GM Service Manual Online
For 1990-2009 cars only

Audio Too Loud at Low Settings U85

Step

Action

Value(s)

Yes

No

1

Did you perform the Radio/Audio System Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Radio/Audio System

2

  1. Turn ON the ignition, with the engine OFF.
  2. Turn ON the radio.
  3. Insert the tape or CD from the J 39916-A .

Adjust the volume to the lowest setting that can be heard. Is the lowest setting too loud ?

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Go to Step 3

Go to Audio System Troubleshooting Hints

3

  1. Install a scan tool.
  2. Turn ON the ignition with the engine OFF.
  3. With a scan tool, observe the audio power amplifier parameter in the system configuration data list.

Does the scan tool indicate that the audio power booster is not present?

--

Go to Step 5

Go to Step 4

4

Compare the volume to a similar vehicle with the same audio system.

Are both vehicles the same?

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System OK

Go to Step 7

5

Test the gain control signal circuit for an open or high resistance. Refer to Circuit Testing in Wiring Systems.

Did you find and correct the condition?

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Go to Step 11

Go to Step 6

6

  1. Turn OFF the ignition.
  2. Disconnect the audio power amplifier.
  3. Connect a 3 amp fused jumper between the gain control signal circuit and ground.
  4. Turn ON the ignition, with the engine OFF.

Does the scan tool indicate that the audio power amplifier is present?

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Go to Step 8

Go to Step 7

7

Inspect for poor connections at the harness connector of the radio. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 11

Go to Step 9

8

Inspect for poor connections at the harness connector of the audio power amplifier. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 10

9

Replace the radio and perform the set up procedure for the radio. Refer to Radio Replacement and Radio Setup for service procedures.

Did you complete the replacement?

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Go to Step 11

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10

Replace the audio power amplifier. Refer to Radio Speaker Amplifier Replacement for service procedure.

Did you complete the replacement?

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Go to Step 11

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11

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 3