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

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.

Diagnosing a poor reception concern will require a systematic approach to isolating the cause. Individual components should each be tested before proceeding with any repair or replacement.

Using a Test Antenna

Use a test mast antenna to check for poor vehicle antenna operation. Disconnect the antenna coax from the radio and plug the test antenna into radio. Make sure the test antenna base is grounded to the vehicle chassis and keep hands off the mast. Check radio reception in an area away from electrical interferences. Tune to several weak and strong AM and FM stations. If the radio reception improved, the problem exists with the vehicle antenna and/or lead-in cable. If the reception is still poor, refer to Speaker Malfunction.

Schematic Reference

Radio/Navigation System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Radio Rear Speaker Replacement

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Antenna Coaxial Cable Testing

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

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

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

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

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

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

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

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

Rear Glass Antenna Inspection

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.

Radio Antenna Module Test

1. 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.

2. Ignition OFF, disconnect the harness connector at the radio antenna module.
3. Radio ON, verify a test lamp illuminates between the signal circuit terminal 1 and ground.

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

4. If all circuits test normal, replace the radio antenna module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.