B2485

DTC B2485 (with UE1)

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 (BT) Antenna Circuit Short to Ground

DTC B2485 04
- Wireless Communication (BT) Antenna Circuit Open

Diagnostic Fault Information






Circuit/System Description

The Bluetooth (R) 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 (R) enabled cellular phone. The antenna utilizes no cabling and is not 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 telematics communication interface 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.

Actions Taken When the DTC Sets

* The OnStar (R) status LED turns red.

* Bluetooth (R) 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.

Reference Information

Schematic Reference

OnStar Schematics OnStar Schematics

Connector End View Reference

Component Connector End Views A/C Compressor Clutch

Description and Operation

OnStar Description and Operation OnStar

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 Verification

1. Ignition ON.

2. Verify that DTC B2458 is not set.

• If DTC B2485 is set
Refer to Circuit/System testing

• If DTC B2485 is not set

3. All OK.

Circuit/System Testing

1. Verify that the T4S wireless communication antenna - Bluetooth (R) is properly connected to the K73 telematics communication interface control module and is not damaged.

• If the antenna is disconnected
Connect the T4S wireless communication antenna - Bluetooth (R) to the module.

• If the antenna is damaged
Test or replace the T4S wireless communication antenna - Bluetooth (R).

• If the antenna is connected and not damaged

2. Ignition ON.

3. Verify DTC B2485 is not set.

• If the DTC is set

1. Test or replace the T4S wireless communication antenna - Bluetooth (R).

2. Clear the DTC, ignition OFF.

3. Ignition ON.

4. Verify the DTC is not set.

• If the DTC is set, replace the K73 telematics communication interface control module.

• If the DTC is not set

5. All OK.

• If the DTC is not set

4. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Wireless Communication Interface Antenna Replacement Service and Repair

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