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Home >> Lexus >> 2021 >> RX 350 Base, AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Exterior Lights >> Lighting System (W/ Automatic Headlight Beam Level Control System) - Diagnostic Codes >> LIGHTING SYSTEM (w/ Automatic Headlight Beam Level Control System) >> DTC B2439: Headlamp LH Circuit; DTC B243A: Headlamp RH Circuit [09/2015 - 08/2019] >> Procedure
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DTC B2439: Headlamp LH Circuit; DTC B243A: Headlamp RH Circuit [09/2015 - 08/2019]: Procedure

  1. CLEAR DTC 
    1. for Single Beam Headlight without AFS (Adaptive Front-lighting System):
      1. Clear the DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > HL Auto Leveling > Clear DTCs 

    2. for Triple Beam Headlight, for Single Beam Headlight with AFS (Adaptive Front-lighting System):
      1. Clear the DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > AFS > Clear DTCs 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  2

  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. for Single Beam Headlight without AFS (Adaptive Front-lighting System):
      1. Check for DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > HL Auto Leveling > Trouble Codes 

        OK

        DTC B2439 and B243A are not output.

    4. for Triple Beam Headlight, for Single Beam Headlight with AFS (Adaptive Front-lighting System):
      1. Check for DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > AFS > Clear DTCs 

        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

    Result: 

    A 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2015 - 08/2016]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2016 - 12/2017]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2017 - 08/2019] 

    Result: 

    C 

    See step  6

    Result: 

    B 

    See step  3

  3. CHECK HEADLIGHT UNIT LH 
    1. Interchange the headlight unit LH with RH and connect the connectors to them.

      for Single Beam Headlight: Refer to DISASSEMBLY [09/2015 - 08/2019]

      for Triple Beam Headlight: Refer to DISASSEMBLY [09/2015 - 08/2019]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  4

  4. CLEAR DTC 
    1. for Single Beam Headlight without AFS (Adaptive Front-lighting System):
      1. Clear the DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > HL Auto Leveling > Clear DTCs 

    2. for Triple Beam Headlight, for Single Beam Headlight with AFS (Adaptive Front-lighting System):
      1. Clear the DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > AFS > Trouble Codes 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  5

  5. 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. for Single Beam Headlight without AFS (Adaptive Front-lighting System):
      1. Check for DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > HL Auto Leveling > Trouble Codes 

    4. for Triple Beam Headlight, for Single Beam Headlight with AFS (Adaptive Front-lighting System):
      1. Check for DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > AFS > Trouble Codes 

      Result

      Result Proceed to
      DTC B2439 is output A
      DTC B243A is output (for TMC Made) B
      DTC B243A is output (for TMMC Made) C

    Result: 

    A 

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH. Refer to  REMOVAL [09/2015 - 08/2016]  , or refer to  REMOVAL [08/2016 - 08/2019] 

    Result: 

    B 

    REPLACE HEADLIGHT UNIT LH 

    for Single Beam Headlight: Refer to DISASSEMBLY [09/2015 - 08/2019]

    for Triple Beam Headlight: Refer to DISASSEMBLY [09/2015 - 08/2019]

    Result: 

    C 

    REPLACE HEADLIGHT ASSEMBLY LH 

    for Single Beam Headlight: Refer to REMOVAL [09/2015 - 08/2016] , or refer to REMOVAL [08/2016 - 08/2019]

    for Triple Beam Headlight: Refer to REMOVAL [09/2015 - 08/2016] , or refer to REMOVAL [08/2016 - 08/2019]

  6. CHECK HEADLIGHT UNIT RH 
    1. Interchange the headlight unit RH with LH and connect the connectors to them.

      for Single Beam Headlight: Refer to DISASSEMBLY [09/2015 - 08/2019]

      for Triple Beam Headlight: Refer to DISASSEMBLY [09/2015 - 08/2019]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  7

  7. CLEAR DTC 
    1. for Single Beam Headlight without AFS (Adaptive Front-lighting System):
      1. Clear the DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > HL Auto Leveling > Clear DTCs 

    2. for Triple Beam Headlight, for Single Beam Headlight with AFS (Adaptive Front-lighting System):
      1. Clear the DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > AFS > Clear DTCs 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  8

  8. 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. for Single Beam Headlight without AFS (Adaptive Front-lighting System):
      1. Check for DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > HL Auto Leveling > Trouble Codes 

    4. for Triple Beam Headlight, for Single Beam Headlight with AFS (Adaptive Front-lighting System):
      1. Check for DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > AFS > Trouble Codes 

      Result

      Result Proceed to
      DTC B243A is output A
      DTC B2439 is output (for TMC Made) B
      DTC B2439 is output (for TMMC Made) C

    Result: 

    A 

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH. Refer to  REMOVAL [09/2015 - 08/2016]  , or refer to  REMOVAL [08/2016 - 08/2019] 

    Result: 

    B 

    REPLACE HEADLIGHT UNIT RH 

    for Single Beam Headlight: Refer to DISASSEMBLY [09/2015 - 08/2019]

    for Triple Beam Headlight: Refer to DISASSEMBLY [09/2015 - 08/2019]

    Result: 

    C 

    REPLACE HEADLIGHT ASSEMBLY RH 

    for Single Beam Headlight: Refer to REMOVAL [09/2015 - 08/2016] , or refer to REMOVAL [08/2016 - 08/2019]

    for Triple Beam Headlight: Refer to REMOVAL [09/2015 - 08/2016] , or refer to REMOVAL [08/2016 - 08/2019]

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