Symptom Troubleshooting
Audio System Symptom Troubleshooting - Poor AM or FM radio reception or interference
Poor AM or FM radio reception or interference
NOTE:
- Check the vehicle battery condition first Testing and Inspection.
- Check for aftermarket accessories plugged into the vehicle accessory power sockets.
- Check the connectors for poor connections or loose terminals.
- Check the radio reception in an open area. Poor reception/interference can be caused by the following:
- The radio station is far away.
- Atmospheric conditions are unfavorable.
- Tall buildings, mountains, or high-voltage power lines are nearby.
- Aftermarket metallic window tint.
1. Turn the ignition switch to ON (II).
2. Do the seek stop test Audio System Sound Quality Diagnosis.
Is the test vehicle within 10 % of the known-good vehicle?
YES -
Multipath interference or weak station. Operation is normal.�
NO -
Go to step 3.
3. Check if the radio reception/interference is the same in several locations.
Is the reception/interference the same?
YES -
Go to step 4.
NO -
Multipath interference or weak station. Operation is normal.�
4. Check the reception/interference while the engine is running.
Is there noise (static or whine) only with the engine running?
YES -
Check the AM/FM antenna amplifier and radio grounds. If OK, check the charging system and the ignition system.�
NO -
Go to step 5.
5. Turn the ignition switch to LOCK (0).
6. Check the connections from the AM/FM antenna amplifier to the window antenna.
Are there any loose or damaged connections?
YES -
Repair the connections, or substitute a known-good AM/FM antenna amplifier Service and Repair, and retest. If the symptom/condition goes away, replace the original AM/FM antenna amplifier.�
NO -
Go to step 7.
7. With the help of an assistant inside the vehicle, have the assistant shine a strong flashlight (A) along each antenna wire (B). Check from the outside of the vehicle for any breaks or openings in the antenna wires (the light shines through any breaks or cuts).
NOTE: It is easier to see the breaks if you do this test in a dark or shaded area.
Are there any breaks or cuts in the antenna?
YES -
Repair the window antenna. Go to AM/FM antenna repair Procedures, or replace the right quarter glass if the damaged section is too long.�
NO -
Go to step 8.
8. Remove the dashboard center lower Dashboard Center Panel Removal/Installation. Check that the AM/FM antenna sublead connector is properly connected.
Is the AM/FM antenna sublead connected properly?
YES -
Go to step 9.
NO -
Reconnect the antenna sublead connector, and recheck the function.
9. Disconnect the AM/FM antenna amplifier 3P connector Service and Repair.
10. Turn the ignition switch to ON (II).
11. Turn on the audio unit.
12. Measure the voltage between AM/FM antenna amplifier 3P connector terminal No. 3 and body ground.
Is there battery voltage?
YES -
Go to step 16.
NO -
Go to step 13.
13. Turn the ignition switch to LOCK (0).
14. Remove the audio unit Audio Unit Removal/Installation, and disconnect audio unit connector G (3P).
15. Check for continuity between audio unit connector G (3P) terminal No. 3 and AM/FM antenna amplifier 3P connector terminal No. 3.
Is there continuity?
YES -
Replace the audio unit Audio Unit Removal/Installation.�
NO -
Repair an open in the wire between the audio unit and the AM/FM antenna amplifier.�
16. Turn the ignition switch to LOCK (0).
17. Check for continuity between audio unit connector G (3P) terminal No. 1 and AM/FM antenna amplifier 3P connector terminal No. 1.
Is there continuity?
YES -
Go to step 18.
NO -
Replace the antenna lead and/or sublead.�
18. Check for continuity between audio unit connector G (3P) terminal No. 1 and body ground.
Is there continuity?
YES -
Replace the antenna lead and/or sublead.�
NO -
Go to step 19.
19. Check for continuity between audio unit connector G (3P) terminal No. 2 and AM/FM antenna amplifier 3P connector terminal No. 2.
Is there continuity?
YES -
Go to step 20.
NO -
Replace the antenna lead and/or sublead.�
20. Check for continuity between audio unit connector G (3P) terminals No. 1 and No. 2.
Is there continuity?
YES -
Replace the antenna lead and/or sublead.�
NO -
Replace the AM/FM antenna amplifier Service and Repair, and recheck. If the reception is still poor, replace the audio unit Audio Unit Removal/Installation.�