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. 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.

Schematic Reference

Radio/Navigation System Schematics

Connector End View Reference

Entertainment/Communication Connector End Views

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

1. Inspect the antenna for proper mounting or physical damage.

⇒	If damage is found, repair or replace as necessary

2. Radio ON, tune to several known FM, AM, and XM (if equipped) stations, and play a known good CD.

⇒	If audio output is poor from all sources, refer to Speakers Inoperative - One or More.

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 battery positive voltage circuit terminal 1, and ground.

⇒	If test lamp does not illuminate, test the circuit for short to ground or an open/high resistance.

7. Ignition ON, radio ON and tuned to FM, test for 5-8 volts between the FM composite signal terminal 2 abd ground.

⇒	If less than the specified range, test the circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the radio.

⇒	If greater than specified range, test the circuit for a short to voltage. If the circuit tests normal, replace the radio.

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

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

10. 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.

11. 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.

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

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

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

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.