Cellular Telephone Conversation Partner Cannot Be Heard

Cellular Telephone Conversation Partner Cannot Be Heard

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provides an overview of each diagnostic category.

Diagnostic Fault Information





Circuit/System Description

The mobile telephone control module sends the telephone call via a hardwired signal to the radio. The radio mutes the audio source and transmit the telephone call to the speakers.

Reference Information
Schematic Reference

OnStar Schematics (OnStar Schematics)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Cellular Telephone Description and Operation (Cellular Telephone)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning)for scan tool information

Circuit/System Verification

1. Ignition ON, radio ON, adjust the radio balance and fade to each speaker.

• If any speaker does not operate properly, refer to Speaker Malfunction (Speaker Malfunction).

2. Ignition ON, command the Audio Tone test ON and OFF with the scan tool. Verify that a test tone turns ON and OFF.

Circuit/System Testing

Note: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. Ignition OFF, disconnect the X1 connector at the K82 Mobile Telephone Control Module and the X1 connector at the A11 Radio.
2. Ignition ON, test for less than 0.3 V between the audio signal circuit terminal 6 X1 at the K82 Mobile Telephone Control Module and ground.

• If greater than the specified range, test the audio signal circuit for a short to voltage.

3. Ignition ON, test for less than 0.3 V between the audio signal circuit terminal 15 X1 at the K82 Mobile Telephone Control Module and ground.

• If greater than the specified range, test the audio signal circuit for a short to voltage.

4. Test for infinite resistance between the audio signal circuit terminal 6 X1 at the K82 Mobile Telephone Control Module and ground.

• If less than the specified range, test the audio signal circuit for a short to ground.

5. Test for infinite resistance between the audio signal circuit terminal 15 X1 at the K82 Mobile Telephone Control Module and ground.

• If less than the specified range, test the audio signal circuit for a short to ground.

6. Test for less than 5 ohm between the audio signal circuit terminal 6 X1 at the K82 Mobile Telephone Control Module and the audio signal circuit terminal 20 X1 at the A11 Radio.

• If greater than the specified range, test the audio signal circuit for an open/high resistance.

7. Test for less than 5 ohm between the audio signal circuit terminal 15 X1 at the K82 Mobile Telephone Control Module and the audio signal circuit terminal 6 X1 at the A11 Radio.

• If greater than the specified range, test the audio signal circuit for an open/high resistance.

8. Test for infinite resistance between the shield ground circuit terminal 5 X1 at the K82 Mobile Telephone Control Module and audio signal circuit terminal 6 X1 and the audio signal circuit terminal 15 X1.

• If less than the specified range, test short circuit between each signal circuit and the shield ground circuit.

9. If all circuits test normal, replace the K82 Mobile Telephone Control Module and verify that the customer concern is not still present.

• If the customer concern is still present, replace the A11 Radio.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Control Module References (Programming and Relearning)for mobile telephone control module replacement, setup, and programming