Poor or no sound with AM/FM radio

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.

1. Problem verification

   -1. Park the vehicle in an open area.

   -2. Turn the vehicle to the ON mode.

   -3. Turn on the audio system, and select AM or FM radio station.

   Is the sound quality normal?

   YES 

   Intermittent failure, the system is OK at this time.

   NO 

   The failure is duplicated, go to step 2.

2. Reception/interference check

   -1. Check if the radio reception/interference is the same as the known-good vehicle in several locations.

   Is the AM or FM sound quality the same?

   YES 

   Multipath interference or weak station. Operation is normal.

   NO 

   Go to step 3.

3. Seek stop test

   -1. Select the SCAN to check if the number of received radio station are the same as the known-good vehicle.

   Are the number of radio station the same?

   YES 

   Go to step 11.

   NO 

   Go to step 4.

4. Determine possible failure area (ANT +B line, others)

   -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. 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) (male terminals) No. 1:
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there about 9.0 V?

   YES 

   The ANT +B wire is OK. Go to step 7.

   NO 

   Go to step 5.

5. Shorted wire check (ANT +B line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the following connector.

   Tuner unit connector C (5P)

   -3. Measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Roof antenna connector A (3P): disconnected
   	Tuner unit connector C (5P): disconnected
   Test point 1	Tuner unit connector C (5P) No. 1
   Test point 2	Body ground

   Is there 1.0 MΩ or more?

   YES 

   The ANT +B wire is not shorted to ground. Go to step 6.

   NO 

   Repair a short to body ground in the wire.

6. Open wire check (ANT +B line)

   -1. Measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Roof antenna connector A (3P): disconnected
   	Tuner unit connector C (5P): disconnected
   Test point 1	Tuner unit connector C (5P) No. 1
   Test point 2	Roof antenna connector A (3P) (male terminals) No. 1:

   Courtesy of HONDA, U.S.A., INC.

   Is there 1.0 Ω or less?

   YES 

   Replace the tuner unit .

   NO 

   Repair an open in the wire.

7. Shorted wire check (RF IN line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the following connector.

   Tuner unit connector C (5P)

   -3. Measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Roof antenna connector A (3P): disconnected
   	Tuner unit connector C (5P): disconnected
   Test point 1	Tuner unit connector C (5P) No. 2
   Test point 2	Body ground

   Is there 1.0 MΩ or more?

   YES 

   The RF IN wire is not shorted to ground. Go to step 8.

   NO 

   There is a short to body ground in the wire. Replace the affected antenna lead.

8. Shorted wire check (RF IN line to SH (RF IN) line)

   -1. Measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Roof antenna connector A (3P): disconnected
   	Tuner unit connector C (5P): disconnected
   Test point 1	Tuner unit connector C (5P) No. 2
   Test point 2	Tuner unit connector C (5P) No. 4

   Is there 1.0 MΩ or more?

   YES 

   The RF IN wire is not shorted to SH (RF IN) wire. Go to step 9.

   NO 

   There is a short in the wire. Replace the affected antenna lead.

9. Open wire check (RF IN line)

   -1. Measure the resistance between test points 1 and 2.

   Test condition

   Vehicle OFF (LOCK) mode

   	Roof antenna connector A (3P): disconnected
   	Tuner unit connector C (5P): disconnected
   Test point 1	Tuner unit connector C (5P) No. 2
   Test point 2	Roof antenna connector A (3P) (male terminals) No. 2:

   Courtesy of HONDA, U.S.A., INC.

   Is there 1.0 Ω or less?

   YES 

   The RF IN wire is OK. Go to step 10.

   NO 

   There is an open in the wire. Replace the affected antenna lead.

10. 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 tuner unit .

11. Shorted wire check (SPDIF1 SIG line)

    -1. Turn the vehicle to the OFF (LOCK) mode.

    -2. Disconnect the following connectors.

    Audio-navigation unit connector L (2P) (with navigation)

    Audio unit connector L (2P) (without navigation)

    Tuner unit connector B (2P)

    -3. Measure the resistance between test points 1 and 2.

    Test condition	Vehicle OFF (LOCK) mode
    	Audio-navigation unit connector L (2P) (with navigation): disconnected
    	Audio unit connector L (2P) (without navigation): disconnected
    	Tuner unit connector B (2P): disconnected
    Test point 1	Tuner unit connector B (2P) No. 1
    Test point 2	Body ground

    Is there 1.0 MΩ or more?

    YES 

    The SPDIF1 wire is not shorted to ground. Go to step 12.

    NO 

    There is a short to body ground in the wire. Replace the affected shielded harness.

12. Shorted wire check (SPDIF1 SIG line to SPDIF1 SH line)

    -1. Measure the resistance between test points 1 and 2.

    Test condition	Vehicle OFF (LOCK) mode
    	Audio-navigation unit connector L (2P) (with navigation): disconnected
    	Audio unit connector L (2P) (without navigation): disconnected
    	Tuner unit connector B (2P): disconnected
    Test point 1	Tuner unit connector B (2P) No. 1
    Test point 2	Tuner unit connector B (2P) No. 2

    Is there 1.0 MΩ or more?

    YES 

    The SPDIF1 SIG and the SPDIF1 SH wires are not shorted. Go to step 13.

    NO 

    There is a short in the wires. Replace the affected shielded harness.

13. Open wire check (SPDIF1 SIG line, SPDIF1 SH line)

    -1. Measure the resistance between test points 1 and 2.

    Test condition	Vehicle OFF (LOCK) mode
    	Audio-navigation unit connector L (2P) (with navigation): disconnected
    	Audio unit connector L (2P) (without navigation): disconnected
    	Tuner unit connector B (2P): disconnected
    Test point 1	Audio-navigation unit connector L (2P) (with navigation) No. 1
    	Audio unit connector L (2P) (without navigation) No. 1
    Test point 2	Tuner unit connector B (2P) No. 1

    Test point 1	Audio-navigation unit connector L (2P) (with navigation) No. 2
    	Audio unit connector L (2P) (without navigation) No. 2
    Test point 2	Tuner unit connector B (2P) No. 2

    Is there 1.0 Ω or less?

    YES 

    The SPDIF1 SIG and the SPDIF1 SH wires are OK. Go to step 14.

    NO 

    There is an open in the wire(s). Replace the affected shielded harness.

14. Tuner unit check (substitution)

    -1. Substitute a known-good tuner unit .

    -2. Reconnect all the connectors, and recheck.

    Does the symptom go away?

    YES 

    Replace the original tuner unit .

    NO: With navigation

    Replace the audio-navigation unit .

    NO: Without navigation

    Replace the audio unit .