Poor AM or FM Radio Reception or Interference (With XM)
Poor AM or FM radio reception or interference (with XM)NOTE:
- 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.
- A tall building, a mountain, or a high-voltage power line is 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 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. Check the AM/FM/XM antenna mast for cracks, or other damage. Make sure that the AM/FM/XM antenna mast isn't loose.
NOTE: Do not use any tools to tighten the AM/FM/XM antenna mast.
Is there any damage?
YES - Replace the AM/FM/XM antenna mast.
NO - Go to step 7.
7. Disconnect the AM/FM/XM antenna 3P connector from the AM/FM/XM antenna.
8. Turn the ignition switch ON (II).
9. Turn on the audio unit and select AM or FM.
10. Measure the voltage between AM/FM/XM antenna 3P connector No.3 terminal and body ground.
Is there battery voltage?
YES - Go to step 15.
NO - Go to step 11.
11. Turn the ignition switch OFF.
12. Remove the audio unit, and disconnect audio unit connector E (3P)
NOTE: Eject all the CDs before remove the audio unit to prevent damaging the CD player's load mechanism.
13. Check for continuity between audio unit connector E (3P) No.3 terminal and the AM/FM/XM antenna 3P connector No.3 terminal.
Is there continuity?
YES - Go to step 14.
NO - Repair open in the wire between the audio unit and the AM/FM/XM antenna. Also check the AM/FM antenna lead/sublead connector.
14. Check for continuity between the audio unit connector E (3P) terminal No.3 and body ground.
Is there continuity?
YES - Repair short to body ground in the wire between the audio unit and AM/FM/XM antenna.
NO - Replace the audio unit.
15. Turn the ignition switch OFF.
16. Remove the audio unit, and disconnect audio unit connector E (3P).
NOTE: Eject all the CDs before remove the audio unit to prevent damaging the CD player's load mechanism.
17. Check for continuity between audio unit connector E (3P) No.1 terminal and the AM/FM/XM antenna 3P connector No.1 terminal.
Is there continuity?
YES - Go to step 18.
NO - Replace the AM/FM antenna lead and/or sublead.
18. 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 19.
19. Check for continuity between the audio unit connector E (3P) terminal No.2 and the AM/FM/XM antenna 3P connector No.2 terminal.
Is there continuity?
YES - Go to step 20.
NO - Replace the AM/FM antenna lead and/or sublead.
20. 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 - Go to step 21.
21. Substitute a known-good AM/FM antenna lead and/or sublead, and check the radio reception.
Is the reception normal?
YES - Replace the AM/FM antenna lead and/or sublead.
NO - Substitute a known-good AM/FM/XM antenna and recheck. If the reception is still poor, replace the audio unit.