Audio System Symptom Troubleshooting - Poor AM or FM radio reception or interference(With Normal Audio)
NOTE:
- Check the vehicle 12 volt battery condition first .
- Check for aftermarket accessories plugged into the vehicle accessory power sockets.
- Check for any radio frequency modulators that are plugged into the FM antenna lead. These modulators allow customers to play audio from accessories like CD players or game consoles using the audio system, but they can create interference issues.
- 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
- Electrical loads like the rear window defroster, seat heaters, game consoles, etc.
- Check the connectors for poor connections or loose terminals.
- 1. Problem verification:
- 1. Turn the vehicle to the ON mode.
- 2. Do the Seek Stop Test in the Sound Quality Diagnosis - Refer to: Audio System Sound Quality DiagnosisAudio System Diagnostic Mode .
Is the test vehicle within 10 % of the known-good vehicle?
YES
Multipath interference or weak station. Operation is normal.
NO
The failure is duplicated, go to step 2.
- 2. Determine possible failure area (charging system and ignition system, others):
- 1. Start the engine, and turn on the electrical loads one at a time (defrosters, seat heaters, blower motor, etc.).
- 2. 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 3.
- 3. Determine possible failure area (SWD +B line, AM/FM line):
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connector.
Roof antenna connector A (3P) - 3. Turn the vehicle to the ON mode
- 4. Turn on the audio system.
- 5. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode Roof antenna connector A (3P): disconnected Test point 1 Roof antenna connector A (3P) No. 1 Test point 2 Body ground Is there battery voltage?
YES
The SWD +B wire is OK. Go to step 4.
NO
Go to step 9.
- 4. Open wire check (AM/FM line):
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connector.
Audio unit connector D (3P) - 3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Roof antenna connector A (3P): disconnected Audio unit connector D (3P): disconnected Test point 1 Audio unit connector D (3P) No. 2 - Refer to: Audio Unit Connector for Inputs and Outputs(With Display Audio)Audio Unit Connector for Inputs and Outputs(With Normal Audio) Test point 2 Roof antenna connector A (3P) No. 2 Is there continuity?
YES
The AM/FM wire is not open. Go to step 5.
NO
Replace the AM/FM antenna lead and/or the sublead.
- 5. Shorted wire check (AM/FM line):
- 1. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Roof antenna connector A (3P): disconnected Audio unit connector D (3P): disconnected Test point 1 Audio unit connector D (3P) No. 2 - Refer to: Audio Unit Connector for Inputs and Outputs(With Display Audio)Audio Unit Connector for Inputs and Outputs(With Normal Audio) Test point 2 Body ground Is there continuity?
YES
Replace the AM/FM antenna lead and/or the sublead.
NO
The AM/FM wire is not shorted to ground. Go to step 6.
- 6. Open wire check (SH (AM/FM) line):
- 1. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Roof antenna connector A (3P): disconnected Audio unit connector D (3P): disconnected Test point 1 Audio unit connector D (3P) No. 3 - Refer to: Audio Unit Connector for Inputs and Outputs(With Display Audio)Audio Unit Connector for Inputs and Outputs(With Normal Audio) Test point 2 Roof antenna connector A (3P) No. 3 Is there continuity?
YES
The SH (AM/FM) wire is not open. Go to step 7.
NO
Replace the AM/FM antenna lead and/or the sublead.
- 7. Shorted wire check (AM/FM line to SH (AM/FM) line):
- 1. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Roof antenna connector A (3P): disconnected Audio unit connector D (3P): disconnected Test point 1 Audio unit connector D (3P) No. 2 - Refer to: Audio Unit Connector for Inputs and Outputs(With Display Audio)Audio Unit Connector for Inputs and Outputs(With Normal Audio) Test point 2 Audio unit connector D (3P) No. 3 - Refer to: Audio Unit Connector for Inputs and Outputs(With Display Audio)Audio Unit Connector for Inputs and Outputs(With Normal Audio) Is there continuity?
YES
Replace the AM/FM antenna lead and/or the sublead.
NO
The AM/FM antenna lead and the sublead are OK. Go to step 8.
- 8. Roof antenna check (substitution):
- 1. Substitute a known-good roof antenna .
- 2. Reconnect all the connectors, and recheck.
Does the symptom go away?
YES
Replace the original roof antenna .
NO
Replace the audio unit - Refer to: Audio Unit Removal and Installation(With Display Audio)Audio Unit Removal and Installation(With Normal Audio) .
- 9. Open wire check (SWD +B line):
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connector.
Audio unit connector D (3P) - 3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Roof antenna connector A (3P): disconnected Audio unit connector D (3P): disconnected Test point 1 Audio unit connector D (3P) No. 1 - Refer to: Audio Unit Connector for Inputs and Outputs(With Display Audio)Audio Unit Connector for Inputs and Outputs(With Normal Audio) Test point 2 Roof antenna connector A (3P) No. 1 Is there continuity?
YES
The SWD +B wire is not open. Go to step 10.
NO
Repair an open in the wire between the audio unit and the roof antenna.
- 10. Shorted wire check (SWD +B line):
- 1. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Roof antenna connector A (3P): disconnected Audio unit connector D (3P): disconnected Test point 1 Roof antenna connector A (3P) No. 1 Test point 2 Body ground Is there continuity?
YES
Repair a short to body ground in the wire between the audio unit and the roof antenna.
NO
Replace the audio unit - Refer to: Audio Unit Removal and Installation(With Display Audio)Audio Unit Removal and Installation(With Normal Audio) .
