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 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 SWC connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Test the steering wheel controls voltage supply 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 steering wheel controls voltage supply circuit and the remote radio control 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 SWC circuit.
  3. Test the remote radio control 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 BCM. 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?

--

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 BCM. Refer to Control Module References in Computer/Integrating System.

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