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 Descriptor
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 digital radio receiver (DRR) receives an XM(TM) satellite radio signal via the digital radio antenna. This signal is passed to the DRR through the digital radio antenna coax. The DRR sends a varying AC mV signal through separate left and right audio circuits (+ and -) to the radio. The voltage amount and rate of change is dependent upon the type of signal being received. The radio then processes these signals and passes the audio to the appropriate speakers or amplifier.
Conditions for Running the DTC
* The radio is 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 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.
Diagnostic Aids
When diagnosing digital radio concerns, the vehicle should be located outside with an unobstructed view of the southern sky to ensure proper reception of the satellite signal. Reception may be limited, intermittent, or not possible inside structures or under heavy cover.
Reference Information
Schematic Reference
Radio/Navigation System Schematics (Radio/Navigation System Schematics)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Radio/Audio System Description and Operation (Radio/Audio System Description and Operation)
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(TM). Verify XM(TM) reception is clear and the No XM(TM) 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. Radio ON, tuned to XM(TM), verify DTC B1259 is not set.
• If the DTC is set, 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 Replacement (Digital Radio Antenna Replacement)
* Digital Radio Antenna Cable Replacement (Digital Radio Antenna Cable Replacement)
* Control Module References (Programming and Relearning) for DRR replacement, setup, and programming