Poor AM/FM Radio Reception or Interference
Poor AM or FM radio reception or interferenceNOTE:
- Check the vehicle battery condition first.
- 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 window tint.
1. Turn the ignition switch ON (II).
2. Do the seek stop test.
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 antenna and radio grounds. If OK, check the charging system and the ignition system.
NO - Go to step 5.
5. Turn the ignition switch OFF.
6. Do the AM/FM antenna test.
Is there continuity in all sections of the antenna?
YES - Go to step 7.
NO - Repair the window antenna wire. Go to AM/FM Antenna Repair. Procedures
7. Remove the audio unit. Check that AM/FM antenna sublead is properly connected.
NOTE: Eject all the discs before removing the audio unit to prevent damaging the CD player's load mechanism.
Is it connected properly?
YES - Go to step 8.
NO - Reconnect the connector, and recheck the function.
8. Disconnect the AM/FM antenna amplifier 3P connector.
9. Turn the ignition switch ON (II).
10. Turn on the audio unit and select AM or FM.
11. Measure the voltage between the AM/FM antenna amplifier 3P connector No.3 terminal and body ground.
Is there battery voltage?
YES - Go to step 16.
NO - Go to step 12.
12. Turn the ignition switch OFF.
13. Disconnect the audio unit connector E (3P).
14. Check for continuity between the audio unit connector E (3P) terminal No.3 and the AM/FM antenna amplifier 3P connector terminal No.3.
Is there continuity?
YES - Go to step 15.
NO - Repair open in the wire between the audio unit and the AM/FM antenna amplifier and check the AM/FM antenna lead and sublead connections.
15. Check for continuity between body ground and audio unit connector E (3P) terminal No.3.
Is there continuity?
YES - Repair short to body ground in the wire.
NO - Replace the audio unit.
16. Turn the ignition switch OFF.
17. Disconnect the audio unit connector E (3P).
18. Check for continuity between the audio unit connector E (3P) terminal No.1 and the AM/FM antenna amplifier 3P connector terminal No.1.
Is there continuity?
YES - Go to step 19.
NO - Replace the AM/FM antenna lead and/or sublead.
19. Check for continuity between the audio unit connector E (3P) terminal No.1 and body ground.
Is there continuity?
YES - Replace the AM/FM antenna lead and/or sublead.
NO - Go to step 20.
20. Check for continuity between the audio unit connector E (3P) connector terminal No.2 and the AM/FM antenna amplifier 3P connector terminal No.2.
Is there continuity?
YES - Go to step 21.
NO - Replace the AM/FM antenna lead and/or sublead.
21. Check for continuity between the audio unit connector E (3P) terminal No.1 and No.2.
Is there continuity?
YES - Replace the AM/FM antenna lead and/or sublead.
NO - Replace the AM/FM antenna amplifier, and recheck. If the reception is still poor, replace the audio unit.