GM Service Manual Online
For 1990-2009 cars only

Radio/Audio System Diagnostic System Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

  1. Turn ignition switch to ON.
  2. Turn radio ON.
  3. Position tuner on a strong radio station
  4. Set volume to medium.

Radio display illuminates and sound is heard from speakers.

No Display, No Sound from Speakers.

2

  1. Turn the FADE button to front speakers and then to rear speakers.
  2. Return FADE button to the neutral position.
  1. Only front speakers are heard.
  2. Only rear speakers are heard.
  3. Front and rear speakers are heard.
    • One or More Speakers Inoperative (Front Subwoofers).
    • One or More Speakers Inoperative (Front Midrange Speakers).
    • One or More Speakers Inoperative (Rear Speakers).

3

  1. Turn the BAL button to left side speakers and then to right side speakers.
  2. Return BAL button to the neutral position.
  1. Only left side speakers are heard.
  2. Only right side speakers are heard.
  3. Left and right side speakers are heard.
    • One or More Speakers Inoperative (Front Subwoofers).
    • One or More Speakers Inoperative (Front Midrange Speakers).
    • One or More Speakers Inoperative (Rear Speakers).

4

  1. Depress the RECALL button.
  2. Adjust BASS button to the high and low position.
  3. Adjust TREB to the high and low position.
  4. Return BASS and TREB buttons to the neutral position.
  5. Depress the AUTO TONE button seven times.
  1. Radio display toggles between the tuner and the clock.
  2. Music attenuates between high and low bass frequencies.
  3. Music attenuates between high and low treble frequencies.
  4. Music returns to nominal bass and treble frequencies.
  5. Auto tone cycles through the following presets:
  6. • C/W
    • CLASSIC
    • NEWS
    • ROCK
    • POP
    • JAZZ
    • OFF

No response from radio when a button is adjusted or pressed (replace the radio).

5

Insert a known good cassette tape into the cassette player.

Cassette plays and sound is heard from speakers.

Tape Player Inoperative.

6

  1. Press the NEXT or SEEK> button.
  2. Press the PREV or <SEEK button.
  3. Press the FWD button.
  4. Press the REV button.
  5. Press the DOLBY® button ON and OFF.
  6. Press the AM/FM button.
  7. Press the TAPE/AUX button.
  8. Press the cassette EJECT button.
  1. Cassette moves to next selection and plays.
  2. Cassette moves to previous selection and plays.
  3. Cassette will fast forward.
  4. Cassette will reverse.
  5. Dolby® symbol on display will toggle ON/OFF.
  6. Sound will toggle between the radio tuner and the cassette player.
  7. Cassette player will eject tape.
    • Tape Player Inoperative.
    • No response from radio when a button is depressed (replace the radio).

7

(Single disc CD player) Insert a known good CD into the CD player.

CD plays and sound is heard from speakers.

Compact Disc Inoperative.

8

  1. Press the NEXT or SEEK> button.
  2. Press the PREV or <SEEK button.
  3. Press the FWD button.
  4. Press the REV button.
  5. Press the AM/FM button.
  6. Press the CD/AUX button.
  7. Press the CD EJECT button.
  1. CD moves to next selection and plays.
  2. CD moves to previous selection and plays.
  3. CD will fast forward.
  4. CD will reverse.
  5. Sound will toggle between the CD player and the radio tuner.
  6. Sound will toggle back to CD player.
  7. CD player will eject CD.
    • Compact Disc Inoperative.
    • No response from radio when a button is depressed (replace the radio).

9

  1. (12-disc remote CD player) Ensure that CD changer magazine is loaded and installed.
  2. Press the CD/AUX button.

Remote CD changer plays and sound is heard from speakers.

Remote CD Changer Is Inoperative.

10

  1. Press the NEXT or SEEK> button.
  2. Press the PREV or <SEEK button.
  3. Press the FWD button.
  4. Press the REV button.
  5. Press the AM/FM button.
  1. CD moves to next selection and plays.
  2. CD moves to previous selection and plays.
  3. CD will fast forward.
  4. CD will reverse.
  5. Sound will toggle between the CD player and the radio tuner.
    • Remote CD Changer Inoperative.
    • No response from radio when a button is depressed (replace the radio).

11

  1. Position the Speed Compensated Volume (SCV) control ring from OFF to position one.
  2. Drive the vehicle in varying stop and go conditions.
  3. Position the Speed Compensated Volume (SCV) control ring from position one to position two.
  4. Drive the vehicle in varying stop and go conditions.
  5. Position the Speed Compensated Volume (SCV) control ring from position two to position three.
  6. Drive the vehicle in varying stop and go conditions.
  1. Volume of radio increases mildly with a slight delay as vehicle accelerates.
  2. Volume of radio increases louder with a slight delay as vehicle accelerates.
  3. Volume of radio increases louder without a delay as vehicle accelerates.

Speed Compensated Volume does not work correctly (Go to Scan Tool Does Not Communicate w/Class 2 Data Line, see Data Link Connector Diagnostic Information and Procedures).

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.