Audio System Symptom Troubleshooting - Poor AM or FM radio reception or interference (2/4-door)

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 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.

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.

Reception/interference check:

Reception/interference check

?1.	Check if the radio reception/interference is the same as the known-good vehicle in several locations.

Is the AM or FM sound quality the same?


	YES

Multipath interference or weak station. Operation is normal.?


	NO

Go to step 3.

Window antenna check:

Window antenna check

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

?2.

With the help of an assistant inside the vehicle, have the assistant shine a strong flashlight (A) along each antenna wire (B). Check from the outside of the vehicle for any breaks or openings in the antenna wires (the light shines through any breaks or cuts).

NOTE: It is easier to see the breaks if you do this test in a dark or shaded area.

Are there any breaks or cuts in the antenna wire?


	YES

Repair the window antenna. Go to window antenna repair, or replace the rear window if the damaged section is too long.?


	NO

Go to step 4.

Determine possible failure area (ANT +B line, others):

Determine possible failure area (ANT +B line, others)

?1.

Disconnect the following connector.

AM/FM antenna amplifier 3P connector

?2.	Turn the vehicle to the ON mode.

?3.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
	AM/FM antenna amplifier 3P connector: disconnected
Test point 1	AM/FM antenna amplifier 3P connector No. 1
Test point 2	Body ground

Is there battery voltage?


	YES

The ANT +B wire is OK. Go to step 7.


	NO

Go to step 5.

Shorted wire check (ANT +B line):

Shorted wire check (ANT +B line)

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

?2.

Disconnect the following connector.

Audio unit connector E (3P)

?3.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	AM/FM antenna amplifier 3P connector: disconnected
	Audio unit connector E (3P): disconnected
Test point 1	AM/FM antenna amplifier 3P connector No. 1
Test point 2	Body ground

Is there continuity?


	YES

Repair a short to body ground in the wire between the AM/FM antenna amplifier and the audio unit.?


	NO

The ANT +B wire is not shorted to ground. Go to step 6.

Open wire check (ANT +B line):

Open wire check (ANT +B line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	AM/FM antenna amplifier 3P connector: disconnected
	Audio unit connector E (3P): disconnected
Test point 1	Audio unit connector E (3P) No. 1
Test point 2	AM/FM antenna amplifier 3P connector No. 1

Is there continuity?


	YES

Replace the audio unit.?


	NO

Repair an open in the wire between the AM/FM antenna amplifier and the audio unit.?

Shorted wire check (RF IN line):

Shorted wire check (RF IN line)

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

?2.

Disconnect the following connector.

Audio unit connector E (3P)

?3.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	AM/FM antenna amplifier 3P connector: disconnected
	Audio unit connector E (3P): disconnected
Test point 1	AM/FM antenna amplifier 3P connector No. 2
Test point 2	Body ground

Is there continuity?


	YES

There is a short to body ground in the wire between the AM/FM antenna amplifier and the audio unit. Replace the affected antenna lead.?


	NO

The RF IN wire is not shorted to ground. Go to step 8.

Shorted wire check (RF IN line to SH (RF IN) line):

Shorted wire check (RF IN line to SH (RF IN) line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	AM/FM antenna amplifier 3P connector: disconnected
	Audio unit connector E (3P): disconnected
Test point 1	AM/FM antenna amplifier 3P connector No. 2
Test point 2	AM/FM antenna amplifier 3P connector No. 3

Is there continuity?


	YES

There is a short in the wire between the AM/FM antenna amplifier and the audio unit. Replace the affected antenna lead.?


	NO

The RF IN wire is not shorted to SH(RF IN) wire. Go to step 9.

Open wire check (RF IN line):

Open wire check (RF IN line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	AM/FM antenna amplifier 3P connector: disconnected
	Audio unit connector E (3P): disconnected
Test point 1	AM/FM antenna amplifier 3P connector No. 2
Test point 2	Audio unit connector E (3P) No. 2

Is there continuity?


	YES

The RF IN wire is OK. Go to step 10.


	NO

There is an open in the wire between the AM/FM antenna amplifier and the audio unit. Replace the affected antenna lead.?

10.

AM/FM antenna amplifier check (substitution):

AM/FM antenna amplifier check (substitution)

?1.	Substitute a known-good AM/FM antenna amplifier.

?2.	Reconnect all the connectors, and recheck.

Does the symptom go away?


	YES

Replace the original AM/FM antenna amplifier.?


	NO

Replace the audio unit.?