GM Service Manual Online
For 1990-2009 cars only

The radio is located in the center of the instrument panel. It provides all customer interface to the radio and cassette player or compact disc (CD) changer functions. All radios incorporate electronic memory for the pre-selected stations function. The pre-selected stations must be reset whenever the vehicle battery is disconnected or power is otherwise lost to the radio.

Backlighting is provided by incandescent bulbs controlled by an external dim knob on the instrument panel.

The vacuum fluorescent (VF) display indicates the time of day, radio frequency or CD track information.

The radio controls operate as follows:

ON/OFF: Press the volume knob for ON and OFF.

VOLUME: The volume is controlled with this knob. Clockwise equals louder; counter-clockwise equals less volume. The volume knob is designed to rotate infinitely.

FADE: Lightly press the fade control dial. Rotating it clockwise moves the sound to the front speakers; rotating it counter-clockwise moves the sound to the rear speakers.

DSPL: Press the DSPL button to recall time of day.

TUNE-SEEK: Press TUNE/SEEK button until you hear a chime to to tune the radio to the next higher or lower frequency. If the button is held down for more than two seconds after the chime is heard, the radio operates in tune fast mode. Release the button to stay at a radio station.

AM: Press the AM button. The radio changes to the AM band.

FM1-2: Press the FM1-2 button to select between FM1 band and FM2 band.

SCAN: Press the SCAN button. The SCAN indicator in the display lights and the radio finds the next station and stays there for a few seconds; the radio goes to the next station and stays there for a few seconds. The radio goes to the next station and pauses, and so on. To stop scanning, press SCAN again

CLOCK: To set the clock, press and hold the H or M button until the clock begins to change. Release the button as the display gets close to the correct time. Note that there is an initial two-second delay before the clock begins time-set mode. The clock stays on the display continuously.

TIME OF DAY: The time of day is maintained by a real time clock internal to the dash integration module (DIM). This time of day is broadcast as a Class 2 message over the serial data line. The radio receives this data and displays it on the front panel. Changing the time of day is accomplished through the hour and minute buttons on the front of the radio. These button presses are translated by the radio which then sends a Class 2 message to the DIM requesting a change in the time. The radio itself does not maintain the time.

PRESET STATIONS: The six buttons let you return to favorite stations. You can set pushbuttons for up to 18 stations (six AM, six FM1 and six FM2). Select the band that you want, tune to desired station, press and hold one of the six buttons that you want station set to until you hear a chime and the display channel number and audio returns. Holding button for longer than two seconds activates fast seek mode.

PSCAN: Any station already set up on the preset buttons can be sampled using PSCAN (preset scan). Press the SCAN button and hold for 2-3 seconds or until the display shows PSCAN. It scans each of the presets and stops for a few seconds at each station. The tuner continues scanning until you press scan again. PSCAN is displayed whenever the tuner is in PSCAN mode.

DSP: The digital signal processing (DSP) feature allows you to tailor the equalization to the type of music or voice heard on the radio, cassette tape and compact disc (CD) player. Press this button to go through the four equalization settings of TALK, FRONT SEAT, AMBIENCE and SPACIOUS. The corresponding word appears on the display each time the button is pressed. DSP also appears on the display when in this mode. Press OFF on the DSP button to turn DSP off.

LEVEL: Press the plus or minus symbol on this button to adjust the amount of effect desired when in DSP mode.

STEERING WHEEL CONTROLS: In vehicles with steering wheel controls, pressing the VOLUME control increases or decrease the volume. Pressing the SELECT control toggles through the presets 1 through 6 in AM, FM1, and FM2 depending which band is currently being used.

AUTO VOLUME CONTROL: The system has a feature called automatic volume control (AVC). With AVC, the audio system monitors the noise in the vehicle. AVC automatically adjusts the volume level so it always sounds the same to you. To use AVC, press and hold the TONE button until AUTO VOLUME CONTROL OFF appears on the display. Press the LEVEL plus (+) symbol. AUTO VOLUME CONTROL ON appears on the display anytime you adjust the volume while AVC is on. To turn AVC off, press and hold the TONE button until AUTO VOLUME CONTROL ON appears on the display. Press the LEVEL minus (-) symbol. AUTO VOLUME CONTROL OFF appears on the display.

EJECT: Eject a cassette tape by depressing the EJECT button, even when the ignition switch is OFF.