GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Schematic Reference: Radio/Audio System Schematics

1

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

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Go to Step  2

Go to Diagnostic System Check - Entertainment System

2

  1. Turn ON the ignition, with the engine OFF.
  2. Turn ON the radio.
  3. Operate all of the tailgate audio control buttons.

Do all of the tailgate audio control buttons operate properly?

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Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step  3

3

  1. Turn OFF the ignition.
  2. Disconnect the tailgate audio controls connector. Refer to Rear Quarter Audio Control Replacement for service procedure.
  3. Turn ON the ignition, with the engine OFF.
  4. Turn ON the radio.
  5. Measure the voltage from the remote radio control supply voltage circuit of the radio to a good ground.

Does the voltage measure near the specified value?

9.5 V

Go to Step 4

Go to Step  5

4

  1. Measure the resistance from the remote radio control supply voltage circuit of the tailgate audio controls and the steering wheel controls signal circuit of the tailgate audio controls.
  2. Press the following tailgate audio control buttons and record the resistance values:
  3. • Volume Up
    • Volume Down
    • Play
    • Mute
    • Seek Up
    • Seek Down
    • AM/FM
    • Pre-Set

Do the recorded resistances measure near the specified values?

1270 ohms

1564 ohms

1912 ohms

2387 ohms

3102 ohms

4282 ohms

6652 ohms

13,632 ohms

Go to Step  6

Go to Step  7

5

Test the remote radio control supply voltage circuit between the tailgate audio controls harness connector and the radio for an open, high resistance or short. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step  11

Go to Step  8

6

  1. Disconnect the radio connector. Refer to Radio Replacement for service procedure.
  2. Test the steering wheel controls signal circuit between the tailgate audio controls harness connector and the radio connector for an open, high resistance or short. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step  11

Go to Step  8

7

Inspect for poor connections at the harness connector of the tailgate audio controls. 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 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  10

9

Replace the tailgate audio controls. Refer to Rear Quarter Audio Control Replacement for service procedure.

Did you complete the replacement?

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Go to Step  11

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10

Important:: Perform the set up procedure for the radio.

Replace the radio. Refer to Radio 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

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