GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1999 🢒 Catera 🢒 Body and Accessories 🢒 Data Link Communications 🢒 Radio/Audio System Check
Table 1: System Performance Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1
  1. Turn the ignition switch to the ON position.
  2. Turn the radio ON.
  1. Radio displays a current station.
  2. Sound can be heard from all speakers.
  3. No noise in speakers.
  4. Radio has good reception.
  5. No distortion in speakers.
    • Radio does not display radio station (display is blank) and no sound from speakers. Refer to Radio Display Inoperative, No Sound from Speakers .
    • Radio display is operative but no sound from speakers (BOSE®). Refer to Speakers Inoperative - One or More .
    • Speakers are noisy and/or radio has poor reception. Refer to the System Performance Check table below.
    • Speakers have distortion. Refer to Audio Distortion - One or More Speakers .

2

Turn the headlamp switch to the PARK position.
    • The radio display dims.
    • The radio face and buttons illuminate.
    • The radio display does not dim.
    • The radio face and buttons do not illuminate. Refer to Radio Display and/or Buttons Do Not Illuminate .

3

Press and release the SPEAKER button until the desired balance and fade control is found.

After selecting balance or fade, press the plus or minus symbol on the LEVEL button to attain the amount of balance or fade.

  1. Adjust the fade control to the front speakers.
  2. Adjust the balance control to the left front and then to the right front speaker.
  1. Only the front speakers are heard.
  2. Only the left front and then the right front speakers are heard.
    • No sound from front speakers (BOSE®). Refer to Speakers Inoperative - One or More .
    • No sound from left front or right front speakers. Refer to Speakers Inoperative - One or More or Speakers Inoperative - One or More .

4
  1. Adjust the fade control to the rear speakers.
  2. Adjust the balance control to the left rear and then to the right rear speaker. Return the fade and balance control to the neutral position.
  1. Only the rear speakers are heard.
  2. Only the left front and then the right front speakers are heard.
    • No sound from front speakers (BOSE®). Refer to Speakers Inoperative - One or More .
    • No sound from left front or right front speakers. Refer to Speakers Inoperative - One or More or Speakers Inoperative - One or More .

5
  1. Return the fade control to the neutral position.
  2. Adjust the balance control to include both speakers on the left side then include both speakers on the right side. Return the balance control to the neutral position.
  1. Only the left side speakers are heard.
  2. Only the right side speakers are heard.
    • No sound from the left side speakers or the right side speakers are heard. Refer to Speakers Inoperative - One or More for BOSE®.
    • For base system. Refer to Speakers Inoperative - One or More .

6

Press the SOURCE button to switch between audio sources, such as the CD changer and the radio.

The radio switches to the other audio sources.

No response from radio when a button is adjusted or pressed. Refer to Radio Replacement

7
  1. Insert a known good cassette tape into the tape player.
  2. Press the SOURCE button and select the tape player.

Cassette tape plays and a good quality sound is heard from the speakers.

Cassette tape does not play or the sound is distorted. Refer to Tape Player Inoperative .

8
  1. Insert a known good CD into the CD player (Single disc CD player).
  2. Press the SOURCE button and select the CD player.

CD plays and a good quality sound is heard from the speakers.
    • CD does not play. Refer to Radio Replacement .
    • The sound is distorted. Refer to Compact Disc General Diagnosis

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

System Performance Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

Important: The purpose of the System Performance Check is to distinguish between noise or poor reception. Some noises induced into the system may not be audible but can cause poor reception.

1
  1. Turn ignition to the (I) position, radio on.
  2. Turn dial to (88-108 FM) (550-1600 AM).
  3. Count the number of valid radio stations the tuner stops at.
  4. Listen for various noise problems.
  5. Turn the Ignition to the On (II), engine Off position. Repeat turning the dial to the FM and AM stations.
  6. Start and leave the engine running. Repeat turning the dial to the FM and AM stations.
    • A certain number of radio stations will be received with no noise problems and the reception is good.
    • Sometimes the radio will stop at dead spots on the display where there is no audible information. These dead spots should not be counted as valid stations
    • Certain radio stations have noise problems. Continue with the table.
    • Radio has poor reception with no noise. Refer to Radio Poor Reception .

2

With the radio playing on a noisy station, slowly back the radio out from mounting position.

If a "sideway" noise is present, the noise will get quieter.

Sideway noise can be caused by the wiring or hoses behind or on top of the radio or antenna coax cable. Refer to Audio System Troubleshooting Hints .

3

With the radio playing on a noisy station, unplug the antenna from the back of the radio. (Customer complaint may be ignition noise on AM only.)

If "frontway" noise is present, the noise will be eliminated.

Frontway noise can be caused by poor antenna grounding, or poor radio case ground.

Perform the following:

  1. Antenna Diagnostic Check
  2. If the antenna system is OK and a noise is still present, refer to Audio System Troubleshooting Hints .

4

If the noise is not sideway or frontway and is still heard at minimum volume, then "backway" noise is present.

"Backway" noise may be related to other harnesses and could be intermittent depending on the component that is causing it.
    • Suppression can be installed at the source (as close as possible is preferable), the radio or both.
    • Pops are best suppressed with a capacitor.
    • Squeals and buzzes are best suppressed using filters.
    • Read the Important note below.

Refer to Audio System Troubleshooting Hints .

Important: Radio frequency interference (RFI) can cause fewer station reception in one of the three modes. This RFI can be caused by various vehicle components, which may cause the difference in reception. Check for components powered up in the three various key positions. This may eliminate engine running components, ignition on components, etc. For example, if the same number of stations are received with the engine running as when the engine was off, the components active with the engine running are not causing the interference.

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