Symptom Troubleshooting
Symptom Troubleshooting: Poor AM or FM radio reception or interference
Poor AM or FM radio reception or interference (with navigation)
NOTE:
- Check the vehicle battery condition first.
- Check for aftermarket accessories including cell phones and chargers plugged into the vehicle accessory power sockets.
- Check the connectors for poor connections or loose terminals.
- Check the radio reception in an open area. Compare it to a known-good vehicle whenever possible. 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 tinting or electronic accessories.
1. Turn the ignition switch to ON (II).
2. Do the seek stop test. Sound Quality Diagnosis - 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. Start the engine.
5. Check the reception/interference.
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 6.
6. Turn the ignition switch to LOCK (0).
7. Check the AM/FM/XM antenna or AM/FM antenna mast for cracks or other damage. Verify that the AM/FM/XM antenna or AM/FM antenna mast is not loose.
NOTE: Do not use any tools to tighten the AM/FM/XM antenna or AM/FM antenna mast.
Is there any damage?
YES - Replace the AM/FM/XM antenna mast, AM/FM/XM Antenna Replacement (With Navigation) or AM/FM antenna mast. AM/FM Antenna Replacement (Without Navigation)
NO - Go to step 8.
8. Disconnect the AM/FM antenna lead 3P connector from the AM/FM/XM antenna or AM/FM antenna.
9. Turn the ignition switch to ON (II) and turn ON the navigation unit.
10. Measure the voltage between the AM/FM/XM antenna or AM/FM antenna 3P connector terminal No. 3 and body ground.
Is there battery voltage?
YES - Go to step 11.
NO - Go to step 17.
11. Turn the ignition switch to LOCK (0).
12. Remove the navigation unit. Service and Repair
13. Check for continuity between navigation unit connector G (3P) terminal No. 1 and the AM/FM/XM antenna or AM/FM antenna 3P connector terminal No. 1.
Is there continuity?
YES - Go to step 14.
NO - Replace the AM/FM antenna lead and/or sublead.
14. Check for continuity between navigation unit connector G (3P) terminal No. 1 and body ground.
Is there continuity?
YES - Replace the AM/FM antenna lead and/or sublead.
NO - Go to step 15.
15. Check for continuity between navigation unit connector G (3P) terminal No. 2 and the AM/FM/XM antenna or AM/FM antenna 3P connector terminal No. 2.
Is there continuity?
YES - Replace the AM/FM antenna lead and/or sublead.
NO - Go to step 16.
16. Check for continuity between navigation unit connector G (3P) terminals No. 1 and No. 2.
Is there continuity?
YES - Replace the AM/FM antenna lead and/or sublead.
NO - Replace the AM/FM/XM antenna or AM/FM antenna, and recheck. If the reception is still poor, replace the navigation unit. Service and Repair
17. Turn the ignition switch to LOCK (0).
18. Remove the navigation unit. Service and Repair
19. Check for continuity between navigation unit connector G (3P) terminal No. 3 and the AM/FM/XM antenna or AM/FM antenna 3P connector terminal No. 3.
Is there continuity?
YES - Go to step 20.
NO - Repair open in the wire between the navigation unit and the AM/FM/XM antenna or AM/FM antenna.
20. Check for continuity between the AM/FM/XM antenna connector (3P) or AM/FM antenna connector (3P) terminal No. 3 and body ground.
Is there continuity?
YES - Repair short in the wire between the navigation unit and the AM/FM/XM antenna or AM/FM antenna.
NO - Substitute a known-good navigation unit, Service and Repair and recheck.
