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 the connectors for poor for connections or loose terminals.
- Check the radio reception in an open area. Poor reception/interference can be caused by any of these conditions:
- The radio station is far away.
- Atmospheric conditions are unfavorable.
- Aftermarket metallic window tinting can affect reception on vehicles with window antennas. If the vehicle has aftermarket metallic window tinting, advise your client that it would have to be removed for proper testing.
- A tall building, mountains, or high-voltage power lines are nearby.
1. Turn the ignition switch to ON (II).
2. Do the seek stop test and reception level indication in the Self-diagnostic Function.
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 that the 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 antenna and radio grounds. If OK, check the charging system and the ignition system.�
NO -
Go to step 5.
5. Do the seek stop test and reception level indication in the Self-diagnostic Function.
Is the test vehicle within 10 % of the known-good vehicle?
YES -
Multipath interference or weak station.�
NO -
Go to step 6.
6. Check the AM/FM/XM antenna mast for cracks, or other damage. Verify that the AM/FM/XM antenna mast is tight.
NOTE: Do not use any tools to tighten the AM/FM antenna mast.
Is there any damage?
YES -
Replace the AM/FM/XM antenna mast AM/FM/XM Antenna Replacement.�
NO -
Go to step 7.
7. Disconnect AM/FM/XM antenna connector A (3P).
8. Turn the ignition switch to ON (II).
9. Measure the voltage between AM/FM/XM antenna connector A (3P) terminal No. 3 and body ground.
Is there battery voltage?
YES -
Go to step 15.
NO -
Go to step 10.
10. Turn the ignition switch to LOCK (0).
11. Remove the audio unit.
- With ELS audio system Audio Unit Removal/Installation (With Navigation System)
- With premium audio system Audio Unit Removal/Installation (Without Navigation System)
12. Disconnect audio unit connector E (3P).
13. Check for continuity between audio unit connector E (3P) terminal No. 3 and AM/FM/XM antenna connector A (3P) terminal No. 3.
Is there continuity?
YES -
Go to step 14.
NO -
Repair an open in the wire between the audio unit and the AM/FM/XM antenna. Also check the AM/FM/XM antenna lead/sublead connector.�
14. Check for continuity between audio unit connector E (3P) terminal No. 3 and body ground.
Is there continuity?
YES -
Repair a short to body ground in the wire between the audio unit and the AM/FM/XM antenna.�
NO -
- With ELS audio system: Substitute a known-good audio unit Audio Unit Removal/Installation (With Navigation System), and recheck. If the symptom/indication goes away, replace the original audio unit Audio Unit Removal/Installation (With Navigation System).�
- With premium audio system: Substitute a known-good audio unit Audio Unit Removal/Installation (Without Navigation System), and recheck. If the symptom/indication goes away, replace the original audio unit Audio Unit Removal/Installation (Without Navigation System).�
15. Remove the audio unit:
- With ELS audio system Audio Unit Removal/Installation (With Navigation System)
- With premium audio system Audio Unit Removal/Installation (Without Navigation System)
16. Disconnect audio unit connector E (3P).
17. Check for continuity between audio unit connector E (3P) terminal No. 1 and AM/FM/XM antenna connector A (3P) terminal No. 1.
Is there continuity?
YES -
Go to step 18.
NO -
Replace the AM/FM/XM antenna lead and/or sublead.�
18. Check for continuity between audio unit connector E (3P) terminal No. 1 and body ground.
Is there continuity?
YES -
Replace the AM/FM/XM antenna lead and/or sublead.�
NO -
Go to step 19.
19. Check for continuity between audio unit connector E (3P) terminal No. 2 and AM/FM/XM antenna connector A (3P) terminal No. 2.
Is there continuity?
YES -
Go to step 20.
NO -
Replace the AM/FM/XM antenna lead and/or sublead.�
20. Check for continuity between audio unit connector E (3P) terminal No. 1 and No. 2.
Is there continuity?
YES -
Replace the AM/FM/XM antenna lead and/or sublead.�
NO -
Replace the AM/FM/XM antenna AM/FM/XM Antenna Replacement and recheck. If the reception is still poor, substitute a known-good audio unit with ELS audio system Audio Unit Removal/Installation (With Navigation System), with premium audio system Audio Unit Removal/Installation (Without Navigation System), and recheck. If the symptom/indication goes away, replace the original audio unit with ELS audio system Audio Unit Removal/Installation (With Navigation System), with premium audio system Audio Unit Removal/Installation (Without Navigation System).�