LIGHTING SYSTEM, Diagnostic DTC:B2439, B243A

DTC Code DTC Name
B2439 Headlamp LH Circuit
B243A Headlamp RH Circuit

DESCRIPTION

This DTC is output when the headlight ECU sub-assembly receives an abnormal signal from the headlight unit assembly.

The headlight ECU sub-assembly LH outputs DTC B2439 and B243A.

DTC No. Detection Item DTC Detection Condition Trouble Area
B2439 Headlamp LH Circuit Headlight ECU sub-assembly LH light source malfunction

  • Headlight LED unit assembly LH

  • Headlight unit assembly LH

  • Headlight ECU sub-assembly LH
B243A Headlamp RH Circuit Headlight ECU sub-assembly RH light source malfunction

  • Headlight LED unit assembly RH

  • Headlight unit assembly RH

  • Headlight ECU sub-assembly RH

WIRING DIAGRAM

B006NS2E01

CAUTION / NOTICE / HINT

Note

After the headlight ECU sub-assembly LH is replaced, vehicle information registration and initialization are necessary.

Click here

PROCEDURE


  1. CHECK FOR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > HL AutoLeveling > Clear DTCs

    2. Check for DTCs.

      Click here


      Body Electrical > HL AutoLeveling > Trouble Codes
      OK
      DTC B2439 or B243A output does not occur.
      Result
      Result Proceed to
      OK A
      NG (DTC B2439 is output) B
      NG (DTC B243A is output) C

    A

    USE SIMULATION METHOD TO CHECK Click here

    C

    CHECK HEADLIGHT UNIT ASSEMBLY RH Click here

    B

  2. CHECK HEADLIGHT UNIT ASSEMBLY LH


    1. Interchange the headlight unit assembly LH with RH and connect the connectors to them.

      for ALPHARD:

      Click here

      for VELLFIRE:

      Click here

    2. Clear the DTCs.

      Click here


      Body Electrical > HL AutoLeveling > Clear DTCs

    3. Check for DTCs.

      Click here


      Body Electrical > HL AutoLeveling > Trouble Codes
      Result
      Result Proceed to
      DTC B2439 is output A
      DTC B243A is output B

    A

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here

    B

  3. CHECK HEADLIGHT UNIT ASSEMBLY LH


    1. B006PJJC01
      *a

      Component without harness connected

      (to Headlight ECU Sub-assembly LH)
      *b

      Component without harness connected

      (to Headlight LED Unit Assembly LH)

      Remove the headlight unit assembly LH.

      for ALPHARD:

      Click here

      for VELLFIRE:

      Click here

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

      Standard Resistance
      w/ Cornering Light
      Tester Connection Condition Specified Condition
      B-2 - D-2 Always Below 1 Ω
      B-3 - D-1 Always Below 1 Ω
      w/o Cornering Light
      Tester Connection Condition Specified Condition
      B-4 - D-2 Always Below 1 Ω
      B-3 - D-1 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE HEADLIGHT LED UNIT ASSEMBLY LH for ALPHARD: REPLACE HEADLIGHT LED UNIT ASSEMBLY LH Click here
    REPLACE HEADLIGHT LED UNIT ASSEMBLY LH for VELLFIRE: REPLACE HEADLIGHT LED UNIT ASSEMBLY LH Click here

    NG

    REPLACE HEADLIGHT UNIT ASSEMBLY LH for ALPHARD: REPLACE HEADLIGHT UNIT ASSEMBLY LH Click here
    REPLACE HEADLIGHT UNIT ASSEMBLY LH for VELLFIRE: REPLACE HEADLIGHT UNIT ASSEMBLY LH Click here

  4. CHECK HEADLIGHT UNIT ASSEMBLY RH


    1. Interchange the headlight unit assembly RH with LH and connect the connectors to them.

      for ALPHARD:

      Click here

      for VELLFIRE:

      Click here

    2. Clear the DTCs.

      Click here


      Body Electrical > HL AutoLeveling > Clear DTCs

    3. Check for DTCs.

      Click here


      Body Electrical > HL AutoLeveling > Trouble Codes
      Result
      Result Proceed to
      DTC B243A is output A
      DTC B2439 is output B

    A

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH Click here

    B

  5. CHECK HEADLIGHT UNIT ASSEMBLY RH


    1. B006PJJC01
      *a

      Component without harness connected

      (to Headlight ECU Sub-assembly RH)
      *b

      Component without harness connected

      (to Headlight LED Unit Assembly RH)

      Remove the headlight unit assembly RH.

      for ALPHARD:

      Click here

      for VELLFIRE:

      Click here

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

      Standard Resistance
      w/ Cornering Light
      Tester Connection Condition Specified Condition
      B-2 - D-2 Always Below 1 Ω
      B-3 - D-1 Always Below 1 Ω
      w/o Cornering Light
      Tester Connection Condition Specified Condition
      B-4 - D-2 Always Below 1 Ω
      B-3 - D-1 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE HEADLIGHT LED UNIT ASSEMBLY RH for ALPHARD: REPLACE HEADLIGHT LED UNIT ASSEMBLY RH Click here
    REPLACE HEADLIGHT LED UNIT ASSEMBLY RH for VELLFIRE: REPLACE HEADLIGHT LED UNIT ASSEMBLY RH Click here

    NG

    REPLACE HEADLIGHT UNIT ASSEMBLY RH for ALPHARD: REPLACE HEADLIGHT UNIT ASSEMBLY RH Click here
    REPLACE HEADLIGHT UNIT ASSEMBLY RH for VELLFIRE: REPLACE HEADLIGHT UNIT ASSEMBLY RH Click here