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Home >> Honda >> 2021 >> CR-V EX-L, AWD >> Repair and Diagnosis >> Accessories & Equipment >> Infotainment >> Audio System - Testing & Troubleshooting (Except Hybrid) >> Symptom Troubleshooting >> Audio System Symptom Troubleshooting >> Booming sound while driving with audio system on or off

Booming sound while driving with audio system on or off

NOTE: 

  1. Problem verification

    -1. Make sure all doors, hood, and the tailgate are closed.

    -2. Start the engine.

    Is a booming sound or a low-frequency hum heard from speakers?

    YES 

    The failure is duplicated, go to step 2.

    NO 

    Intermittent failure, the system is OK at this time.

  2. Determine possible failure area (speaker output circuit, others)

    -1. Go into the System Diagnostic Mode, and use the speaker check mode .

    Is the sound quality normal at each speaker?

    YES 

    Go to step 3.

    NO 

    Go to No sound is heard from all the speakers (display is normal) troubleshooting .

  3. Open wire check (+B BACK UP line)

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

    -2. Disconnect the following connector.

    ANC/active sound control unit 20P connector

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

    Test condition Vehicle OFF (LOCK) mode
      ANC/active sound control unit 20P connector: disconnected
    Test point 1 ANC/active sound control unit 20P connector No. 11
    Test point 2 Body ground

    Is there battery voltage?

    YES 

    The +B BACK UP wire is OK. Go to step 4.

    NO 

    Repair an open in the wire.

  4. Open wire check (IG1 METER line)

    -1. Turn the vehicle to the ON mode.

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

    Test condition Vehicle ON mode
      ANC/active sound control unit 20P connector: disconnected
    Test point 1 ANC/active sound control unit 20P connector No. 12
    Test point 2 Body ground

    Is there battery voltage?

    YES 

    The IG1 METER wire is OK. Go to step 5.

    NO 

    Repair an open in the wire.

  5. Determine possible failure area (SWD+B line, others)

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

    Test condition Vehicle ON mode
      ANC/active sound control unit 20P connector: disconnected
    Test point 1 ANC/active sound control unit 20P connector No. 3
    Test point 2 Body ground

    Is there battery voltage?

    YES 

    The SWD+B wire is OK. Go to step 8.

    NO 

    Go to step 6.

  6. Open wire check (SWD+B line)

    -1. Disconnect the following connector.

    Stereo amplifier connector C (16P) (with stereo amplifier)

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

    Test condition Vehicle ON mode
      ANC/active sound control unit 20P connector: disconnected Stereo amplifier connector C (16P) (with stereo amplifier): disconnected
    Test point 1 Audio-navigation unit connector A (24P) (with navigation) No. 21
      Audio unit connector A (24P) (without navigation) No. 21
    Test point 2 Body ground

    Is there battery voltage?

    YES 

    Repair an open in the wire.

    NO 

    The SWD+B wire is not open. Go to step 7.

  7. Shorted wire check (SWD+B line)

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

    -2. Disconnect the following connector.

    Audio-navigation unit connector A (24P) (with navigation)Audio unit connector A (24P) (without navigation)

    -3. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      ANC/active sound control unit 20P connector: disconnected Stereo amplifier connector C (16P) (with stereo amplifier): disconnected Audio-navigation unit connector A (24P) (with navigation): disconnected Audio unit connector A (24P) (without navigation): disconnected
    Test point 1 Audio-navigation unit connector A (24P) (with navigation) No. 21
      Audio unit connector A (24P) (without navigation) No. 21
    Test point 2 Body ground

    Is there continuity?

    YES 

    Repair a short to body ground in the wire.

    NO: With navigation

    Replace the audio-navigation unit .

    NO: Without navigation

    Replace the audio unit .

  8. Open wire check (GND line)

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

    -2. Reconnect the following connector.

    ANC/active sound control unit 20P connector

    -3. Turn the vehicle to the ON mode.

    -4. Measure the voltage between test points 1 and 2.

    Test condition Vehicle ON mode
    Test point 1 ANC/active sound control unit 20P connector No. 1
    Test point 2 Body ground

    Is there less than 0.2 V?

    YES 

    The GND wire is OK. Go to step 9.

    NO 

    Repair an open or high resistance in the wire or poor ground (G402).

  9. Determine possible failure area (MIC PWR line, others)

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

    -2. Disconnect the following connector.

    Front ANC/active sound control microphone 8P connector

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

    Test condition Vehicle ON mode
      Front ANC/active sound control microphone 8P connector: disconnected
    Test point 1 Front ANC/active sound control microphone 8P connector No. 4
    Test point 2 Body ground

    Is there about 8.0 V?

    YES 

    The MIC PWR wire is OK. Go to step 12.

    NO 

    Go to step 10.

  10. Open wire check (MIC PWR line)

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

    Test condition Vehicle ON mode
      Front ANC/active sound control microphone 8P connector: disconnected
    Test point 1 Audio-navigation unit connector C (36P) (with navigation) No. 7
      Audio unit connector C (36P) (without navigation) No. 7
    Test point 2 Body ground

    Is there about 8.0 V?

    YES 

    Repair an open in the wire.

    NO 

    The MIC PWR wire is not open. Go to step 11.

  11. Shorted wire check (MIC PWR line)

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

    -2. Disconnect the following connector.

    Audio-navigation unit connector C (36P) (with navigation)Audio unit connector C (36P) (without navigation)

    -3. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      Front ANC/active sound control microphone 8P connector: disconnected Audio-navigation unit connector C (36P) (with navigation): disconnected Audio unit connector C (36P) (without navigation): disconnected
    Test point 1 Audio-navigation unit connector C (36P) (with navigation) No. 7
      Audio unit connector C (36P) (without navigation) No. 7
    Test point 2 Body ground

    Is there continuity?

    YES 

    Repair a short to body ground in the wire.

    NO: With navigation

    Replace the audio-navigation unit .

    NO: without navigation

    Replace the audio unit .

  12. Determine possible failure area (ANC F MIC+8V line, others)

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

    -2. Turn the vehicle to the ON mode.

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

    Test condition Vehicle ON mode
      Front ANC/active sound control microphone 8P connector: disconnected
    Test point 1 Front ANC/active sound control microphone 8P connector No. 8
    Test point 2 Body ground

    Is there about 8.0 V?

    YES 

    The ANC F MIC+8V wire is OK. Go to step 16.

    NO 

    Go to step 13.

  13. Open wire check (ANC F MIC+8V line)

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

    Test condition Vehicle ON mode
      Front ANC/active sound control microphone 8P connector: disconnected
    Test point 1 ANC/active sound control unit 20P connector No. 18
    Test point 2 Body ground

    Is there about 8.0 V?

    YES 

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

    NO 

    The ANC F MIC+8V wire is not open. Go to step 14.

  14. Shorted wire check (ANC F MIC+8V line)

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

    -2. Disconnect the following connector.

    ANC/active sound control unit 20P connector

    -3. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      Front ANC/active sound control microphone 8P connector: disconnected ANC/active sound control unit 20P connector: disconnected
    Test point 1 ANC/active sound control unit 20P connector No. 18
    Test point 2 Body ground

    Is there continuity?

    YES 

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

    NO 

    The ANC F MIC+8V wire is not shorted to ground. Go to step 15.

  15. Shorted wire check (SH ANC F MIC line to ANC F MIC+8V line)

    -1. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      Front ANC/active sound control microphone 8P connector: disconnected ANC/active sound control unit 20P connector: disconnected
    Test point 1 ANC/active sound control unit 20P connector No. 7
    Test point 2 ANC/active sound control unit 20P connector No. 18

    Is there continuity?

    YES 

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

    NO 

    Replace the ANC/active sound control unit .

  16. Open wire check (MIC GND line)

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

    -2. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      Front ANC/active sound control microphone 8P connector: disconnected
    Test point 1 Front ANC/active sound control microphone 8P connector No. 1
    Test point 2 Body ground

    Is there continuity?

    YES 

    The MIC GND wire is OK. Go to step 17.

    NO 

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

  17. Determine possible failure area (front ANC/active sound control microphone, others)

    -1. Reconnect the following connector.

    Front ANC/active sound control microphone 8P connector

    -2. Turn the vehicle to the ON mode.

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

    NOTE:  Use the voltmeter in AC range.

    Test condition Vehicle ON mode, make a loud noise like clapping your hands in front of the front ANC/active sound control microphone.
    Test point 1 ANC/active sound control unit 20P connector No. 18
    Test point 2 ANC/active sound control unit 20P connector No. 7

    Does the voltage change when making a loud noise in front of the microphone?

    YES 

    Go to step 18.

    NO 

    Replace the front ANC/active sound control microphone .

  18. Determine possible failure area (ANC R MIC circuit, others)

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

    -2. Disconnect the following connector.

    Rear ANC/active sound control microphone 2P connector

    -3. Turn the vehicle to the ON mode.

    -4. Measure the voltage between test points 1 and 2.

    Test condition Vehicle ON mode
      Rear ANC/active sound control microphone 2P connector: disconnected
    Test point 1 Rear ANC/active sound control microphone 2P connector No. 1
    Test point 2 Rear ANC/active sound control microphone 2P connector No. 2

    Is there about 8.0 V?

    YES 

    Go to step 23.

    NO 

    Go to step 19.

  19. Open wire check (SH ANC R MIC line)

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

    -2. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      Rear ANC/active sound control microphone 2P connector: disconnected
    Test point 1 Rear ANC/active sound control microphone 2P connector No. 2
    Test point 2 Body ground

    Is there continuity?

    YES 

    The SH ANC R MIC wire is not open. Go to step 20.

    NO 

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

  20. Open wire check (ANC R MIC+8V line)

    -1. Turn the vehicle to the ON mode.

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

    Test condition Vehicle ON mode
      Rear ANC/active sound control microphone 2P connector: disconnected
    Test point 1 ANC/active sound control unit 20P connector No. 17
    Test point 2 Body ground

    Is there about 8.0 V?

    YES 

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

    NO 

    The ANC R MIC+8V wire is not open. Go to step 21.

  21. Shorted wire check (ANC R MIC+8V line)

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

    -2. Disconnect the following connector.

    ANC/active sound control unit 20P connector

    -3. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      Rear ANC/active sound control microphone 2P connector: disconnected ANC/active sound control unit 20P connector: disconnected
    Test point 1 ANC/active sound control unit 20P connector No. 17
    Test point 2 Body ground

    Is there continuity?

    YES 

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

    NO 

    The ANC R MIC+8V wire is not shorted to ground. Go to step 22.

  22. Shorted wire check (SH ANC R MIC line to ANC R MIC+8V line)

    -1. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      Rear ANC/active sound control microphone 2P connector: disconnected ANC/active sound control unit 20P connector: disconnected
    Test point 1 ANC/active sound control unit 20P connector No. 6
    Test point 2 ANC/active sound control unit 20P connector No. 17

    Is there continuity?

    YES 

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

    NO 

    Replace the ANC/active sound control unit .

  23. Determine possible failure area (rear ANC/active sound control microphone, others)

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

    -2. Reconnect the following connector.

    Rear ANC/active sound control microphone 2P connector

    -3. Turn the vehicle to the ON mode.

    -4. Measure the voltage between test points 1 and 2.

    NOTE:  Use the voltmeter in AC range.

    Test condition Vehicle ON mode, make a loud noise like clapping your hands in front of the rear ANC/active sound control microphone.
    Test point 1 ANC/active sound control unit 20P connector No. 17
    Test point 2 ANC/active sound control unit 20P connector No. 6

    Does the voltage change when making a loud noise in front of the microphone?

    YES 

    Go to step 24.

    NO 

    Replace the rear ANC/active sound control microphone .

  24. Shorted wire check (ANC lines) 1

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

    -2. Disconnect the following connectors.

    ANC/active sound control unit 20P connector Stereo amplifier connector C (16P) (with stereo amplifier)Audio-navigation unit connector C (32P) (without stereo amplifier and with navigation)Audio unit connector C (32P) (without stereo amplifier and without navigation)

    -3. Check for continuity between these test points and body ground individually.

    Test condition Vehicle OFF (LOCK) mode
      ANC/active sound control unit 20P connector: disconnected Stereo amplifier connector C (16P) (with stereo amplifier): disconnected Audio-navigation unit connector C (32P) (without stereo amplifier and with navigation): disconnected Audio unit connector C (32P) (without stereo amplifier and without navigation): disconnected
    Connector Terminal
    ANC/active sound control unit 20P connector No. 9
    No. 10
    No. 19
    No. 20

    Is there continuity?

    YES 

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

    NO 

    The ANC wires are not shorted to ground. Go to step 25.

  25. Shorted wire check (ANC lines) 2

    -1. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      ANC/active sound control unit 20P connector: disconnected Stereo amplifier connector C (16P) (with stereo amplifier): disconnected Audio-navigation unit connector C (32P) (without stereo amplifier and with navigation): disconnected Audio unit connector C (32P) (without stereo amplifier and without navigation): disconnected
    Test point 1:ANC/active sound control unit 20P connector Test points 2:ANC/active sound control unit 20P connector
    No. 8 No. 9, No. 10, No. 19, No. 20
    No. 9 No. 10, No. 19, No. 20
    No. 10 No. 19, No. 20
    No. 19 No. 20

    Is there continuity between any of the terminals?

    YES 

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

    NO 

    The ANC wires are not shorted in the wires. Go to step 26.

  26. Open wire check (ANC lines)

    -1. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      ANC/active sound control unit 20P connector: disconnected Stereo amplifier connector C (16P) (with stereo amplifier): disconnected Audio-navigation unit connector C (32P) (without stereo amplifier and with navigation): disconnected Audio unit connector C (32P) (without stereo amplifier and without navigation): disconnected

    With stereo amplifier 

    Test point 1:ANC/active sound control unit 20P connector Test point 2:Stereo amplifier connector C (16P)
    No. 9 No. 1
    No. 10 No. 2
    No. 19 No. 9
    No. 20 No. 10

    Without stereo amplifier and with navigation 

    Test point 1:ANC/active sound control unit 20P connector Test point 2:Audio-navigation unit connector C (36P)
    No. 9 No. 2
    No. 10 No. 18
    No. 19 No. 1
    No. 20 No. 17

    Without stereo amplifier and without navigation 

    Test point 1:ANC/active sound control unit 20P connector Test point 2:Audio unit connector C (32P)
    No. 9 No. 2
    No. 10 No. 18
    No. 19 No. 1
    Test point 1:ANC/active sound control unit 20P connector Test point 2:Audio unit connector C (32P)
    No. 20 No. 17

    Is there continuity?

    YES 

    The ANC wires are OK. Go to step 27.

    NO 

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

  27. Open wire check (F-CAN lines)

    -1. Jump the SCS line with the HDS, and wait more than 1 minute.

    -2. Disconnect the following connector.

    PCM connector A (50P) (1.5 L engine)PCM connector A (51P) (2.4 L engine)

    -3. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      ANC/active sound control unit 20P connector: disconnected Stereo amplifier connector C (16P) (with stereo amplifier): disconnected Audio-navigation unit connector C (32P) (without stereo amplifier and with navigation): disconnected Audio unit connector C (32P) (without stereo amplifier and without navigation): disconnected PCM connector A (50P) (1.5 L engine): disconnected PCM connector A (51P) (2.4 L engine): disconnected
    Test point 1 PCM connector A (50P) (1.5 L engine) No. 39
      PCM connector A (51P) (2.4 L engine) No. 2
    Test point 2 ANC/active sound control unit 20P connector No. 4
    Test point 1 PCM connector A (50P) (1.5 L engine) No. 38
      PCM connector A (51P) (2.4 L engine) No. 1
    Test point 2 ANC/active sound control unit 20P connector No. 5

    Is there continuity?

    YES 

    The F-CAN wires are OK. Go to step 28.

    NO 

    Repair an open in the wire(s).

  28. ANC/active sound control unit check (substitution)

    -1. Substitute a known-good ANC/active sound control unit .

    -2. Reconnect all the connectors, and recheck.

    Does the symptom go away?

    YES 

    Replace the original ANC/active sound control unit .

    NO: with stereo amplifier

    Replace the stereo amplifier .

    NO: without stereo amplifier and with navigation

    Replace the audio-navigation unit .

    NO: without stereo amplifier and without navigation

    Replace the audio unit .