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 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

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 after completing the diagnostic procedure. Verification Tests

* Digital Radio Antenna Cable Replacement
* Cellular Communications/Digital Radio Antenna Replacement