Radio Poor Reception

Radio Poor 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

AM and FM radio reception is dependent on the following components:

* Radio antenna - part of the rear glass
* Coax cable between the radio antenna and the radio antenna module
* Radio antenna module
* Coax cable between the radio antenna module and the radio
* Radio

Diagnostic Aids

Poor AM and FM radio reception is dependent on multiple influences, some of which may not be vehicle related. Areas which have high RF traffic or block the signal path may cause a degradation in radio reception. Radio reception may also be influenced by items within the vehicle, but not part of the radio system. Such examples are aftermarket electrical accessories or other items which may generated noise in the vehicle electrical system. Aftermarket window tinting, especially when there is a metallic in the film, may reduce radio reception.

AM reception is highly dependent on the antenna module receiving battery voltage from the radio. The antenna module has a built in antenna amplifier that boosts both AM and FM reception. When the antenna module no longer receives power, the radio will still receive FM stations and loose all AM stations.

Reference Information
Schematic Reference

Radio/Navigation System Schematics (Radio/Navigation System Schematics)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Radio Rear Speaker Replacement (Sedan, Coupe) (Radio Rear Speaker Replacement)
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

Circuit/System Testing

1. Ignition OFF, disconnect the coax from the antenna located at the rear glass.
2. Verify the coax connector at the back glass is properly secured and free of any damage.

• If damage is found, repair or replace as necessary.

3. Inspect the antenna on the rear glass. Verify all branches of the antenna are intact, with no scratches or other damage.

• If damage is found, repair or replace as necessary.

4. Inspect the radio antenna module grounding surfaces and the mounting hardware for any corrosion that may cause a poor ground.

• If corrosion is noted, clean the grounding surfaces or hardware.

5. Disconnect the harness connector at the antenna module.
6. Ignition ON, radio ON, verify a test lamp illuminates between the entertainment remote enable signal circuit terminal 1, and ground.

• If test lamp does not illuminate, test the circuit for short to ground or an open/high resistance. If circuit tests normal, replace the radio.

7. Disconnect the antenna coax from the radio and the radio antenna module.
8. Test for infinite resistance between the antenna coax center terminal and ground.

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

9. Test for less than 5 ohms of resistance on the antenna coax center terminal from end to end.

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

10. Test for less than 5 ohms of resistance on the antenna coax outer shield from end to end.

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

11. Test for infinite resistance between the coax center terminal and the outer shield.

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

12. If all circuits test normal, replace the antenna module.
13. Ignition ON, radio ON, verify radio reception has improved.

• If there is still poor reception, replace the radio.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Radio Antenna Module Replacement (Sedan) (Service and Repair)Radio Antenna Module Replacement (Wagon) (Service and Repair)Radio Antenna Module Replacement (Coupe) (Service and Repair)
* Control Module References (Programming and Relearning) for radio replacement, setup, and programming