B125C

DTC B125C

Diagnostic Instructions

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

DTC Descriptors
DTC B125C 01
- Satellite Antenna 1 Circuit Short to Battery

DTC B125C 02
- Satellite Antenna 1 Circuit Short to Ground

DTC B125C 04
- Satellite Antenna 1 Circuit Open Circuit

Circuit/System Description

The digital radio receiver (DRR), located inside the radio, receives digital radio information from the digital radio antenna located on the outside of the vehicle. The DRR is connected to the digital radio antenna via a shielded coax cable.

Conditions for Running the DTC

This DTC is run every 300 milliseconds.

Conditions for Setting the DTC

The radio detects a circuit fault in the digital radio antenna.

Action Taken When the DTC Sets

The radio displays No XM Signal or Check Antenna.

Conditions for Clearing the DTC

* A current DTC clears when the condition for setting the DTC is no longer present.
* A history DTC clears after 100 malfunction-free ignition cycles.

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 (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

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. Verify XM reception is clear and the No XM Signal message is not displayed on the radio.

Circuit/System Testing

1. Ignition OFF, disconnect the DRR antenna coax from the radio. Connect the EL-48028 to the radio and place on the roof of the vehicle.
2. Ignition ON, radio tuned to XM channel 1. Verify XM reception is improved.

• If the reception is not improved, replace the radio.

3. Ignition OFF, disconnect the antenna coaxial from the digital radio antenna.
4. Ignition ON, test for 4.5-5.5 volts between the antenna coax center terminal and ground.

• If not within the specified range, replace the antenna coax.

5. Test for infinite resistance between the antenna coax center terminal and ground.

• If not the specified value, replace the antenna coax.

6. Test for less than 5 ohms end to end at the coax center conductor.

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

7. Test for less than 5 ohms end to end at the coax outer shield.

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

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

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

9. 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 and Mobile Telephone and Vehicle Location Base Replacement (Digital Radio and Mobile Telephone and Vehicle Location Base Replacement)
* Control Module References (Programming and Relearning)for radio replacement, setup, and programming