Audio System Symptom Troubleshooting - Poor AM or FM radio reception or interference (With Normal Audio) | 2012-2016 CR-V RM1/RM4,RE5/RE6 HONDA CR-V Service Manual

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.	Turn the vehicle to the ON mode.

?2.	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 2.

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

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.

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

?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.

Open wire check (AM/FM line):

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
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.?

Shorted wire check (AM/FM line):

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
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.

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 unit connector D (3P): disconnected
Test point 1	Audio unit connector D (3P) No. 3
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.?

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 unit connector D (3P): disconnected
Test point 1	Audio unit connector D (3P) No. 2
Test point 2	Audio unit connector D (3P) No. 3

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.

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 unit.?

Open wire check (SWD +B line):

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
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):

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.?