DLC Circuit Troubleshooting (2016 2017 2018)

NOTE:  If you suspect the HDS or the HDS DLC cable may be the source of the communication problem, verify that they are working properly by connecting them to a known-good, similar vehicle and system, and checking for communication problems.

1. HDS communication check

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

   - 2. Connect the HDS to the DLC. How to Connect the HDS

   NOTE:  Make sure the HDS is properly connected to the DLC.

   - 3. Turn the vehicle to the ON mode, and turn on the HDS.

   Does the HDS identify the vehicle?

   YES 

   Go to step 2.

   NO 

   Go to step 14.

2. Determine possible failure area (PGM-FI system, other systems)

   -1. Check for Pending or Confirmed DTCs in the PGM-FI system with the HDS.

   DTC Description	Confirmed DTC	Pending DTC	Freeze Frame

   Are any Pending or Confirmed DTCs indicated?

   YES 

   Go to the indicated DTC's troubleshooting.

   NO 

   If the HDS does not communicate with the SRS, go to step 3.

   NO 

   If the HDS does not communicate with the VSA system, go to step 4.

   NO 

   If the HDS does not communicate with the EPS system, go to step 5.

   NO 

   If the HDS does not communicate with the IMMOBI (immobilizer) system, go to step 6.

   NO 

   If the HDS does not communicate with the ONE PUSH START system, go to step 7.

   NO 

   If the HDS does not communicate with the BODY ELECTRICAL system, go to step 8.

   NO 

   If the HDS does not communicate with the DRIVING SUPPORT system, go to step 9.

   NO 

   If the HDS does not communicate with the VTM 4 system, go to step 10.

3. SRS check

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

   - 2. Turn the vehicle to the ON mode, and watch the SRS indicator.

   Does the SRS indicator come on and go off?

   YES 

   The SRS is OK. Go to step 11.

   NO 

   Go to the symptom troubleshooting for SRS indicator stays on, but no DTCs are stored, or cannot be read - Refer to:

   SRS indicator stays on, but no DTCs are stored, or cannot be read (2016) or

   SRS Symptom Troubleshooting - SRS indicator stays on, but no DTCs are stored, or cannot be read (2017 2018 2019 2020 2021) .

4. VSA system check

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

   - 2. Turn the vehicle to the ON mode, and watch the VSA indicator.

   Does the VSA indicator come on and go off?

   YES 

   The VSA system is OK. Go to step 11.

   NO 

   Go to the VSA System Symptom Troubleshooting for:

   ABS Indicator, Brake System Indicator (Red), VSA Indicator, And Brake System Indicator (Amber) Do Not Go OFF [With Auto Idle Stop System] (2016 2017 2018) .

5. EPS system check

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

   - 2. Start the engine, and watch the EPS indicator.

   Does the EPS indicator come on and go off?

   YES 

   The EPS system is OK. Go to step 11.

   NO 

   Go to the EPS Symptom Troubleshooting for: EPS Indicator Does Not Go Off (2016 2017 2018) [With Auto Idle Stop System] and no DTCs are stored.

6. Immobilizer system check

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

   - 2. Turn the vehicle to the ON mode, and watch the immobilizer indicator.

   Does the immobilizer indicator stay on or flash?

   YES 

   Go to the immobilizer system troubleshooting - Go to: Keyless Access System Symptom Troubleshooting Information (2016 2017 2018) .

   NO 

   The immobilizer system is OK. Go to step 11.

7. Keyless access system check

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

   - 2. Turn the vehicle to the ON mode, and watch the keyless access indicator and the immobilizer indicator.

   Does the keyless access indicator stay on or the immobilizer indicator stay on or flash?

   YES 

   Go to the Keyless Access System Symptom Troubleshooting Information .

   NO 

   The keyless access system is OK. Go to step 11.

8. Body electrical system check

   -1. Do the gauge self-diagnostic function.

   Gauges Control Module Self-Diagnostic Function (2016 2017 2018) or

   Gauges Control Module Self-Diagnostic Function (2019 2020 2021) .

   - 2. Check the gauge display.

   Is Error 2 indicated?

   YES 

   Go to the indicated DTC's troubleshooting.

   NO 

   The body electrical system is OK. Go to step 11.

9. Driving support system check

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

   - 2. Turn the vehicle to the ON mode, and watch the ACC indicator, the CMBS/FCW indicator, the LKAS indicator, the RDM/LDW indicator, and/or the BSI indicator.

   Does the ACC indicator, the CMBS/FCW indicator, the LKAS indicator, the RDM/LDW indicator, and/or the BSI indicator come on and go off?

   YES 

   The driving support system is OK. Go to step 11.

   NO 

   • ACC : Indicator does not go off. Refer to:

     ACC Indicator Does Not Go OFF (WITH Auto Idle Stop System) (2016 2017 2018)

     ACC Indicator Does Not Go OFF (WITHOUT Auto Idle Stop System) (2016 2017 2018)

   • CMBS : Indicator does not go off - Go to: Collision Mitigation Braking System (CMBS) Symptom Troubleshooting - CMBS indicator does not go off, .
   • FCW : Indicator does not go off - Go to: Collision Mitigation Braking System (CMBS) Symptom Troubleshooting - FCW indicator does not go off .
   • LKAS: Indicator does not go off. Go to:LKAS Activation Indicator (ON THE MID) Does Not Go OFF .
   • RDM : Indicator does not go off - Refer to:

     Road Departure Mitigation - RDM Indicator Does Not Go OFF (WITH Auto Idle Stop System) (2016 2017 2018)

     Road Departure Mitigation - RDM indicator does not go OFF (WITHOUT Auto Idle Stop System) (2016 2017 2018)

   • LDW : Indicator does not go off - Go to: or Road Departure Mitigation - LDW indicator does not go OFF .
   • BSI : Indicator does not go off. - Go to: Blind Spot Information System/Cross Traffic Monitor - The BSI indicator does not go OFF, or does not come ON .
10. VTM 4 system check

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

    - 2. Turn the vehicle to the ON mode, and watch the AWD indicator.

    Does the AWD indicator come on and go off?

    YES 

    The VTM 4 system is OK. Go to step 11.

    NO 

    Go to the i-VTM System Symptom Troubleshooting - AWD indicator does not go off, and no DTCs are stored .

11. Open wire check (K-LINE line or L-LINE line)

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

    - 2. Disconnect the HDS from the DLC.

    - 3. Disconnect the control unit(s) on the K-LINE or L-LINE that does not communicate.

    NOTE:  Before disconnecting the SRS unit connector, do the 12 Volt Battery Terminal Disconnection procedure, and wait for at least 3 minutes.

    K-LINE 

    • VSA modulator-control unit 38P connector
    • Audio-navigation unit connector A (24P) (with navigation)
    • Audio unit connector A (24P) (with display audio)
    • Audio unit connector A (24P) (with color audio)
    • ANC/active sound control unit 20P connector
    • Keyless access/TPMS control unit connector C (20P)
    • Front passenger's weight sensor unit A (6P) (2016)
    • Under-dash fuse/relay box connector R (16P)

    L-LINE 

    • Keyless access/TPMS control unit connector C (20P)
    • SRS unit connector A (39P)

    - 4. Check for continuity between DLC (16P) No. 7 and these connector terminals (K-LINE line), or DLC (16P) No. 15 and these connector terminals (L-LINE line):

    K-LINE 

    Connector	Terminal
    VSA modulator-control unit 38P connector	No. 33
    Audio-navigation unit connector A (24P) (with navigation)	No. 13
    Audio unit connector A (24P) (with display audio)	No. 13
    Audio unit connector A (24P) (with color audio)	No. 13
    ANC/active sound control unit 20P connector	No. 14
    Keyless access/TPMS control unit connector C (20P)	No. 4
    Front passenger's weight sensor unit A (6P) (2016)	No. 2
    Under-dash fuse/relay box connector R (16P)	No. 9

    L-LINE 

    Connector	Terminal
    Keyless access/TPMS control unit connector C (20P)	No. 6
    SRS unit connector A (39P)	No. 19 (2016), No. 33 (2017 2018)

    Is there continuity between the DLC and the terminals in the chart?

    YES 

    Go to step 12.

    NO 

    Repair an open in the wire between the DLC (K-LINE wire or L-LINE wire) and the appropriate connector.

12. Determine possible failure area (short in K-LINE line or L-LINE line, others)

    -1. Reconnect all connectors.

    - 2. Turn the vehicle to the ON mode.

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

    Test condition	Vehicle ON mode
    Test point 1	DLC (16P) (female terminals) No. 7 and No. 15: (1)
    Test point 2	Body ground

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

    Is there any voltage?

    YES 

    Go to step 14.

    NO 

    Go to step 13.

13. Shorted wire check (K-LINE line, L-LINE line)

    -1. Continue to measure the voltage between DLC (16P) No. 7 and body ground (K-LINE line), or DLC (16P) No. 15 and body ground (L-LINE line) while disconnecting these parts, one at a time:

    NOTE: 

    • Turn the vehicle to the OFF (LOCK) mode before disconnecting the connector, and turn the vehicle to the ON mode before measuring the voltage.
    • Before disconnecting the SRS unit connector, do the 12 Volt Battery Terminal Disconnection procedure, and wait for at least 3 minutes.

    K-LINE 

    • VSA modulator-control unit 38P connector
    • Audio-navigation unit connector A (24P) (with navigation)
    • Audio unit connector A (24P) (with display audio)
    • Audio unit connector A (24P) (with color audio)
    • ANC/active sound control unit 20P connector
    • Keyless access/TPMS control unit connector C (20P)
    • Front passenger's weight sensor unit A (6P) (2016)
    • Under-dash fuse/relay box connector R (16P)

    L-LINE 

    • Keyless access/TPMS control unit connector C (20P)
    • SRS unit connector A (39P)

    Does voltage come back when one of the above components is disconnected?

    YES 

    Replace the part that any voltage was detected when it was disconnected.

    NO 

    Repair a short in the wire between DLC (16P) No. 7 (K-LINE) and the VSA modulator-control unit, the audio-navigation unit, the audio unit, the ANC/active sound control unit, the keyless access/TPMS control unit, the front passenger's weight sensor unit (2016), or the under-dash fuse/relay box (MICU), or DLC (16P) No. 15 (L-LINE) and the keyless access/TPMS control unit or the SRS unit.

14. Body electrical system (B-CAN) check

    -1. Do the gauge self-diagnostic function.

    Gauges Control Module Self-Diagnostic Function (2016 2017 2018) or

    Gauges Control Module Self-Diagnostic Function (2019 2020 2021) .

    - 2. Check for gauge control module DTCs without the HDS.

    Is DTC U0029 and/or U0100 indicated?

    YES 

    Go to the PCM power and ground circuit troubleshooting - Go to: PCM Power and Ground Circuit Troubleshooting (6-Speed A/T, '16-'18 9-Speed A/T) .

    NO 

    Go to step 15.

15. Open wire check (+B BACKUP line)

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

    - 2. Disconnect the HDS from the DLC.

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

    Test condition	Vehicle OFF (LOCK) mode
    Test point 1	DLC (16P) (female terminals) No. 16: (1)
    Test point 2	Body ground

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

    Is there battery voltage?

    YES 

    The +B BACKUP wire is OK. Go to step 16.

    NO 

    Repair an open in the +B BACKUP wire between DLC (16P) No. 16 and the No. A26 (10 A) fuse in the under-hood fuse/relay box.

16. Open wire check (PGND line)

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

    Test condition	Vehicle OFF (LOCK) mode
    Test point 1	DLC (16P) (female terminals) No. 4: (1)
    Test point 2	DLC (16P) (female terminals) No. 16: (1)

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

    Is there battery voltage?

    YES (6-Speed automatic transmission)

    The PGND wire is OK. Go to step 17.

    YES (9-Speed automatic transmission)

    The PGND wire is OK. Go to step 19.

    NO 

    Repair an open in the PGND wire between DLC (16P) No. 4 and G402.

17. Open wire check (F-CAN_H line)

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

    SCS short

    - 2. Disconnect the following connector.

    PCM connector A (51P)

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

    Test condition	Vehicle OFF (LOCK) mode
    	PCM connector A (51P): disconnected
    Test point 1	PCM connector A (51P) No. 9 - Refer to: PCM Connector for Inputs and Outputs (6-Speed A/T) (2016 2017 2018 2019 2020) or PCM Connector for Inputs and Outputs (9-Speed A/T) (2016 2017 2018) .
    Test point 2	DLC (16P) (female terminals) No. 6: (1)

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

    Is there continuity?

    YES 

    The F-CAN_H wire is not open. Go to step 18.

    NO 

    Repair an open in the F-CAN_H wire between the PCM (A9) and DLC (16P) No. 6.

18. Open wire check (F-CAN_L line)

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

    Test condition	Vehicle OFF (LOCK) mode
    	PCM connector A (51P): disconnected
    Test point 1	PCM connector A (51P) No. 10 - Refer to: PCM Connector for Inputs and Outputs (6-Speed A/T) (2016 2017 2018 2019 2020) or PCM Connector for Inputs and Outputs (9-Speed A/T) (2016 2017 2018) .
    Test point 2	DLC (16P) (female terminals) No. 14: (1)

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

    Is there continuity?

    YES 

    The F-CAN_L wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good PCM - Go to: PCM (6-Speed A/T), ('16-'18 9-Speed A/T) - Removal and Installation .

    NO 

    Repair an open in the F-CAN_L wire between the PCM (A10) and DLC (16P) No. 14.

19. Open wire check (F-CAN A_H line)

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

    SCS Short

    - 2. Disconnect the following connector.

    PCM connector A (51P)

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

    Test condition	Vehicle OFF (LOCK) mode
    	PCM connector A (51P): disconnected
    Test point 1	PCM connector A (51P) No. 9 - Refer to: PCM Connector for Inputs and Outputs (6-Speed A/T) (2016 2017 2018 2019 2020) or PCM Connector for Inputs and Outputs (9-Speed A/T) (2016 2017 2018) .
    Test point 2	DLC (16P) (female terminals) No. 6: (1)

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

    Is there continuity?

    YES 

    The F-CAN A_H wire is not open. Go to step 20.

    NO 

    Repair an open in the F-CAN A_H wire between the PCM (A9) and DLC (16P) No. 6.

20. Open wire check (F-CAN A_L line)

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

    Test condition	Vehicle OFF (LOCK) mode
    	PCM connector A (51P): disconnected
    Test point 1	PCM connector A (51P) No. 10 - Refer to: PCM Connector for Inputs and Outputs (6-Speed A/T) (2016 2017 2018 2019 2020) or PCM Connector for Inputs and Outputs (9-Speed A/T) (2016 2017 2018) .
    Test point 2	DLC (16P) (female terminals) No. 14: (1)

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

    Is there continuity?

    YES 

    The F-CAN A_L wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good PCM - Go to:PCM (6-Speed A/T), ('16-'18 9-Speed A/T) - Removal and Installation .

    NO 

    Repair an open in the F-CAN A_L wire between the PCM (A10) and DLC (16P) No. 14.