Poor AM or FM Radio Reception Or Interference (With Navigation)

WARNING: This page is about a different car, the 2011 Honda Fit, 2010 Honda Fit, and 2009 Honda Fit. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Check the vehicle battery condition first, (see BATTERY TEST )
Check the radio reception in an open area.
Compare it to a known-good vehicle of the same model, year, and trim level whenever possible.
If necessary, have the customer demonstrate the symptom.
Poor reception/interference can be caused by any of these conditions:
- The radio station is far away.
- Atmospheric conditions are unfavorable.
- Tall buildings, mountains, or high-voltage power lines are nearby.
- Electronic accessories.
- Non-standard antenna mast.
- Check for aftermarket accessories plugged into the vehicle accessory power sockets (including cell phones).
Check the connectors for poor connections or loose terminals.

Turn the ignition switch to ON (II).
Do the seek stop test (see SEEK STOP TEST ).
Does the test vehicle receive 90 % of the same stations as the known-good vehicle?

YES - Multipath interference or weak station. Operation is normal at this time.

NO - Go to step 3.
Check if the radio reception/interference is the same as the known-good vehicle in several locations.
Is the reception/interference the same as the known-good vehicle in several different locations?

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

NO - Go to step 4.
Check the reception/interference while the engine is running, and compare it to the known-good vehicle.
Is there noise (static or whine) only with the engine running?

YES - Check the antenna and radio grounds. If OK, check the charging system, the fuel injection system (fuel pump), the HVAC blower motor, and the ignition system.

NO - Go to step 5.
Turn the ignition switch to LOCK (0).
Check the antenna mast for cracks or other damage. Make sure that the AM/FM antenna is not loose.
NOTE: Do not use any tools to tighten the antenna mast.

Is there any damage?

YES - Replace the AM/FM antenna (see AM/FM Antenna Replacement ).

NO - Go to step 7.
Disconnect the antenna cable 3P connector from the AM/FM antenna (see AUDIO REMOTE SWITCH TEST ).
Turn the ignition switch to ON (II).
Measure the voltage between AM/FM antenna connector terminal No. 3 and body ground.

Fig 1: Measuring Voltage Between AM/FM Antenna 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 10.
Turn the ignition switch to LOCK (0).
Remove the audio-navigation unit (see AUDIO-NAVIGATION UNIT REMOVAL/INSTALLATION ).
Disconnect audio-navigation unit connector G (3P).
Check for continuity between audio-navigation unit connector G (3P) terminal No. 3 and AM/FM antenna 3P connector terminal No. 3.

Fig 2: Checking Continuity Between Audio-Navigation Unit Connector G (3P) Terminal No. 3 And AM/FM Antenna 3P Connector Terminal No. 3
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to step 14.

NO - There is an open in the wire between the audio-navigation unit and the AM/FM antenna.
Check for continuity between AM/FM antenna connector (3P) terminal No. 3 and body ground.

Fig 3: Checking Continuity Between AM/FM Antenna Connector (3P) Terminal No. 3 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

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

NO - Substitute a known-good audio-navigation unit, and recheck.
Remove the audio-navigation unit (see AUDIO-NAVIGATION UNIT REMOVAL/INSTALLATION ).
Check for continuity between audio-navigation unit connector G (3P) terminal No. 1 and AM/FM antenna 3P connector terminal No. 1.

Fig 4: Checking Continuity Between Audio-Navigation Unit Connector G (3P) Terminal No. 1 And AM/FM Antenna 3P Connector Terminal No. 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to step 17.

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

Fig 5: Checking Continuity Between Audio-Navigation Unit Connector G (3P) Terminal No. 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

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

NO - Go to step 18.
Check for continuity between audio-navigation unit connector G (3P) terminal No. 2 and AM/FM antenna 3P connector terminal No. 2.

Fig 6: Checking Continuity Between Audio-Navigation Unit Connector G (3P) Terminal No. 2 And AM/FM Antenna 3P Connector Terminal No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to step 19.

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

Fig 7: Checking Continuity Between Audio-Navigation Unit Connector G (3P) Terminals No. 1 And No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

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

NO - Replace the AM/FM antenna (see AM/FM Antenna Replacement ), and recheck. If the reception is still poor, replace the audio-navigation unit (see AUDIO-NAVIGATION UNIT REMOVAL/INSTALLATION ).