B2485

DTC B2485

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)provide an overview of each diagnostic category.

DTC Descriptors
DTC B2485 02
- Wireless Communication Antenna Circuit Short to Ground

DTC B2485 04
- Wireless Communication Antenna Circuit Open

Diagnostic Fault Information





Circuit/System Description

The Bluetooth antenna is a small fixed antenna connected directly to the mobile telephone control module and is used to send and receive signals from a Bluetooth enabled cellular phone. The antenna is external to the vehicle.

Conditions for Running the DTC

* The ignition is in OFF, ACCESSORY or RUN position.
* The system voltage is between 9-16 V.
* The mobile telephone control module tests the antenna once every second.

Conditions for Setting the DTC

B2485 02
* The signal voltage is less than 1 V.
* The above conditions must be met for 500 ms.

B2485 04
* The signal voltage is greater than 2 V.
* The above conditions must be met for 500 ms.

Action Taken When the DTC Sets

The Bluetooth communication can not be establish.

Conditions for Clearing the DTC

The DTC will become history when the condition for setting the DTC is no longer present.

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)

Circuit/System Testing

1. Replace the T4S Wireless Communication Antenna - Bluetooth.
2. Clear the DTCs and operate the vehicle within the conditions for running the DTC. Verify DTC B2485 does not set.

• If the DTC sets, replace the T4S Wireless Communication Antenna - Bluetooth.

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