LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Honda >> 2019 >> Clarity Plug-In Hybrid >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Body Control Module - Diagnostics (Plug-In) >> DTC Troubleshooting >> DTC B1038
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC B1038

DTC B1038  : IMMOBILIZER F-CAN Authentication ID Not Received

NOTE:
  • Refer to the DTC shown on the display, then inspect the connectors and terminals based on the instructions.
  • According to the detected DTC(s), check for the power circuit and the ground circuit of the control unit which cannot communicate with the body control module.
DTC Description DTC
B1038 IMMOBILIZER F-CAN Authentication ID Not Received  

DTC (Body Control Module)

  1. CAN gateway system DTC check

    -1. Check for CAN gateway system DTCs with the HDS.

    DTC Description DTC
    U0029-00 CAN Gateway F-CAN ch A Bus Off  
    U0047-00 CAN Gateway F-CAN ch B Bus Off  
    U0056-00 CAN Gateway F-CAN ch C Bus Off  
    U0065-00 CAN Gateway F-CAN ch D Bus Off  
    U3000-49 CAN Gateway Internal Failure  

    DTC (CAN GATEWAY)

    Is DTC U0029-00, U0047-00, U0056-00, U0065-00, and/or U3000-49 indicated?

    YES 

    Go to the troubleshooting for CAN gateway system DTC(s) .

    NO 

    Go to step 2.

  2. F-CAN circuit communication check

    -1. Select the FUNCTION TEST in the CAN gateway with the HDS, then select the F-CAN Bus Connected Unit Check.

    F-CAN Bus Connected Unit Check

    Does the body control module detect the CAN gateway Bus channels B?

    Bus B is Not Available 

    Go to step 3.

    Bus B is Available 

    Go to step 4.

  3. Open wire check (F-CAN B lines)

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

    -2. Disconnect the following connectors.

    CAN gateway 16P connector
    Body control module connector B (36P)

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

    Test condition Vehicle OFF (LOCK) mode
    CAN gateway 16P connector: disconnected
    Body control module connector B (36P): disconnected
    Test point 1 CAN gateway 16P connector (female terminals) No. 6:
    Test point 2 Body control module connector B (36P) No. 22
    Test point 1 CAN gateway 16P connector (female terminals) No. 14:
    Test point 2 Body control module connector B (36P) No. 23
    GHH415272Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The F-CAN B_H and F-CAN B_L wires are OK. Replace the body control module .

    NO 

    Repair an open in F-CAN B_H or F-CAN B_L wire.

  4. F-CAN circuit communication check (Transmitting control unit)

    -1. Select the FUNCTION TEST in the CAN gateway with the HDS, then select the F-CAN Bus Connected Unit Check.

    F-CAN Bus Connected Unit Check

    According to the detected DTC on the following table, make sure that the transmitting control unit detects the CAN gateway Bus channel(s) normally.

    DTC Transmitting control unit Detected CAN gateway Bus channel(s) at normal
    B1038 VSA modulator-control unit B, C

    Is it detected normally?

    Detected normal 

    Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the transmitting control unit and the CAN gateway.

    U1038: VSA modulator-control unit is Not Available for Bus B 

    Go to step 5.

    U1038: VSA modulator-control unit is Not Available for Bus C 

    Go to step 6.

  5. Open wire check (F-CAN B lines)

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

    -2. According to the detected DTC on the following table, disconnect the transmitting control unit connector(s).

    DTC Connector
    - CAN gateway 16P connector
    B1038 VSA modulator-control unit 46P connector

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

    Test condition Vehicle OFF (LOCK) mode
      CAN gateway 16P connector: disconnected
      VSA modulator-control unit 46P connector: disconnected
    DTC Circuit name Test point 1 (Receiving control unit) Test point 2 (Transmitting control unit)
    Connector Terminal Connector Terminal
    B1038 F-CAN B_H CAN gateway 16P connector (female terminals): No. 6 VSA modulator-control unit 46P connector No. 46
    F-CAN B_L No. 14 No. 34
    GHH415274Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The F-CAN B_H wire and the F-CAN B_L wire are OK.

    Refer to the DTC shown on the display, then substitute or replace the control unit based on the instructions (see table).

    DTC Operation for transmitting control unit
    B1038 VSA modulator-control unit

    NO 

    Repair an open in F-CAN B_H or F-CAN B_L wire.

  6. Open wire check (F-CAN C lines)

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

    -2. According to the detected DTC on the following table, disconnect the transmitting control unit connector(s).

    DTC Connector
    - CAN gateway 16P connector
    B1038 VSA modulator-control unit 46P connector

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

    Test condition Vehicle OFF (LOCK) mode
      CAN gateway 16P connector: disconnected
      VSA modulator-control unit 46P connector: disconnected
    DTC Circuit name Test point 1 (Receiving control unit) Test point 2 (Transmitting control unit)
    Connector Terminal Connector Terminal
    B1038 F-CAN C_H CAN gateway 16P connector (female terminals): No. 5 VSA modulator-control unit 46P connector No. 40
    F-CAN C_L No. 13 No. 28
    GHH415276Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The F-CAN C_H wire and the F-CAN C_L wire are OK.

    Refer to the DTC shown on the display, then substitute or replace the control unit based on the instructions (see table).

    DTC Operation for transmitting control unit
    B1038 VSA modulator-control unit

    NO 

    Repair an open in F-CAN C_H or F-CAN C_L wire.

scientia non olet · About LEMON Manuals