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 Descriptors
DTC B1259 02
- Antenna Ground Circuit Short to Ground

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

Diagnostic Fault Information






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

* Radio ON.
* Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

B1259 02

The DRR detects a short to ground in the antenna circuit.

B1259 05

The DRR detects a short to voltage or an open/high resistance in the antenna circuit.

Actions Taken When the DTC Sets

* Digital radio reception may be poor or not available.
* The radio displays "No XM Signal" or "Check Antenna".

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

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

Component Connector End Views Connector End Views By Name
Description and Operation

Radio/Audio System Description and Operation Radio/Audio System
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

Scan Tool Reference

Control Module References Programming and Relearning for scan tool information
Special Tools

EL-48028 Digital Radio Test Antenna

Circuit System Verification

With the vehicle outside in an area with an unobstructed view of the southern sky, tune to XM. Verify XM reception is clear and the No XM Signal message is not displayed on the radio.

Circuit/System Testing

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

• If the DTC is current, replace the DRR.

3. Ignition OFF, reconnect the antenna coax to the DRR, disconnect the digital radio antenna coax from the digital radio antenna.
4. Ignition ON, test for 4.5-5.5 volts between the antenna coax center terminal and the coax outer shield.

• If not within the specified range, replace the antenna coax.

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

Repair Instructions

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

* Digital Radio Antenna Cable Replacement Digital Radio Antenna Cable Replacement
* Cellular Communications/Digital Radio Antenna Replacement Cellular Communications/Digital Radio Antenna Replacement
* Control Module References Programming and Relearning for DRR replacement, setup, and programming