LIGHTING SYSTEM, Diagnostic DTC:B2439, B243A

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

DESCRIPTION

A DTC is stored when the headlight ECU sub-assembly receives a light source malfunction signal from its respective headlight unit. The headlight ECU sub-assembly LH stores DTC B2439 and B243A.

DTC Code DTC Detection Condition Trouble Area
B2439 Headlight ECU sub-assembly LH light source malfunction

  • Headlight unit assembly LH

  • Headlight unit LH

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

  • Headlight unit assembly RH

  • Headlight unit RH

  • Headlight ECU sub-assembly RH

WIRING DIAGRAM

B001891E12
*a LO Beam
*b Headlight Unit
*c Headlight Unit Assembly
*d Headlight ECU Sub-assembly

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. Turn the engine switch on (IG).

    2. Operate the light control switch to turn on the low beam headlights and then turn on the high beam headlights.

    3. Check for DTCs Click here.

      OK
      DTC B2439 and B243A are not output.
      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

    INSPECT HEADLIGHT UNIT ASSEMBLY RH Click here

    B

  3. INSPECT HEADLIGHT UNIT ASSEMBLY LH


    1. Remove the headlight assembly LH Click here.

    2. Remove the headlight unit LH from the headlight assembly LH Click here.

    3. B001ALJE02

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B-4 - G-2 Always Below 1 Ω
      B-3 - G-1 Always Below 1 Ω

    NG

    REPLACE HEADLIGHT UNIT ASSEMBLY LH Click here

    OK

  4. REPLACE HEADLIGHT UNIT LH


    1. Replace the headlight unit LH with a new or known good one Click here.


    NEXT

  5. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  6. CHECK FOR DTC


    1. Turn the engine switch on (IG).

    2. Operate the light control switch to turn on the low beam headlights and then turn on the high beam headlights.

    3. Check for DTCs Click here.

      OK
      DTC B2439 is not output.

    OK

    END (HEADLIGHT UNIT LH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here

  7. INSPECT HEADLIGHT UNIT ASSEMBLY RH


    1. Remove the headlight assembly RH Click here.

    2. Remove the headlight unit RH from the headlight assembly RH Click here.

    3. B001ALJE02

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B-4 - G-2 Always Below 1 Ω
      B-3 - G-1 Always Below 1 Ω

    NG

    REPLACE HEADLIGHT UNIT ASSEMBLY RH Click here

    OK

  8. REPLACE HEADLIGHT UNIT RH


    1. Replace the headlight unit RH with a new or known good one Click here.


    NEXT

  9. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  10. CHECK FOR DTC


    1. Turn the engine switch on (IG).

    2. Operate the light control switch to turn on the low beam headlights and then turn on the high beam headlights.

    3. Check for DTCs Click here.

      OK
      DTC B243A is not output.

    OK

    END (HEADLIGHT UNIT RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH Click here