The antenna signal circuit is a coaxial cable that carries the radio signal information received by the antenna to the digital radio receiver (DRR).

This test is run every 300 milliseconds

The DRR detects an antenna fault.

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

Schematic Reference

156621 Radio/Audio System Schematics

Connector End View Reference

156619 Entertainment Connector End Views

Description and Operation

Radio/Audio System Description and OperationRadio/Audio System Description and Operation

Electrical Information Reference

Special Tools Required

EL-48028 EL-48028 Digital Radio Test Antenna

1. Ignition OFF, disconnect the antenna coax from the digital radio receiver. 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.

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