Cellular Telephone Conversation Partner Does Not Hear You

Cellular Telephone Conversation Partner Does Not Hear You

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 uses the microphone to allow driver communication with the cellular telephone. The cellular telephone is connected to the mobile telephone control module via Bluetooth.

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

Ignition ON, observe the scan tool Microphone Signal parameter. The reading should be between 2-5 V.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the B24 Cellular Phone Microphone.
2. Ignition OFF, test for less than 10 ohm between outer shield and ground.

• If greater than the specified range, test the outer shield circuit for an open/high resistance. If the circuit tests normal, replace the K82 Mobile Telephone Control Module.

3. Ignition OFF, test for less than 10 ohm between low reference circuit terminal 2 and ground.

• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K82 Mobile Telephone Control Module.

4. Ignition ON, test for 9-11 V between the signal circuit terminal 3 and ground.

• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K82 Mobile Telephone Control Module.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K82 Mobile Telephone Control Module.

5. If all circuits test normal, replace the B24 Cellular Phone Microphone.

Repair Instructions

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

Control Module References (Programming and Relearning)