Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B2485 04

Wireless Communication Antenna Circuit Open

Circuit/System Description

The Bluetooth ® antenna is a small fixed antenna connected directly to the telematics communication interface control module and is used to send and receive signals from a Bluetooth ® enabled cellular phone. The antenna utilizes no cabling and is not external to the vehicle.

Conditions for Running the DTC

•	Ignition ON.

•	Battery voltage must be between 9-16 V.

•	The telematics communication interface control module tests the antenna once every second.

Conditions for Setting the DTC

The telematics communication interface control module detects a short to ground or an open/high resistance in the Bluetooth ® antenna.

Actions Taken When the DTC Sets

•	The OnStar® status LED turns red.

•	Bluetooth ® functionality is disabled.

Conditions for Clearing the DTC

•	The condition responsible for setting the DTC no longer exists.

•	A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

Schematic Reference

OnStar Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

OnStar Description and Operation

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

1.	Verify the Bluetooth ® antenna is properly connected to the K73 telematics communication interface control module and is not damaged.

2.	If the antenna is disconnected or damaged, repair or replace as necessary.

3.	Ignition ON, verify the DTC B2485 is not set.

4.	If the DTC is set, replace the Bluetooth ® antenna. Clear the DTC and cycle the ignition OFF then back ON. If the DTC resets as current, replace the K73 telematics communication interface control module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Wireless Communication Interface Antenna Replacement

•	Control Module References for telematics communication interface control module replacement, setup, and programming