GM Service Manual Online
For 1990-2009 cars only

Radio/Audio System Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

  1. Turn the ignition switch to the ON position.
  2. Ensure that the radio is OFF.

The radio displays the current time.

Radio Display Inoperative, No Sound from Speakers

2

Turn the radio ON.

The radio displays a current station for approximately 5 seconds and then the current time.

Radio Display Inoperative, No Sound from Speakers

3

Turn the headlamp switch to the PARK position.

    • The radio display dims.
    • The radio face and buttons illuminate.

Interior Lights Dimming System Check

4

  1. Turn the FADE control to the front speakers.
  2. Turn the balance control to the left front speaker and then to the right front speaker.
    • Only the front speakers are heard.
    • Only the left front and then the right front speakers are heard.
    •  Radio Poor Reception

5

  1. Turn the FADE control to the rear speakers.
  2. Turn the balance control to the left rear speaker and then to the right rear speaker.
  3. Return the fade and balance control to the neutral position.
    • Only the rear speakers are heard.
    • Only the left front speakers and then the right front speakers are heard.
    •  Radio Poor Reception

6

Press the RECALL button.

The radio display toggles between the tuner and the clock.

Radio Control Inoperative,

refer to Radio Replacement

7

Adjust BASS control to the high and low position.

The music attenuates between high and low bass frequencies.

Radio Control Inoperative,

refer to Radio Replacement

8

Adjust TREB control to the high and low position.

The music attenuates between high and low treble frequencies.

Radio Control Inoperative,

refer to Radio Replacement

9

Return BASS and TREB control buttons to the neutral position.

The music returns to nominal bass and treble frequencies.

Radio Control Inoperative,

refer to Radio Replacement

10

Press the AUTO TONE button 7 times.

Auto tone cycles through the following presets:

    • C/W
    • CLASSIC
    • NEWS
    • ROCK
    • POP
    • JAZZ
    • OFF

Radio Control Inoperative,

refer to Radio Replacement

11

Press up the BAND button in order to access the FM1 and FM2 bands.

The radio stations on the FM1 and FM2 bands appear on the display.

Radio Control Inoperative,

refer to Radio Replacement

12

Press the BAND button down in order to access the AM band.

The radio stations on the AM band appear on the display.

Radio Control Inoperative,

refer to Radio Replacement

13

Press and hold the SCAN button for 2-3 seconds.

Each of the presets are scanned for a few seconds and continues until the button is pressed again.

Radio Control Inoperative,

refer to Radio Replacement

14

Press and hold HR or MIN until the time display begins to change.

The time display begins to move. There is approximately a 2 second delay before the clock goes into the time-set mode.

Radio Control Inoperative,

refer to Radio Replacement

15

Insert a known good cassette tape into the tape player.

The cassette tape plays and sound is heard from the speakers.

Tape Player Control Inoperative, refer to Radio Replacement

16

    • Press the NEXT or SEEK UP button.
    • Press the PREV or SEEK DOWN button.
    • The cassette tape moves to next selection and plays.
    • The cassette tape moves to previous selection and plays.

Tape Player Control Inoperative, refer to Radio Replacement

17

Press the FWD button.

The cassette tape will fast forward and then reverse.

Tape Player Control Inoperative, refer to Radio Replacement

18

Press the REV button.

The cassette tape will reverse.

Tape Player Control Inoperative, refer to Radio Replacement

19

Press the AM/FM button.

Sound toggles from the cassette tape player to the radio tuner.

Tape Player Control Inoperative, refer to Radio Replacement

20

Press the EJECT button.

The cassette tape player will eject tape.

Tape Player Control Inoperative, refer to Radio Replacement

21

Insert a known good compact disc (CD) (w/signal disc CD player).

The CD plays and sound is heard from the speakers.

    • CD Player Control Inoperative, refer to Radio Replacement

22

Press the TUNE-SEEK button.

The CD moves to the next selection and plays.

CD Player Control Inoperative, refer to Radio Replacement

23

    • Press and hold the FF button.
    • Press and hold the RW button.
    • The CD fast forwards.
    • The CD reverses.

CD Player Control Inoperative, refer to Radio Replacement

24

    • Press the AM/FM button.
    • Press the CD/AUX button.
    • Press the SOURCE button
    • Sound toggles between the CD player and the radio tuner.
    • Sound toggles back to the CD player.
    • The CD player ejects the CD.

CD Player Control Inoperative, refer to Radio Replacement

25

  1. Ensure that the compact disc (CD) player is loaded and installed (w/12 disc CD player).
  2. Press the SOURCE button.

The CD player plays and sound is heard from the speakers.

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