Audio System Symptom Troubleshooting - Poor AM or FM radio reception or interference (With Navigation)

Audio System Symptom Troubleshooting - Poor AM or FM radio reception or interference

Poor AM or FM radio reception or interference

NOTE:

Check the vehicle 12 volt battery condition first.

Check for aftermarket accessories plugged into the vehicle accessory power sockets.

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

Check the connectors for poor connections or loose terminals.

Problem verification:

Problem verification

?1.	Park the vehicle in an open area.

?2.	Turn the vehicle to the ON mode.

?3.	Turn on the audio system, and select AM or FM radio station.

Is the sound quality normal?


	YES

Intermittent failure, the system is OK at this time.?


	NO

The failure is duplicated, go to step 2.

Seek stop test:

Seek stop test

?1.	Do the Seek Stop Test in the Sound Quality Diagnosis.

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 3.

Determine possible failure area (charging system and ignition system, others):

Determine possible failure area (charging system and ignition system, others)

?1.	Start the engine.

?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 4.

Determine possible failure area (SWD +B line, AM/FM line):

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, and turn on the audio system.

?4.

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 5.


	NO

Go to step 10.

Shorted wire check (AM/FM line):

Shorted wire check (AM/FM line)

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.

Disconnect the following connector.

Audio-navigation unit connector E (3P)

?3.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Roof antenna connector A (3P): disconnected
	Audio-navigation unit connector E (3P): disconnected
Test point 1	Audio-navigation unit connector E (3P) No. 2
Test point 2	Body ground

Is there continuity?


	YES

Replace the antenna main lead and/or the sublead.?


	NO

The AM/FM wire is not shorted to ground. Go to step 6.

Shorted wire check (AM/FM line to SH (AM/FM) line):

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-navigation unit connector E (3P): disconnected
Test point 1	Audio-navigation unit connector E (3P) No. 2
Test point 2	Audio-navigation unit connector E (3P) No. 3

Is there continuity?


	YES

Replace the antenna main lead and/or the sublead.?


	NO

The AM/FM wire is not shorted to the SH (AM/FM) wire. Go to step 7.

Open wire check (AM/FM line):

Open 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-navigation unit connector E (3P): disconnected
Test point 1	Audio-navigation unit connector E (3P) No. 2
Test point 2	Roof antenna connector A (3P) No. 2

Is there continuity?


	YES

The AM/FM wire is OK. Go to step 8.


	NO

Replace the antenna main lead and/or the sublead.?

Open wire check (SH (AM/FM) line):

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-navigation unit connector E (3P): disconnected
Test point 1	Audio-navigation unit connector E (3P) No. 3
Test point 2	Roof antenna connector A (3P) No. 3

Is there continuity?


	YES

The SH (AM/FM) wire is OK. Go to step 9.


	NO

Replace the antenna main lead and/or the sublead.?

Roof antenna check (substitution):

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-navigation unit.?

10.

Shorted wire check (SWD +B line):

Shorted wire check (SWD +B line)

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.

Disconnect the following connector.

Audio-navigation unit connector E (3P)

?3.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Roof antenna connector A (3P): disconnected
	Audio-navigation unit connector E (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-navigation unit and the roof antenna.?


	NO

The SWD +B wire is not shorted to ground. Go to step 11.

11.

Open wire check (SWD +B line):

Open 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-navigation unit connector E (3P): disconnected
Test point 1	Audio-navigation unit connector E (3P) No. 1
Test point 2	Roof antenna connector A (3P) No. 1

Is there continuity?


	YES

Replace the audio-navigation unit.?


	NO

Repair an open in the wire between the audio-navigation unit and the roof antenna.?