For 1990-2009 cars

### 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 provide an overview of each diagnostic category.

### DTC Descriptor

DTC B2485 02: Wireless Communication Antenna Circuit Short to Ground
DTC B2485 04: Wireless Communication Antenna Circuit Open

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Signal | B2485 02 | B2485 04 | -- | --

### 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 V and 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

LINK

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Cellular Telephone Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

### Circuit/System Testing

1. Ignition OFF, disconnect the antenna cable from the K82 Mobile Telephone Control Module and the T4S Wireless Communication Antenna.
2. Ignition ON, test for less than 0.3 V between the antenna cable center terminal and ground.

⇒ | If greater than the specified range, replace the antenna cable.

3. Ignition ON, test for less than 0.3 V between the antenna cable outer shield and ground.

⇒ | If greater than the specified range, replace the antenna cable.

4. Test for infinite resistance between the antenna cable center terminal and ground.

⇒ | If less than the specified range, replace the antenna cable.

5. Test for infinite resistance between the antenna cable outer shield and ground.

⇒ | If less than the specified range, replace the antenna cable.

6. Test for less than 5 Ω between the antenna cable center terminal from end to end.

⇒ | If greater than the specified range, replace the antenna cable.

7. Test for less than 5 Ω between the antenna cable outer shield from end to end.

⇒ | If greater than the specified range, replace the antenna cable.

8. Test for infinite resistance between the antenna cable outer shield and the center terminal.

⇒ | If less than the specified range, replace the antenna cable.

9. If the antenna cable test normal, replace the T4S Wireless Communication Antenna.
10. 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 K82 Mobile Telephone Control Module

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Link x Wireless Communication Antenna Replacement

• | Control Module References for mobile telephone control module replacement, setup, and programming