For 1990-2009 cars only
Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | 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: Antenna Ground CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Antenna Signal | 1 | 1 | 1 | -- |
1. Sets code B1259 | ||||
Circuit/System Description
The antenna signal circuit is a coaxial cable that carries the radio signal information received by the antenna. The antenna cable also provides a path for DC current for powering the antenna.
Conditions for Running the DTC
This test is run every 300 milliseconds.
Conditions for Setting the DTC
The digital radio receiver (DRR) detects an antenna fault.
Action Taken When the DTC Sets
The radio displays "No XM Signal" or "Check Antenna".
Conditions for Clearing the DTC
| • | The condition must be corrected. |
| • | The DTC clears after 100 malfunction-free ignition cycles. |
Reference Information
Schematic Reference
Radio/Navigation System Schematics
Connector End View Reference
Entertainment/Communication Connector End Views
Description and Operation
Radio/Audio System Description and Operation
Electrical Information Reference
Special Tools Required
EL-48028 Digital Radio Test Antenna
Circuit/System Testing
- Ignition OFF, disconnect the digital radio receiver antenna coax .Connect the test antenna to the DRR.
- Turn the ignition ON, radio ON tuned to XM. Verify that DTC B1259 is not current.
- 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.
- Test the resistance of the antenna coaxial cable outer shield from end to end. Verify the resistance is less than 5 ohms.
- 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 the DTC B1259 is still current, replace the DRR. |
| ⇒ | If the resistance is greater than 5 ohms, replace the antenna coaxial cable. |
| ⇒ | If the resistance is greater than 5 ohms , replace the antenna coaxial cable. |
| ⇒ | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
