GM Service Manual Online
For 1990-2009 cars only

Radio/Audio System Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

  1. Radio OFF.
  2. Turn the ignition switch ON.

Radio displays the current time.

2

Turn the radio on.

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

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

6

Depress the RECALL button.

Radio display toggles between the tuner and the clock.

Radio Control Inoperative

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

7

Adjust the BASS control to the high and the low positions.

Music attenuates between high and low bass frequencies.

Radio Control Inoperative

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

8

Adjust the TREB control to the high and the low positions.

Music attenuates between high and low treble frequencies.

Radio Control Inoperative

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

9

Return BASS and TREB control buttons to the neutral position.

Music returns to nominal bass and treble frequencies.

Radio Control Inoperative

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

10

Press the AUTO TONE button seven times.

Auto tone cycles through the following presets:

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

Radio Control Inoperative

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

11

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

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

Radio Control Inoperative

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

12

Press the BAND button down to access the AM band.

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

Radio Control Inoperative

    •  Radio Replacement
    •  Radio Replacement
    •  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

    •  Radio Replacement
    •  Radio Replacement
    •  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

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

15

Insert a known good cassette tape into the tape player.

Cassette tape plays and sound is heard from the speakers.

Tape Player Weak, Slow, or Garbled Output

Tape Player Inoperative refer to:

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

16

    • Press the NEXT or SEEK > button.
    • Press the PREV or < SEEK button.
    • Cassette tape moves to next selection and plays.
    • Cassette tape moves to previous selection and plays.

Tape Player Inoperative

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

17

Press the FWD button.

Cassette tape will fast forward and then reverse.

Tape Player Inoperative

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

18

Press the REV button.

Cassette tape will reverse.

Tape Player Inoperative

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

19

Press the AM/FM button.

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

Tape Player Inoperative

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

20

Press the EJECT button.

Cassette tape player will eject tape.

Tape Player Inoperative

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

21

Insert a known compact disc (CD) into the CD player.

CD plays and sound is heard from the speakers.

CD Player Inoperative

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

22

Press the TUNE-SEEK button.

CD moves to next selection and plays.

CD Player Inoperative

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

23

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

CD Player Inoperative

    •  Radio Replacement
    •  Radio Replacement
    •  Radio Replacement

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