Poor AM or FM radio reception or interference (without navigation)

WARNING: This page is about a different car, the 2011 Honda Insight and 2010 Honda Insight. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Check the vehicle battery condition first (see 12 VOLT BATTERY TEST ).
Check the radio reception in an open area. Poor reception/interference can be caused by the following:
- The radio station is far away.
- A tall building, a mountain, or a high-voltage power line is nearby.
- Aftermarket window tint.
- Check for aftermarket accessories including cell phones and chargers plugged into the vehicle accessory power sockets.

Turn the ignition switch to ON (II).
Do the seek stop test (see SOUND JUDGING ), and the reception level indication in the Self-diagnostic Function (see HOW TO CHECK THE AUDIO SYSTEM CONDITION ).
Is the test vehicle within 10 % of the known-good vehicle?

YES -Multipath interference or weak station. Operation is normal.

NO -go to step 3.
Check if the radio reception/interference is the same in several locations.
Is the reception/interference the same?

YES -go to step 4.

NO -Multipath interference or weak station. Operation is normal.
Check the reception/interference while the engine is running.
Is there noise 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 5.
Turn the ignition switch to LOCK (0).
Check the AM/FM antenna mast for cracks, or other damage. Make sure that the AM/FM antenna mast isn't loose.
NOTE: Do not use any tools to tighten the AM/FM antenna mast.

Is there any damage?

YES -Replace the AM/FM antenna mast (see AM/FM ANTENNA REPLACEMENT ).

NO -go to step 7.
Disconnect the AM/FM antenna 3P connector from the AM/FM antenna.
Turn the ignition switch to ON (II).
Turn on the audio unit.
Measure the voltage between AM/FM antenna 3P connector terminal No. 3 and body ground.

Fig 1: Measuring Voltage Between AM/FM Antenna 3P Connector Terminal No. 3 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -go to step 15.

NO -go to step 11.
Turn the ignition switch to LOCK (0).
Remove the audio unit (see AUDIO UNIT REMOVAL/INSTALLATION ), and disconnect audio unit connector G (3P).
Check for continuity between audio unit connector G (3P) terminal No. 3 and AM/FM antenna 3P connector terminal No. 3.

Fig 2: Checking Continuity Between Audio Unit Connector G (3P) And AM/FM Antenna 3P Connector Terminals (Except DX Model)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 3: Checking Continuity Between Audio Unit Connector G (3P) And AM/FM Antenna 3P Connector Terminals (DX Model)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -go to step 14.

NO -Repair an open in the wire between the audio unit and the AM/FM antenna. Also check the AM/FM antenna lead/sublead connector.
Check for continuity between audio unit connector G (3P) terminal No. 3 and body ground.

Fig 4: Checking Continuity Between Audio Unit Connector G (3P) Terminal No. 3 And Body Ground (Except DX Model)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 5: Checking Continuity Between Audio Unit Connector G (3P) Terminal No. 3 And Body Ground (DX Model)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

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

NO -Replace the audio unit (see AUDIO UNIT REMOVAL/INSTALLATION ).
Turn the ignition switch to LOCK (0).
Remove the audio unit (see AUDIO UNIT REMOVAL/INSTALLATION ), and disconnect audio unit connector G (3P).
Check for continuity between audio unit connector G (3P) terminal No. 1 and AM/FM antenna 3P connector terminal No. 1.

Fig 6: Checking Continuity Between Audio Unit Connector G (3P) And AM/FM Antenna 3P Connector Terminals (Except DX Model)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 7: Checking Continuity Between Audio Unit Connector G (3P) And AM/FM Antenna 3P Connector Terminals (DX Model)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -go to step 18.

NO -Replace the AM/FM antenna lead and/or sublead.
Check for continuity between audio unit connector G (3P) terminal No. 1 and body ground.

Fig 8: Checking Continuity Between Audio Unit Connector G (3P) Terminal No. 1 And Body Ground (Except DX Model)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 9: Checking Continuity Between Audio Unit Connector G (3P) Terminal No. 1 And Body Ground (DX Model)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Replace the AM/FM antenna lead and/or sublead.

NO -go to step 19.
Check for continuity between audio unit connector G (3P) terminal No. 2 and AM/FM antenna 3P connector terminal No. 2.

Fig 10: Checking Continuity Between Audio Unit Connector G (3P) And AM/FM Antenna 3P Connector Terminals (Except DX Model)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 11: Checking Continuity Between Audio Unit Connector G (3P) And AM/FM Antenna 3P Connector Terminals (DX Model)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -go to step 20.

NO -Replace the AM/FM antenna lead and/or sublead.
Check for continuity between audio unit connector G (3P) terminals No. 1 and No. 2.

Fig 12: Checking Continuity Between Audio Unit Connector G (3P) Terminals No. 1 And No. 2 (Except DX Model)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 13: Checking Continuity Between Audio Unit Connector G (3P) Terminals No. 1 And No. 2 (DX Model)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Replace the AM/FM antenna lead and/or sublead.

NO -go to step 21.
Substitute a known-good AM/FM antenna lead and/or sublead, and check the radio reception.

Is the reception normal?

YES -Replace the AM/FM antenna lead and/or sublead.

NO -Substitute a known-good AM/FM antenna (see AM/FM ANTENNA REPLACEMENT ), and recheck. If the reception is still poor, replace the audio unit (see AUDIO UNIT REMOVAL/INSTALLATION ).