ADAPTIVE HIGH BEAM SYSTEM, Diagnostic DTC:B2440, B2441

DTC Code DTC Name
B2440 Lost Communication with AHS EDU LH Module
B2441 Lost Communication with AHS EDU RH Module

DESCRIPTION

This DTC is output when there is a LIN communication malfunction between the headlight ECU sub-assembly and headlight light control ECU sub-assembly. The headlight ECU sub-assembly LH outputs DTCs B2440 and B2441.

DTC Code DTC Detection Condition Trouble Area
B2440 Headlight light control ECU sub-assembly LH communication malfunction

  • Headlight unit assembly LH

  • Headlight light control ECU sub-assembly LH

  • Headlight ECU sub-assembly LH
B2441 Headlight light control ECU sub-assembly RH communication malfunction

  • Headlight unit assembly RH

  • Headlight light control ECU sub-assembly RH

  • Headlight ECU sub-assembly LH

  • Headlight ECU sub-assembly RH

WIRING DIAGRAM

B001935E01

CAUTION / NOTICE / HINT

Note

If the headlight ECU sub-assembly LH has been replaced, it is necessary to synchronize the vehicle information Click here.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC B2440 and B2441 are not output.
      Result
      Result Proceed to
      OK A
      NG (DTC B2440 is output) B
      NG (DTC B2441 is output) C

    A

    USE SIMULATION METHOD TO CHECK Click here

    C

    CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT ECU SUB-ASSEMBLY RH) Click here

    B

  3. INSPECT HEADLIGHT UNIT ASSEMBLY LH


    1. Remove the headlight assembly LH Click here.

    2. Remove the headlight ECU sub-assembly LH Click here.

    3. Remove the headlight light control ECU sub-assembly LH Click here.

    4. B001A8EE02
      Text in Illustration
      *a

      Component without harness connected

      (Headlight ECU Sub-assembly LH Side Connector)
      *b

      Component without harness connected

      (Headlight Light Control ECU Sub-assembly LH Side Connector)

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      B-10 - K-10 Always Below 1 Ω
      B-1 - K-1 Always Below 1 Ω
      C-13 - K-9 Always Below 1 Ω

    NG

    REPLACE HEADLIGHT UNIT ASSEMBLY LH Click here

    OK

  4. REPLACE HEADLIGHT LIGHT CONTROL ECU SUB-ASSEMBLY LH


    1. Replace the headlight light control ECU sub-assembly LH with a new or known good one Click here.

    2. Check for DTCs Click here.

      OK
      DTC B2440 is not output.

    OK

    END (HEADLIGHT LIGHT CONTROL ECU SUB-ASSEMBLY LH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here

  5. CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT ECU SUB-ASSEMBLY RH)


    1. Disconnect the A64 headlight ECU sub-assembly LH connector.

    2. Disconnect the A65 headlight ECU sub-assembly RH connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A64-20 (LINL) - A65-20 (LINL) Always Below 1 Ω
      A64-20 (LINL) or A65-20 (LINL) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT HEADLIGHT UNIT ASSEMBLY RH


    1. Remove the headlight assembly RH Click here.

    2. Remove the headlight ECU sub-assembly RH Click here.

    3. Remove the headlight light control ECU sub-assembly RH Click here.

    4. B001999E02
      Text in Illustration
      *a

      Component without harness connected

      (Headlight ECU Sub-assembly RH Side Connector)
      *b

      Component without harness connected

      (Headlight Light Control ECU Sub-assembly RH Side Connector)

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      B-10 - K-10 Always Below 1 Ω
      B-1 - K-1 Always Below 1 Ω
      C-13 - K-9 Always Below 1 Ω

    NG

    REPLACE HEADLIGHT UNIT ASSEMBLY RH Click here

    OK

  7. REPLACE HEADLIGHT LIGHT CONTROL ECU SUB-ASSEMBLY RH


    1. Replace the headlight light control ECU sub-assembly RH with a new or known good one Click here.

    2. Check for DTCs Click here.

      OK
      DTC B2441 is not output.

    OK

    END (HEADLIGHT LIGHT CONTROL ECU SUB-ASSEMBLY RH WAS DEFECTIVE)

    NG

  8. REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH


    1. Replace the headlight ECU sub-assembly RH with a new or known good one Click here.

    2. Check for DTCs Click here.

      OK
      DTC B2441 is not output.

    OK

    END (HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here