Schematic Reference: OnStar Schematics

Connector End View Reference: Entertainment/Communication Connector End Views

DEFINITION: This procedure is for diagnosing problems during OnStar® audio following a button press from the OnStar® button assembly.

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

1. Turn the ignition ON, with the engine OFF.
2. Turn ON the radio.
3. Set volume to a comfortable level.
4. Press the OnStar® Center Call button.

Can the Connecting to OnStar message be heard playing through the audio system at all?

Go to Step 3

Go to Step 4

Test the remote radio audio output (-) circuit for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 11

Does the radio mute once the OnStar® Call Center button is pressed?

Go to Step 5

Go to Step 9

Is any distortion heard?

Go to Step 7

Go to Step 6

Test the remote radio left audio signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 7

Test the remote radio left audio signal circuit for an open or short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 8

8

Test the remote radio audio output (-) circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 13

Go to Step 11

1. Turn the ignition OFF.
2. Disconnect the vehicle communication interface module (VCIM) connector C2.
3. Turn the ignition ON, with the engine OFF.
4. Turn ON the radio.
5. Set volume to a comfortable level.
6. Using a fused jumper, short the cellular mute signal circuit to a good ground.

Does the radio mute?

Go to Step 13

Go to Step 10

Test the cellular mute signal circuit for an open.

Did you find and correct the condition?

Go to Step 14

Go to Step 12

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

Did you find and correct the condition?

Go to Step 14

Go to Step 13

Replace the radio. Refer to Radio Replacement .

Did you complete the repair?

Go to Step 14

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Important: Perform the OnStar® setup procedure.

Replace the VCIM. Refer to Communication Interface Module Replacement .

Did you complete the repair?

Go to Step 14

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Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2