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Home >> Acura >> 2019 >> MDX Base >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Network Communication - Diagnostics (Except Hybrid) >> Troubleshooting >> DLC Circuit Troubleshooting (2017 2018, With CAN Gateway)

DLC Circuit Troubleshooting (2017 2018, With CAN Gateway)

DLC Circuit Troubleshooting 

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.

    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 10.

  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
         

    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 EPS system, go to step 4.

    NO 

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

    NO 

    If the HDS does not communicate with the BODY ELECTRICAL system, go to step 6.

  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 7.

    NO 

    Go to the symptom troubleshooting for SRS indicator stays on, but no DTCs are stored, or cannot be read - Refer to: SRS Symptom Troubleshooting - SRS indicator stays on, but no DTCs are stored, or cannot be read (2017 2018 2019 2020), .

  4. 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 7.

    NO 

    Go to the EPS symptom troubleshooting for EPS indicator does not go off, and no DTCs are stored - Refer to: or EPS Symptom Troubleshooting - EPS indicator does not go off, and no DTCs are stored (2017 2018), or EPS Symptom Troubleshooting - EPS indicator does not go off, and no DTCs are stored (2017 2018), or EPS Symptom Troubleshooting - EPS indicator does not go off, and no DTCs are stored (2017 2018) .

  5. 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 - Refer to: Keyless Access System Symptom Troubleshooting Information (2016 2017 2018 2019 2020) .

    NO 

    The keyless access system is OK. Go to step 7.

  6. Body electrical system check

    -1. Do the gauge self-diagnostic function.

    - 2. Check the gauge display.

    Is B-CAN------ERROR indicated?

    YES 

    Go to the indicated DTC's troubleshooting.

    NO 

    The body electrical system is OK. Go to step 7.

  7. Open wire check (K-LINE line or P-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 P-LINE that does not communicate.

    K-LINE 

    • ANC/active sound control unit 20P connector
    • EPS control unit connector A (11P)
    • Audio-navigation unit connector A (24P)
    • Keyless access/TPMS control unit connector C (20P)
    • Driver's under-dash fuse/relay box connector G (16P)

    P-LINE 

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

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

    K-LINE 

    Connector Terminal
    ANC/active sound control unit 20P connector No. 14
    EPS control unit connector A (11P) No. 7
    Audio-navigation unit connector A (24P) No. 13
    Keyless access/TPMS control unit connector C (20P) No. 4
    Driver's under-dash fuse/relay box connector G (16P) No. 13

    P-LINE 

    Connector Terminal
    Keyless access/TPMS control unit connector C (20P) No. 6
    SRS unit connector A (39P) No. 33
    GHH324751Courtesy of HONDA, U.S.A., INC.

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

    YES 

    Go to step 8.

    NO 

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

  8. Determine possible failure area (short in K-LINE line or P-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:
    Test point 2 Body ground
    GHH324753Courtesy of HONDA, U.S.A., INC.

    Is there any voltage?

    YES 

    Go to step 10.

    NO 

    Go to step 9.

  9. Shorted wire check (K-LINE line, P-LINE line)

    -1. Continue to measure the voltage between DLC (16P) No. 7 (K-LINE line) and body ground, or DLC (16P) No. 15 (P-LINE line) and body ground 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.

    K-LINE 

    • ANC/active sound control unit 20P connector
    • EPS control unit connector A (11P)
    • Audio-navigation unit connector A (24P)
    • Keyless access/TPMS control unit connector C (20P)
    • Driver's under-dash fuse/relay box connector G (16P)

    P-LINE 

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

    Does continuity go away 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 ANC/active sound control unit, the EPS control unit, the audio-navigation unit, the keyless access/TPMS control unit, the driver's under-dash fuse/relay box (MICU), or DLC (16P) No. 15 (P-LINE) and the keyless access/TPMS control unit or the SRS unit.

  10. Body electrical system (B-CAN) check

    -1. Do the gauge self-diagnostic function.

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

    Is DTC U0029 and/or U0100 indicated?

    YES 

    Do the PCM power and ground circuit troubleshooting - Refer to: PCM Power and Ground Circuit Troubleshooting (2017 2018 2019 2020) .

    NO 

    Go to step 11.

  11. Open wire check (+B BACK UP 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:
    Test point 2 Body ground
    GHH324755Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    The +B BACK UP wire is OK. Go to step 12.

    NO 

    Repair an open in the +B BACK UP wire between DLC (16P) No. 16 and the No. C16 (10 A) fuse in the under-hood fuse/relay box.

  12. 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:
    Test point 2 DLC (16P) (female terminals) No. 16:
    GHH324758Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    The PGND wire is OK. Go to step 13.

    NO 

    Repair an open in the PGND wire between DLC (16P) No. 4 and G501.

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

    -1. Disconnect the following connector.

    PCM connector A (51P)

    - 2. 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 (2017 2018 2019 2020)
    Test point 2 DLC (16P) (female terminals) No. 6:
    GHH324760Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The F-CAN A_H wire is not open. Go to step 14.

    NO 

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

  14. 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 (2017 2018 2019 2020)
    Test point 2 DLC (16P) (female terminals) No. 14:
    GHH324762Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The F-CAN A_L wire is not open. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good PCM - Refer to: PCM Removal and Installation (2016 2017 2018 2019 2020) .

    NO 

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

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