B1259

DTC B1259

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B1259 00
- Antenna Ground Circuit Malfunction

Diagnostic Fault Information






Circuit/System Description

The digital radio receiver (DRR) receives XM satellite radio signals via a digital radio antenna located on the outside of the vehicle. The signal is passed to the DRR through digital radio antenna coax. From the DRR, separate left and right audio signals (+) are sent to the radio. The radio processes these signals and passes the audio to the appropriate speakers or audio amplifier.

Conditions for Running the DTC

* The radio is ON.
* Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

The DTC will set when the DRR detects a short to voltage, short to ground, or an open/high resistance in the antenna ground 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.

Special Tools

EL-48028 Digital Radio Test Antenna

Circuit/System Testing

Important:
* Ensure the vehicle is outside in an area with an unobstructed view of the southern sky. Turn XM radio ON. Tune the radio to satellite channel 1. XM reception should be clear.

* Contact XM radio services at 1-800-852-9696 to verify the customers account status or possible network problems.

1. Ignition OFF, disconnect the digital radio antenna coax from the digital radio receiver (DRR). Connect the EL-48028 to the DRR.
2. Ignition ON, radio tuned to XM, verify XM reception is clear and uninterrupted.

• If reception is not clear, 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 on the antenna coax center circuit from end to end.

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

7. Test for less than 5 ohms between the two ends of the coax cable outer shield.

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

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

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

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

Repair Instructions

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

* Digital Radio Antenna Replacement
* Digital Radio Antenna Cable Replacement