Audio System - Booming sound while driving with audio unit on or off(Without Touch Screen) (2019 2020 2021 2022)

Booming sound while driving with audio unit on or off 

NOTE: 

• Check the vehicle battery condition first .
• Check the connectors for poor connections or loose terminals.

1. Problem verification

   -1. Make sure all doors and hood 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. Self-diagnostic function check

   -1. Do the Self-Diagnostic Function, and use the ANC/active sound control system check mode .

   Does the low-frequency hum sound continue sounding for about 1 minute?

   YES 

   Go to step 22.

   NO: The low-frequency hum sound sounding for about 1 second

   Go to step 14.

   NO: The low-frequency hum sound is not heard

   Go to step 3.

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 circuit	+B BACK UP
   Test point 1	ANC/active sound control unit 20P connector No. 11 (GRN)
   Test point 2	Body ground

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

   Is there battery voltage?

   YES 

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

   NO 

   Repair an open in the wire.

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

   -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 circuit	SWD+B
   Test point 1	ANC/active sound control unit 20P connector No. 3 (WHT)
   Test point 2	Body ground

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

   Is there battery voltage?

   YES 

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

   NO 

   Go to step 5.

5. Open wire check (SWD+B line)

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

   Test condition	Vehicle ON mode
   	ANC/active sound control unit 20P connector: disconnected
   Test circuit	SWD+B
   Test point 1	Audio unit connector A (24P) No. 21 (WHT)
   Test point 2	Body ground

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

   Is there battery voltage?

   YES 

   Repair an open in the wire.

   NO 

   The SWD+B wire is not open. Go to step 6.

6. Shorted wire check (SWD+B line)

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

   -2. Disconnect the following connector.

   NOTE:  Eject the disc before disconnecting the audio unit to prevent damaging the CD player's load mechanism.

   Audio unit connector A (24P)

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

   Test condition	Vehicle OFF (LOCK) mode
   	Audio unit connector A (24P): disconnected
   	ANC/active sound control unit 20P connector: disconnected
   Test circuit	SWD+B
   Test point 1	Audio unit connector A (24P) No. 21 (WHT)
   Test point 2	Body ground

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

   Is there continuity?

   YES 

   Repair a short in the wire.

   NO 

   Replace the audio unit .

7. Determine possible failure area (ANC CHK2 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 circuit	ANC CHK2
   Test point 1	ANC/active sound control unit 20P connector No. 13 (GRN)
   Test point 2	Body ground

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

   Is there about 5.0 V?

   YES 

   The ANC CHK2 wire is OK. Go to step 10.

   NO 

   Go to step 8.

8. Open wire check (ANC CHK2 line)

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

   Test condition	Vehicle ON mode
   	ANC/active sound control unit 20P connector: disconnected
   Test circuit	ANC CHK2
   Test point 1	Audio unit connector A (24P) No. 23 (GRN)
   Test point 2	Body ground

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

   Is there about 5.0 V?

   YES 

   Repair an open in the wire.

   NO 

   The ANC CHK2 wire is not open. Go to step 9.

9. Shorted wire check (ANC CHK2 line)

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

   -2. Disconnect the following connector.

   NOTE:  Eject the disc before disconnecting the audio unit to prevent damaging the CD player's load mechanism.

   Audio unit connector A (24P)

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

   Test condition

   Vehicle OFF (LOCK) mode

   	ANC/active sound control unit 20P connector: disconnected
   	Audio unit connector A (24P): disconnected
   Test circuit	ANC CHK2
   Test point 1	Audio unit connector A (24P) No. 23 (GRN)
   Test point 2	Body ground

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

   Is there continuity?

   YES 

   Repair an short in the wire.

   NO 

   Replace the audio unit .

10. Open wire check (GND line)

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

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

    Test condition	Vehicle ON mode
    	ANC/active sound control unit 20P connector: disconnected
    Test circuit	GND
    Test point 1	ANC/active sound control unit 20P connector No. 1 (BLK)
    Test point 2	Body ground

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

    Is there continuity?

    YES 

    The GND wire is OK. Go to step 11.

    NO 

    Repair an open in the wire or poor ground (G506).

11. Shorted wire check (ANC lines)

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

    -2. Disconnect the following connector.

    NOTE:  Eject the disc before disconnecting the audio unit to prevent damaging the CD player's load mechanism.

    Audio unit connector A (24P)

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

    Test condition	Vehicle OFF (LOCK) mode
    	Audio unit connector A (24P): disconnected
    	ANC/active sound control unit 20P connector: disconnected

    Connector	Test circuit	Terminal
    ANC/active sound control unit 20P connector	ANC R-	No. 9 (GRN)
    	ANC F-	No. 10 (WHT)
    	ANC R+	No. 19 (BLK)
    	ANC L+	No. 20 (RED)

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

    Is there continuity?

    YES 

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

    NO 

    The ANC wires are not shorted to ground. Go to step 12.

12. Open wire check (ANC lines)

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

    Test condition	Vehicle OFF (LOCK) mode
    	Audio unit connector A (24P): disconnected
    	ANC/active sound control unit 20P connector: disconnected

    Test circuit	Test point 1:ANC/active sound control unit 20P connector	Test point 2:Audio unit connector A (24P)
    ANC R-	No. 9 (GRN)	No. 8 (GRN)
    ANC F-	No. 10 (WHT)	No. 18 (WHT)
    ANC R+	No. 19 (BLK)	No. 7 (BLK)
    ANC F+	No. 20 (RED)	No. 17 (RED)

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

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

    Is there continuity?

    YES 

    The ANC wires are OK. Go to step 13.

    NO 

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

13. ANC/active sound control unit check

    -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 

    Replace the audio unit .

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

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

    -2. Disconnect the following connector.

    HFL-ANC/active sound control microphone 8P connector

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

    Test condition	Vehicle OFF (LOCK) mode
    	HFL-ANC/active sound control microphone 8P connector: disconnected
    Test circuit	+B BACK UP
    Test point 1	HFL-ANC/active sound control microphone 8P connector No. 5 (GRN)
    Test point 2	Body ground

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

    Is there battery voltage?

    YES 

    The +B BACK UP wire is OK. Go to step 15.

    NO 

    Repair an open in the wire.

15. Open wire check (ACC line)

    -1. Turn the vehicle to the ON mode.

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

    Test condition	Vehicle ON mode
    	HFL-ANC/active sound control microphone 8P connector: disconnected
    Test circuit	ACC
    Test point 1	HFL-ANC/active sound control microphone 8P connector No. 1 (PUR)
    Test point 2	Body ground

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

    Is there battery voltage?

    YES 

    The ACC wire is OK. Go to step 16.

    NO 

    Repair an open in the wire.

16. Open wire check (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
    	HFL-ANC/active sound control microphone 8P connector: disconnected
    Test circuit	GND
    Test point 1	HFL-ANC/active sound control microphone 8P connector No. 4 (BLK)
    Test point 2	Body ground

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

    Is there continuity?

    YES 

    The GND wire is OK. Go to step 17.

    NO 

    Repair an open in the wire or poor ground (G504).

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

    -1. Turn the vehicle to the ON mode.

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

    Test condition	Vehicle ON mode
    	HFL-ANC/active sound control microphone 8P connector: disconnected
    Test circuit	ANC F MIC+8V
    Test point 1	HFL-ANC/active sound control microphone 8P connector No. 8 (WHT)
    Test point 2	Body ground

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

    Is there about 8.0 V?

    YES 

    Go to step 18.

    NO 

    Go to step 19.

18. Determine possible failure area (HFL-ANC/active sound control microphone, others)

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

    -2. Reconnect the HFL-ANC/active sound control microphone 8P 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 HFL-ANC/active sound control microphone.
    Test circuit	ANC F MIC+8V, SH ANC F MIC
    Test point 1	ANC/active sound control unit 20P connector No. 18 (WHT)
    Test point 2	ANC/active sound control unit 20P connector No. 7 (GRY)

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

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

    YES 

    Replace the ANC/active sound control unit .

    NO 

    Replace the HFL-ANC/active sound control microphone .

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

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

    Test condition	Vehicle ON mode
    	HFL-ANC/active sound control microphone 8P connector: disconnected
    Test circuit	ANC F MIC+8V
    Test point 1	ANC/active sound control unit 20P connector No. 18 (WHT)
    Test point 2	Body ground

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

    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 20.

20. 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
    	HFL-ANC/active sound control microphone 8P connector: disconnected

    	ANC/active sound control unit 20P connector: disconnected
    Test circuit	ANC F MIC+8V
    Test point 1	ANC/active sound control unit 20P connector No. 18 (WHT)
    Test point 2	Body ground

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

    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 21.

21. 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
    	HFL-ANC/active sound control microphone 8P connector: disconnected
    	ANC/active sound control unit 20P connector: disconnected
    Test circuit	SH ANC F MIC, ANC F MIC+8V
    Test point 1	ANC/active sound control unit 20P connector No. 7 (GRY)
    Test point 2	ANC/active sound control unit 20P connector No. 18 (WHT)

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

    Is there continuity?

    YES 

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

    NO 

    Replace the ANC/active sound control unit .

22. Open wire check (IG1 OPTION line)

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

    -2. Disconnect 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
    	ANC/active sound control unit 20P connector: disconnected
    Test circuit	IG1 OPTION
    Test point 1	ANC/active sound control unit 20P connector No. 12 (WHT)
    Test point 2	Body ground

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

    Is there battery voltage?

    YES 

    The IG1 OPTION wire is OK. Go to step 23.

    NO 

    Repair an open in the wire.

23. Shorted wire check (AUD F MIX line, AUD F MIX GND line)

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

    -2. Disconnect the following connector.

    NOTE:  Eject the disc before disconnecting the audio unit to prevent damaging the CD player's load mechanism.

    Audio unit connector A (24P)

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

    Test condition	Vehicle OFF (LOCK) mode
    	ANC/active sound control unit 20P connector: disconnected
    	Audio unit connector A (24P): disconnected
    Test circuit	AUD F MIX
    Test point 1	ANC/active sound control unit 20P connector No. 16 (YEL)
    Test point 2	Body ground

    Test circuit	AUD F MIX GND
    Test point 1	ANC/active sound control unit 20P connector No. 15 (BRN)
    Test point 2	Body ground

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

    Is there continuity?

    YES 

    Repair a short in the wire.

    NO 

    The AUD F MIX and the AUD F MIX GND wires are OK. Go to step 24.

24. Open wire check (F-CAN A_H line, F-CAN A_L line)

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

    -2. Disconnect the following connector.

    CAN gateway 16P connector

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

    Test condition	Vehicle OFF (LOCK) mode
    	Audio unit connector A (24P): disconnected
    	ANC/active sound control unit 20P connector: disconnected
    	CAN gateway 16P connector: disconnected
    Test circuit	F-CAN A_H
    Test point 1	ANC/active sound control unit 20P connector No. 4 (WHT)
    Test point 2	CAN gateway 16P connector No. 3 (WHT)

    Test circuit	F-CAN A_L
    Test point 1	ANC/active sound control unit 20P connector No. 5 (RED)
    Test point 2	CAN gateway 16P connector No. 11 (RED)

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

    Is there continuity?

    YES 

    The F-CAN A_H wire and the F-CAN A_L wire are OK. Go to step 25.

    NO 

    Repair an open in the wire(s).

25. ANC/active sound control unit check

    -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 

    Replace the audio unit .