Booming sound while driving with audio system on or off

NOTE: 

• Check the vehicle 12 volt battery condition first .
• Check for F-CAN and B-CAN DTCs and resolve them before troubleshooting.
• Check the connectors for poor connections or loose terminals.
• Check the fuses and relays associated with the system, and check for a short in the related lines.
• The front ANC/active sound control microphone is the same parts as the front HFL-navigation-ANC/active sound control microphone and the front HFL-ANC/active sound control microphone.

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. Measure the resistance 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 1.0 MΩ or more?

   YES: With navigation

   Replace the audio-navigation unit .

   YES: Without navigation

   Replace the audio unit .

   NO 

   Repair a short to body ground in the wire.

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. Measure the resistance 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 1.0 MΩ or more?

    YES: With navigation

    Replace the audio-navigation unit .

    YES: without navigation

    Replace the audio unit .

    NO 

    Repair a short to body ground in the wire.

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. Measure the resistance 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 1.0 MΩ or more?

    YES 

    The ANC_F_MIC+8V wire is not shorted to ground. Go to step 15.

    NO 

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

15. Shorted wire check (SH_ANC_F_MIC line to ANC_F_MIC+8V line)

    -1. Measure the resistance 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 1.0 MΩ or more?

    YES 

    Replace the ANC/active sound control unit .

    NO 

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

16. Open wire check (MIC_GND line)

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

    -2. Measure the resistance 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 1.0 Ω or less?

    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. Measure the resistance 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 1.0 Ω or less?

    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. Measure the resistance 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 1.0 MΩ or more?

    YES 

    The ANC_R_MIC+8V wire is not shorted to ground. Go to step 22.

    NO 

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

22. Shorted wire check (SH_ANC_R_MIC line to ANC_R_MIC+8V line)

    -1. Measure the resistance 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 1.0 MΩ or more?

    YES 

    Replace the ANC/active sound control unit .

    NO 

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

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. Measure the resistance 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 1.0 MΩ or more?

    YES 

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

    NO 

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

25. Shorted wire check (ANC lines) 2

    -1. Measure the resistance 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 1.0 MΩ or more between any of the terminals?

    YES 

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

    NO 

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

26. Open wire check (ANC lines)

    -1. Measure the resistance 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 1.0 Ω or less?

    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. Disconnect the following connector.

    CAN gateway 16P connector

    -2. Measure the resistance 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 CAN gateway 16P connector: disconnected

    Test point 1	CAN gateway 16P connector No. 6 (female terminals):
    Test point 2	ANC/active sound control unit 20P connector No. 4

    Test point 1	CAN gateway 16P connector No. 14 (female terminals):
    Test point 2	ANC/active sound control unit 20P connector No. 5

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

    Is there 1.0 Ω or less?

    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 .