Digital Radio Poor or No Reception

Digital Radio Poor or No Reception

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.

Circuit/System Description

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

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
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 Control Module References for scan tool information
Special Tools

EL-48028 Digital Radio Test Antenna

Circuit/System Verification

1. Tune to a strong AM or FM station and verify each speaker is producing clear and even sound, with no distortion.

• If any speaker is not producing sound or the sound produced is distorted, refer to Speaker Malfunction Speaker Malfunction.

2. 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 digital radio antenna coax from the radio. Connect the EL-48028 to the radio and place on the roof of the vehicle. Move the vehicle outside in an area with an unobstructed view of the southern sky.
2. Ignition ON, radio tuned to XM channel 1, verify XM reception is clear and uninterrupted.

• If reception is not clear, replace the radio.

3. Ignition OFF, reconnect the antenna coax cable at the radio. Disconnect the antenna coax cable from the digital radio antenna.
4. Ignition ON, radio ON, test for 4.5-5.5 V between the antenna coax cable center terminal and outer shield.

• If less than the specified range, test the antenna coax cable for an open/high resistance.
• If greater than the specified range, test the antenna coax cable for a short to voltage.

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, Mobile Telephone, and Vehicle Location Base Replacement Digital Radio, Mobile Telephone, and Vehicle Location Base Replacement
* Control Module References Control Module References for radio replacement, setup, and programming