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. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Left Audio Signal (+) | 1 | 1 | 1 | -- |
Right Audio Signal (+) | 2 | 2 | 2 | -- |
Audio Common Signal (-) | 3 | 3 | 3 | -- |
Digital Radio Antenna Coax | B1259* | B1259* | B1259* | -- |
1. No or distorted audio from left side speakers when listening to digital radio 2. No or distorted audio from right side speakers when listening to digital radio 3. No or distorted audio from all speakers when listening to digital radio * Poor or no digital radio reception. | ||||
Circuit/System Description
The digital radio receiver (DRR) receives an XM satellite radio signal via the cellular and digital radio antenna. This signal is passed to the DRR through the digital radio antenna coax. From the DRR, two left and right audio signals (+) and one audio common (-) are sent to the radio. The radio then processes these signals and passes the audio to the appropriate speakers or amplifier.
Reference Information
Schematic Reference
Radio/Navigation System Schematics
Connector End View Reference
Description and Operation
Radio/Audio System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Special Tools
EL-48028 Digital Radio Test Antenna
Circuit/System Verification
- Tune to a strong AM or FM station and verify each speaker is producing clear and even sound, with no distortion.
- 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.
- Radio tuned to XM, use the radio balance function to transfer audio between the left and right side of the vehicle. Verify clear and even sound is heard from each side of the vehicle.
| ⇒ | If any speaker is not producing sound or the sound produced is distorted, refer to Speaker Malfunction. |
| ⇒ | If the No XM Signal message is displayed or XM reception is poor, refer to Digital Radio Antenna Circuit Malfunction. |
| ⇒ | If either side of the vehicle is not producing sound or the sound produced is distorted, refer to Digital Radio Signal Circuit Malfunction. |
Circuit/System Testing
Digital Radio Antenna Circuit Malfunction
- Ignition OFF, disconnect the digital radio antenna coax from the digital radio receiver (DRR). Connect the EL-48028 to the DRR.
- Ignition ON, radio tuned to XM, verify XM reception is clear and uninterrupted.
- Ignition OFF, reconnect the antenna coax to the DRR, disconnect the digital radio antenna coax from the digital radio antenna.
- Ignition ON, test for 4.5-5.5 volts between the antenna coax center terminal and the coax outer shield.
- If all circuits test normal, replace the digital radio antenna.
| ⇒ | If reception is not clear, replace the DRR. |
| ⇒ | If not within the specified range, replace the antenna coax. |
Digital Radio Signal Circuit Malfunction
- Ignition OFF, disconnect the X2 harness connector at the radio.
- Ignition ON, radio ON and tuned to XM, test for a varying mV AC voltage reading between the following signal circuit terminals listed below and ground.
- If all circuits test normal, replace the radio.
| • | Left audio signal (+) - terminal 1 |
| • | Right audio signal (+) - terminal 2 |
| • | Audio common signal (-) - terminal 9 |
| ⇒ | If the varrying mV A/C voltage is not present, test the signal circuit for a short to voltage, short to ground, or an open/high resistance. If the circuit tests normal, replace the DRR. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for Radio and DRR replacement, setup, and programming |
