Symptom Troubleshooting
Audio System 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 Battery Test.
- Check the radio reception in an open area.
- Compare it to a known-good vehicle of the same model, year, and trim level whenever possible.
- If necessary, have the customer demonstrate the symptom.
- Poor reception/interference can be caused by any of these conditions:
- The radio station is far away.
- Atmospheric conditions are unfavorable.
- Tall buildings, mountains, or high-voltage power lines are nearby.
- Electronic accessories.
- Non-standard antenna mast.
- Check for aftermarket accessories plugged into the vehicle accessory power sockets (including cell phones).
- Check the connectors for poor connections or loose terminals.
1. Turn the ignition switch to ON (II).
2. Do the seek stop test.
Does the test vehicle receive 90 % of the same stations as the known-good vehicle?
YES -
Multipath interference or weak station. Operation is normal at this time.
NO -
Go to step 3.
3. Check if the radio reception/interference is the same as the known-good vehicle in several locations.
Is the reception/interference the same as the known-good vehicle in several different locations?
YES -
Multipath interference or weak station. Operation is normal.
NO -
Go to step 4.
4. Check the reception/interference while the engine is running, and compare it to the known-good vehicle.
Is there noise (static or whine) only with the engine running?
YES -
Check the antenna and radio grounds. If OK, check the charging system, the fuel injection system (fuel pump), the HVAC blower motor, and the ignition system.
NO -
Go to step 5.
5. Turn the ignition switch to LOCK (0).
6. Check the antenna mast for cracks or other damage. Make sure that the AM/FM antenna is not loose.
NOTE: Do not use any tools to tighten the antenna mast.
Is there any damage?
YES -
Replace the AM/FM antenna Service and Repair.
NO -
Go to step 7.
7. Disconnect the AM/FM antenna 3P connector.
8. Turn the ignition switch to ON (II).
9. Measure the voltage between AM/FM antenna 3P connector 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-navigation unit Audio-Navigation Unit Removal/Installation (With Navigation).
12. Disconnect audio-navigation unit connector G (3P).
13. Check for continuity between audio-navigation unit connector G (3P) terminal No. 3 and AM/FM antenna 3P connector terminal No. 3.
Is there continuity?
YES -
Go to step 14.
NO -
There is an open in the wire between the audio-navigation unit and the AM/FM antenna.
14. Check for continuity between AM/FM antenna 3P connector terminal No. 3 and body ground.
Is there continuity?
YES -
Repair a short in the wire between the audio-navigation unit and the AM/FM antenna.
NO -
Substitute a known-good audio-navigation unit, and recheck.
15. Remove the audio-navigation unit Audio-Navigation Unit Removal/Installation (With Navigation).
16. Check for continuity between audio-navigation unit connector G (3P) terminal No. 1 and AM/FM antenna 3P connector terminal No. 1.
Is there continuity?
YES -
Go to step 17.
NO -
Replace the antenna lead and/or the sublead.
17. Check for continuity between audio-navigation unit connector G (3P) terminal No. 1 and body ground.
Is there continuity?
YES -
Replace the antenna lead and/or the sublead.
NO -
Go to step 18.
18. Check for continuity between audio-navigation unit connector G (3P) terminal No. 2 and AM/FM antenna 3P connector terminal No. 2.
Is there continuity?
YES -
Go to step 19.
NO -
Replace the antenna lead and/or the sublead.
19. Check for continuity between audio-navigation unit connector G (3P) terminals No. 1 and No. 2.
Is there continuity?
YES -
Replace the antenna lead and/or the sublead.
NO -
Replace the AM/FM antenna Service and Repair, and recheck. If the reception is still poor, replace the audio-navigation unit Audio-Navigation Unit Removal/Installation (With Navigation).