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 02
- Antenna Ground Circuit Short to Ground

DTC B1259 05
- Antenna Ground Circuit Short to Battery or Open




Circuit/System Description

The antenna circuit is a coaxial cable that carries the digital radio signal information received by the antenna to the digital radio receiver (DRR). The antenna coax also provides a path for voltage to power the antenna.


Conditions for Running the DTC

Ignition is ON


Conditions for Setting the DTC

The DRR detects a short to voltage, short to ground, or an open in the antenna circuit


Action Taken When the DTC Sets

The radio displays No XM Signal


Conditions for Clearing the DTC

* A current DTC will clear when the conditions for setting the DTC are no longer present
* A history 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 (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Programming and Relearning (Programming and Relearning) for scan tool information
Special Tools

EL-48028 Digital Radio Test Antenna


Circuit System Verification

Ignition ON, radio tuned to XM, verify XM reception is clear and uninterrupted.


Circuit/System Testing

1. Ignition OFF, disconnect the antenna coax from the DRR. Connect the EL-48028 to the DRR.
2. Radio ON, tuned to XM, verify DTC B1259 is not set as current.

• If the DTC is current, replace the DRR.

3. Ignition OFF, disconnect the digital radio antenna coax from the digital radio antenna.
4. Ignition ON, test for less than 1 volt between the antenna coax center terminal and ground.

• If greater than the specified range, replace the antenna coax.

5. Test for infinite resistance between the antenna coax center terminal and ground.

• If less than the specified value, replace the antenna coax.

6. Test for less than 5 ohms of resistance on the antenna coax center circuit from end to end.

• If greater than the specified range, replace the antenna coax.

7. Test for infinite resistance between the coax center terminal and the outer shield.

• If less than the specified value, replace the antenna coax.

8. If all circuits test normal, test or replace the digital radio antenna.



Repair Instructions

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

* Digital Radio Antenna Cable Replacement (Service and Repair)
* Cellular Communications/Digital Radio Antenna Replacement (Cellular Communications/Digital Radio Antenna Replacement)
* Programming and Relearning (Programming and Relearning) for DRR replacement, setup, and programming