B1259

DTC B1259

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.

DTC Descriptor
DTC B1259
^ Antenna Ground Circuit

Diagnostic Fault Information





Circuit/System Description

The antenna signal circuit is a coaxial cable that carries the radio signal information received by the antenna. The antenna cable also provides a path for D.C. current for powering the antenna.

Conditions for Running the DTC

This test is run every 300 milliseconds

Conditions for Setting the DTC

The DRR detects an antenna fault.

Action Taken When the DTC Sets

The radio displays "No XM Signal" or "Check Antenna"

Conditions for Clearing the DTC

* The condition must be corrected.
* The DTC clears after 100 malfunction-free ignition cycles.

Reference Information
Schematic Reference

Radio/Navigation System Schematics (Radio/Navigation System Schematics)
Connector End View Reference

Component Connector End Views (Component Connector End Views)
Description and Operation

Radio/Audio System Description and Operation (Radio/Audio System Description and Operation)
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)

Special Tools

EL-48028 Digital Radio Test Antenna

Circuit/System Testing

1. Ignition OFF, disconnect the digital radio receiver antenna coax. Connect the test antenna to the digital radio receiver.
2. Turn the ignition ON, radio ON tuned to XM. Verify that DTC B1259 is not current.

• If the DTC B1259 is still current, replace the DRR.

3. Ignition OFF. Disconnect the DRR antenna from the coaxial cable. Test the resistance of the antenna coaxial cable center conductor from end to end. Verify the resistance is less than 5 ohms.

• If the resistance is greater than 5 ohms, replace the antenna coaxial cable.

4. Test the resistance of the antenna coaxial cable outer shield from end to end. Verify the resistance is less than 5 ohms.

• If the resistance is greater than 5 ohms, replace the antenna coaxial cable.

5. Test the resistance of the antenna coaxial cable between the center conductor and the outer conductor. Verify there is infinite resistance between both conductors.

• If there is less than infinite resistance between the inner conductor and the outer conductor of the coaxial cable, replace the antenna coaxial cable. If the coaxial cable tests normal, replace the digital radio antenna.

Repair Instructions

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

Digital Radio Receiver Replacement (Digital Radio Receiver Replacement)