Poor AM or FM Radio Reception or Interference (With Navigation)
Poor AM or FM radio reception or interference (with navigation)NOTE:
- Check the vehicle battery condition first.
- 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. 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 tint.
1. Turn the ignition switch to 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. 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. Wrap aluminum foil (A) around the tip of a tester probe (B) as shown.
8. Check for continuity by touching one tester probe to the window antenna terminal (A), and move the other tester probe along the antenna wires.
Is there continuity in all sections of the antenna?
YES - Go to step 9.
NO - Repair the window antenna wire. Go to AM/FM Antenna Repair. AM/FM Antenna Repair
9. Remove the navigation unit. Check that the antenna lead is properly connected.
Is it connected properly?
YES - Go to step 10.
NO - Reconnect the connector, and recheck the function.
10. Disconnect the AM/FM antenna lead 3P connector from the AM/FM antenna amplifier.
11. Turn the ignition switch to ON (II).
12. Turn on the navigation unit.
13. Measure the voltage between the AM/FM antenna lead connector No. 3 terminal at the AM/FM antenna amplifier and body ground.
Is there battery voltage?
YES - Go to step 18.
NO - Go to step 14.
14. Turn the ignition switch to LOCK (0).
15. Disconnect navigation unit connector G (3P).
16. Check for continuity between the AM/FM antenna amplifier connector (3P) No. 3 terminal and body ground.
Is there continuity?
YES - Repair short to body ground in the wire between the navigation unit and the AM/FM antenna amplifier.
NO - Go to step 17.
17. Check for continuity between navigation unit connector G (3P) No. 3 terminal and the AM/FM antenna amplifier 3P connector No. 3 terminal.
Is there continuity?
YES - Substitute a known-good navigation unit, and recheck.
NO - Repair open in the wire between the navigation unit and the AM/FM antenna amplifier.
18. Turn the ignition switch to LOCK (0).
19. Disconnect navigation unit connector G (3P).
20. Check for continuity between navigation unit connector G (3P) No. 1 terminal and body ground.
Is there continuity?
YES - Replace the AM/FM antenna lead and/or sublead.
NO - Go to step 21.
21. Check for continuity between navigation unit connector G (3P) No. 1 and No. 2 terminals.
Is there continuity?
YES - Replace the antenna lead and/or sublead.
NO - Go to step 22.
22. Check for continuity between navigation unit connector G (3P) No. 2 terminal and the AM/FM antenna amplifier 3P connector No. 2 terminal.
Is there continuity?
YES - Replace the antenna lead and/or sublead.
NO - Go to step 23.
23. Check for continuity between navigation unit connector G (3P) No. 1 terminal and the AM/FM antenna amplifier 3P connector No. 1 terminal.
Is there continuity?
YES - Replace the AM/FM antenna amplifier, and recheck. If the reception is still poor, replace the navigation unit.
NO - Replace the AM/FM antenna lead and/or sublead.