Poor AM or FM radio reception or interference

NOTE:

Check the vehicle battery condition first.
Check the radio reception in an open area. Compare it to a known-good vehicle whenever possible. 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.
- Aftermarket window tinting or electronic accessories.

Turn the ignition switch ON (II).
Do the seek stop test (see 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 in several locations.
Is the reception/interference the same?

YES - Go to step 4.

NO - Multi path interference or weak station. Operation is normal.
Check the reception/interference when the rear window defogger is on.
Is the reception poor with the rear window defogger on?

YES - Check for a break in the rear window defogger grid (see FUNCTION TEST ), a poor connection, or a faulty AM/FM antenna amplifier-rear window defogger coil (see AM/FM ANTENNA AMPLIFIER-REAR WINDOW DEFOGGER COIL REPLACEMENT ).

NO - Go to step 5.
Start the engine.
Check to see if the problem is interference.
Is there noise (static or while) 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 7.
Turn the ignition switch to LOCK (0).
Wrap aluminum foil (A) around the tip of a tester probe (B) as shown.

Fig 1: Identifying Aluminum Foil Of Tester Probe
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity by touching one tester probe to the window antenna terminal (A), and move the other tester probe along the antenna wires.

Fig 2: Identifying Window Antenna Terminal
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity in all sections of the antenna?

YES - Go to step 10.

NO - Repair the antenna wires (see AM/FM ANTENNA REPAIR ).
Turn the ignition switch ON (II).
Turn on the audio unit.
Measure the voltage between AM/FM antenna amplifier-rear window defogger coil connector B terminal 1 and body ground.

Fig 3: Measuring Voltage Between AM/FM Antenna Amplifier-Rear Window Defogger Coil Connector B Terminal 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES - Go to step 13.

NO - Go to step 21.
Turn the ignition switch to LOCK (0).
Remove the audio-HVAC display module, and disconnect the AM/FM antenna sublead jack.
NOTE: Eject all the discs before removing the audio unit to prevent damaging the CD player's load mechanism.
Disconnect the AM/FM antenna lead from the AM/FM antenna amplifier-rear window defogger coil.
Check for continuity between the AM/FM antenna sublead center pin at the audio unit and the AM/FM antenna lead center pin at the AM/FM antenna amplifier-rear window defogger coil.

Fig 4: Checking Continuity Between AM/FM Antenna Sublead Center Pin Audio Unit And AM/FM Antenna Lead Center Pin
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to step 17.

NO - Replace the AM/FM antenna lead and/or sublead.
Check for continuity between the AM/FM antenna sublead shield surface of the audio unit side and the AM/FM antenna lead shield surface of the AM/FM antenna amplifier-rear window defogger coil side.

Fig 5: Checking Continuity Between AM/FM Antenna Sublead Shield Surface And AM/FM Antenna Lead Shield Surface
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to step 18.

NO - Replace AM/FM antenna lead and/or sublead.
Check for continuity between the AM/FM antenna sublead center pin at the audio unit and body ground.

Fig 6: Checking Continuity Between AM/FM Antenna Sublead Center Pin At Audio Unit And Body Ground
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 the AM/FM antenna sublead center pin and the surface of the audio unit.

Fig 7: Checking Continuity Between AM/FM Antenna Sublead Center Pin And Audio Unit
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

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

NO - Go to step 20.
Substitute a known-good AM/FM antenna lead and 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 audio unit and recheck. If the reception is still poor, replace the AM/FM antenna amplifier-rear window defogger coil.
Turn the ignition switch to LOCK (0).
Remove the audio-HVAC display module and disconnect the audio unit connector A (20P).
NOTE: Eject all the discs before removing the audio unit to prevent damaging the CD player's load mechanism.
Check for continuity between audio unit connector A (20P) terminal No. 1 and the AM/FM antenna amplifier-rear window defogger coil connector B terminal No. 1.

Fig 8: Checking Continuity Between Audio Unit Connector A (20P) Terminal No. 1 And Connector B Terminal No. 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Substitute a known-good audio-HVAC display module and retest.

NO - Repair open in the wire between the audio unit and the AM/FM antenna amplifier-rear window defogger coil.

Special Tools Required

Radio test harness breakout box 07AAZ-SDAA100
Radio test harness 070AZ-SEAA200