1. Load discs into the magazine. Refer to Radio/Audio System Operation - Compact Disc Player (Remote Changer Magazine).
2. Insert the magazine into the CD player. Refer to Radio/Audio System Operation - Compact Disc Player (Remote Changer Magazine).
3. Turn the ignition to the ACCESSORY or ON position.
4. Turn ON the radio.
5. If radio is playing, press TAPE AUX (UL0) or CD AUX (UN0) to switch from radio play to playing a compact disc in the remote CD changer.
6. If cassette tape is playing, press TAPE AUX to switch from cassette play to playing a compact disc in the remote CD changer.
7. If the compact disc is playing (in the radio control UN0), press CD AUX to switch from compact disc play (UN0) to playing a compact disc in the remote CD changer.

The following controls will function as they do during radio operation once a disc is playing:

Refer to Radio/Audio System Operation - Radio Controls.

Perform any one of the following procedures to stop play of a compact disc (CD) in the remote CD changer:

TAPE AUX (Remote CD) Control

CD AUX (Remote CD) Control

Press PREV to replay current track (on the same disc).

Press PROG to select the next available disc in the magazine. The disc number appears on the VF display. If one of the discs cannot be played, that number will be skipped on the display.

Press NEXT to advance to the next track (on the same disc).

Press and hold FWD to rapidly advance through a track. The elapsed time will appear on the display.

Press and hold REV to rapidly reverse through a track. The elapsed time will appear on the display.

Press < SEEK to replay the current track once more than eight seconds have played. Press < SEEK 2 times to play the previous track. Press SEEK > to advance to the next highest track on the disc.

Press P SCAN to enter the random play mode. RANDOM appears on the VF display. The tracks on all loaded discs play in random order. Press SEEK while RANDOM is displayed to randomly scan the discs and tracks.

Slide the door on the remote CD changer all the way open. The disc will automatically eject. Keep the door closed whenever possible to prevent dirt and dust from getting into the changer.

Important: 

Inserting Discs

Up to 12 discs can be loaded in the magazine. The discs are numbered from 1 to 12 starting with the bottom disc tray.

1. Hold down the magazine lock button (1) and pull the tray out by holding if from underneath. The tray will detach from the magazine. Do not drop the tray. Do not drop the disc.



2. Place one LABEL-SIDE DOWN disc (1) on the disc tray (2). Do not touch the surface of the disc. The disc will not play if loaded upside down.




Important: 

•	Align the tray with the right and left grooves to allow it to be inserted to the end. Do not bend the tray. Do not force the tray.

•	Always load 12 trays in the magazine to prevent loss or warping of trays.

•	The player cannot recognize whether the disc is set or not if the disc is loaded label-side up. NO error message will display. Be sure all discs are loaded LABEL-SIDE DOWN.

3. Insert the tray (1) horizontally along the right and left grooves of the magazine (2) until it clicks. The disc must not lift from the tray.

Inserting Magazine

1. Slide the door on the remote CD changer open completely until it locks with a click.




Important: 

•	You must load the magazine with discs before inserting into player.

•	You must insert the magazine in the direction of the arrow (1). Be sure the arrow (1) is facing upward.

•	Completely remove the label on the magazine if it is coming off or if it is wrinkled. A damaged label may in-turn damage the eject mechanism. The eject mechanism may not eject the magazine.

2. Insert the magazine into the player in the direction of the arrow (1) on top of the magazine.



3. Slide the door all the way to the left to close. The player begins checking for discs in the magazine once the door is closed. This continues for up to 1-1/2 minutes depending on the number of discs loaded.

An error will occur and the changer will not operate if the door is left partially open.

To eject the magazine from the changer, refer to Radio/Audio System Operation - Compact Disc Player.

The following instructions explain how to enter a secret code to activate the THEFTLOCK™ system.

Read all nine steps before starting the procedure.

Important: If more than 15 SECONDS is allowed to elapse between any steps, the radio automatically reverts to displaying time and the procedure must be started over at Step 4.

1. Write down any three or four-digit number from 000 to 1999. Keep the number in a safe place separate from the vehicle. This number is the secret code.
2. Turn the ignition to the ACCESSORY or ON position.
3. Turn the radio OFF.
4. Press the number 1 and 4 push buttons at the same time. Hold the number 1 and 4 push buttons down until "- - -" appears on the VF display.
5. Press MN.

000 will appear on the display.

6. Press MN again until the last two digits agree with the last two digits of the secret code.
7. Press HR until the first one or two digits agree with the first one or two digits of the secret code.
8. Press AM/FM after confirming that the display code matches the secret code. REP appears on the display indicating that steps 5 through step 7 need to be repeated to confirm the secret code.
9. Press AM/FM again. SEC appears on the display indicating that the radio is secure. The indicator light by the PWR-VOL control begins flashing when the ignition is turned off.

Enter the secret code as follows pausing no more than 15 seconds between steps:

1. Turn the ignition to the ACCESSORY or ON position.
2. Turn the radio OFF.
3. Press the number 1 and 4 push buttons at the same time. Hold the number 1 and 4 push buttons down until SEC appears on the VF display.
4. Press MN.

000 will appear on the display.

5. Press MN again until the last two digits agree with the last two digits of the secret code.
6. Press HR until the first one or two digits agree with the first one or two digits of the secret code.
7. Press AM/FM after confirming that the display code matches the secret code. "- - -" appears on the display indicating that the radio is no longer secured.

SEC appears if the code is incorrectly entered. The radio will remain secured until the correct code is entered.

When battery power is supplied to a secured radio, the radio will not turn ON and LOC will appear on the display.

Enter the secret code as follows pausing no more than 15 seconds between steps:

1. LOC appears on the VF display with the ignition ON.
2. Press MN.

000 will appear on the display.

3. Press MN again until the last two digits agree with the last two digits of the secret code.
4. Press HR until the first one or two digits agree with the first one or two digits of the secret code.
5. Press AM/FM after confirming that the display code matches the secret code. SEC appears on the display indicating that the radio is now operable and secure.

INOP appears on the display if a wrong code is entered after eight attempts to enter the correct code. Wait one hour with the ignition ON before trying again. Only three attempts are allowed when retrying to enter the correct code before INOP appears.

Important: In order to display this code the radio should be in LOC mode or have SEC displayed before proceeding. Pause no more than 15 seconds between steps:

1. Press and hold push button numbers 2 and 3 for about 6 seconds until the first 3 digits of the display code appear.
2. Write the numbers down.
3. Press AM/FM to display the second set of 3 digits.
4. Write the numbers down.

After approximately 5 seconds, or if another button is pressed, the display returns to LOC. The display code must be unscrambled to get the factory backup code which unlocks the radio. Refer to Radio Theft-Deterrent, Factory Backup Code.

If the security is activated and the radio is disconnected from battery power, the radio will display LOC. The radio will not turn on until the correct unlocking code is entered. If the customer code is lost or unavailable, refer to the Dealer Communications System bulletin about the unlock procedure.

Important: The radio must be unlocked and no owners code can be currently stored in the radio to change the owners code. The radio will display 1:00 when unlocked. To determine whether or not there is an owners code stored press and hold push button numbers 1 and 4 until the display changes. If SEC is displayed there is an owners code stored. If "- - -" is displayed there is no code stored.

To Remove Owner's Code

(To Deactivate the Theft-Deterrent From the Unlocked Mode, Deterrent Activated):

Important: Either the owners code or the factory backup code can be used to remove the owners code.

Important: The theft-deterrent is already deactivated and no code is stored if the display changes to "- - -".

1. Turn the radio OFF. Press and hold push button numbers 1 and 4 for about 6 seconds until the display changes to read SEC.
2. Press HR to set the first two digits (0-19) of the code.
3. Press MN to set the next two digits (0-99) of the code.
4. Press the AM/FM button to enter the code.

Theft-Deterrent is deactivated when "- - -" appears on the display and then the time of day displays.

To Add Owner's Code

(To set the User Code (Activate) From the Unlocked Mode, Deterrent Deactivated):

Important: If SEC displays, the theft-deterrent is already activated. This means the old code must be removed before entering a new code.

1. Turn the radio OFF. Press and hold push button numbers 1 and 4 for about 6 seconds until the display changes to "- - -".
2. Press HR to set the first two digits (0-19) of the code.
3. Press MN to set the next two digits (0-99) of the code.

Important: If "- - -" displays after pressing AM/FM, the owners code has not been entered.

4. Press the AM/FM button to enter the code.
5. When REP then 000 are displayed, repeat steps 2 through step 4. This confirms the owners code and activates the theft-deterrent. SEC appears on the display indicating that the theft-deterrent is active, then the time of day appears on the display.

Anytime battery power is cycled and ignition is applied the LOC appears on the display. The system locks. To unlock the system use the owners code or the factory backup code. Refer to Radio Theft-Deterrent Unlocking After Power Loss.