GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

Schematic Reference: Radio/Audio System Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Turn ON the ignition, with the engine OFF.
  2. Operate the radio using the steering wheel controls (SWC).

Does the radio operate normally with the steering wheel controls?

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

Go to Step 3

3

    Caution: Refer to SIR Caution in the Preface section.

  1. Disable the SIR. Refer to SIR Disabling and Enabling in SIR.
  2. Remove the SIR assembly to expose the steering wheel controls (SWC) connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Test the retained accessory power (RAP) fuse supply voltage circuit of the SWC connector for an open.

Did you find and correct the condition?

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Go to Step 10

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Measure the resistance between the RAP fuse supply voltage circuit and the steering wheel controls signal circuit of the SWC connector attached to the SWC switches.
  3. Depress the following steering controls and record the resistance values.
  4. • Volume Up
    • Volume Down
    • Mute
    • Seek Up
    • Seek Down
    • Preset

Do the recorded values measure near the specified values?

1270 ohms

294 ohms

823 ohms

715 ohms

1180 ohms

9350 ohms

Go to Step 5

Go to Step 7

5

  1. Turn OFF the ignition.
  2. Disconnect the body control module (BCM) connector with the Steering Wheel Controls circuit.
  3. Test the steering wheel controls signal circuit for a short, high resistance or an open.

Did you find and correct the condition?

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Go to Step 10

Go to Step 6

6

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

Did you find and correct the condition?

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Go to Step 10

Go to Step 9

7

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

Did you find and correct the condition?

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Go to Step 10

Go to Step 8

8

Replace the appropriate SWC switch. Refer to Steering Wheel Control Switch Assembly Replacement in Steering Wheel and Column.

Did you complete the replacement?

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Go to Step 10

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9

Replace the radio. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

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Go to Step 10

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10

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2