Poor AM or FM Radio Reception or Interference

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

NOTE:

Check the vehicle battery condition first.
Check the connectors for poor connections or loose terminals.
Check the radio reception in an open area. Poor reception/interference can be caused by any of these conditions:
- The radio station is far away.
- A tall building, mountains, or high-voltage power lines are nearby.
- Aftermarket window tint.
- Atmospheric conditions are unfavorable.

Turn the ignition switch to ON (II).
Do SEEK STOP TEST .
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 as the known-good vehicle in several different locations.
Is the reception/interference the same as a known-good vehicle in several different locations?

YES - Go to step 4.

NO - Multipath interference or weak station. Operation is normal. ■
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, fuel injection system (fuel pump), HVAC (blower motor), and the ignition system. ■

NO - Go to step 5.
Turn the ignition switch to LOCK (0).
Remove the right quarter pillar trim (see TRIM REMOVAL/INSTALLATION - REAR SIDE AREA ).
Check the connections from the AM/FM antenna amplifier to the window antenna.
Are there any loose or damaged connections?

YES - Repair the connections, or substitute a known-good AM/FM antenna amplifier (see AM/FM ANTENNA AMPLIFIER REPLACEMENT ) and retest. If the symptom/condition goes away, replace the original AM/FM antenna amplifier. ■

NO - Go to step 8.
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.

Fig 1: Identifying Strong Flashlight & Antenna Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Are there any breaks or cuts in the antenna?

YES - Repair the window antenna. Go to AM/FM antenna repair (see ), or replace the right quarter glass (see QUARTER GLASS REPLACEMENT ) if the damaged section is too long. ■

NO - Go to step 9.
Disconnect the AM/FM antenna amplifier 3P connector.
Turn the ignition switch to ON (II).
Turn on the audio unit.
Measure the voltage between AM/FM antenna amplifier 3P connector terminal No. 3 and body ground.
Is there battery voltage?

YES - Go to 18.

NO - Go to step 13.
Turn the ignition switch to LOCK (0).
Remove the audio unit (see AUDIO UNIT REMOVAL/INSTALLATION ).
Disconnect audio unit connector G (3P).
Check for continuity between audio unit connector G (3P) terminal No. 3 and body ground.
Is there continuity?

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

NO - Go to step 17.

Fig 2: Checking Continuity Between Audio Unit Connector G (3P) Terminal No. 3 & Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between audio unit connector G (3P) terminal No. 3 and AM/FM antenna amplifier 3P connector terminal No. 3.
Is there continuity?

YES - Audio unit is faulty, replace the audio unit (see AUDIO UNIT REMOVAL/INSTALLATION ). ■

NO - Repair open in the wire between the audio unit and the AM/FM antenna amplifier. Also check the antenna lead/sublead connector. ■

Fig 3: Checking Continuity Between Audio Unit Connector G (3P) Terminal 3 & AM/FM Antenna Amplifier 3P Connector Terminal 3
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch to LOCK (0).
Remove the audio unit (see AUDIO UNIT REMOVAL/INSTALLATION ).
Disconnect audio unit connector G (3P).
Check for continuity between audio unit connector G (3P) terminal No. 1 and body ground.
Is there continuity?

YES - AM/FM antenna lead and/or sublead is shorted. Replace the shielded AM/FM antenna lead and/or sublead. ■

NO - Go to step 22.

Fig 4: Checking Continuity Between Audio Unit Connector G (3P) Terminal 1 & Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between audio unit connector G (3P) terminal No. 1 and AM/FM antenna amplifier 3P connector terminal No. 1.
Is there continuity?

YES - Go to step 21.

NO - AM/FM antenna lead and/or sublead is open. Replace the shielded AM/FM antenna lead and/or sublead. ■

Fig 5: Checking Continuity Between Audio Unit Connector G (3P) Terminal 1 & AM/FM Antenna Amplifier 3P Connector Terminal 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between audio unit connector G (3P) terminal No. 2 and AM/FM antenna amplifier 3P connector terminal No. 2.
Is there continuity?

YES - Go to step 24.

NO - AM/FM antenna lead and/or sublead is open. Replace the AM/FM antenna lead and/or sublead. ■

Fig 6: Checking Continuity Between Audio Unit Connector G (3P) Terminal 2 & AM/FM Antenna Amplifier 3P Connector Terminal 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between audio unit connector G (3P) terminals No. 1 and No. 2.
Is there continuity?

YES - Substitute a known-good AM/FM antenna amplifier (see AM/FM ANTENNA AMPLIFIER REPLACEMENT ) and recheck. If the reception is normal, replace the original AM/FM antenna amplifier. If the reception is still poor, replace the audio unit (see AUDIO UNIT REMOVAL/INSTALLATION ). ■

NO - AM/FM antenna lead and/or sublead is shorted. Replace the AM/FM antenna lead and/or sublead. ■

Fig 7: Checking Continuity Between Audio Unit Connector G (3P) Terminals 1 & 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.