LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2020 >> ES 300h Luxury >> Repair and Diagnosis >> External Pages >> Different car >> Section 166 (Lighting System (Ext) (Except Hybrid) - Diagnostic Codes (2 Of 2) & Symptom Tests) >> LIGHTING SYSTEM (for Gasoline Model) >> DTC B2439: Headlight LH Circuit; DTC B243A: Headlight RH Circuit [06/2018 - 08/2021] >> Procedure

DTC B2439: Headlight LH Circuit; DTC B243A: Headlight RH Circuit [06/2018 - 08/2021]: Procedure

WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2024 Lexus ES 350, 2024 Lexus ES 250, 2023 Lexus ES 350, 2023 Lexus ES 250, and 2022 Lexus ES 350. However, it is still accessible from the selected car via links, so may be relevant.
  1. CONFIRM MODEL 
    1. Choose the model to be inspected.

      Result

      Result Proceed to
      For LED Type Turn Signal Light A
      For Bulb Type Turn Signal Light B

    Result: 

    B 

    See step  10

    Result: 

    A 

    See step  2

  2. CLEAR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / AFS or AFS (Sub) / Trouble Codes.
    5. Clear the DTCs.

      Body Electrical > AFS > Clear DTCs 

      Body Electrical > AFS (Sub) > Clear DTCs 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  3

  3. CHECK FOR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Operate the light control switch to turn on the low beam headlights and wait 10 seconds or more.
    4. Turn the Techstream on.
    5. Enter the following menus: Body Electrical / AFS or AFS (Sub) / Trouble Codes.
    6. Check for DTCs.

      Body Electrical > AFS > Trouble Codes 

      Body Electrical > AFS (Sub) > Trouble Codes 

      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 [06/2018 - ] 

    Result: 

    C 

    See step  7

    Result: 

    B 

    See step  4

  4. CHECK HEADLIGHT UNIT ASSEMBLY LH 
    1. Interchange the headlight unit assembly LH with RH and connect the connectors.

      Refer to DISASSEMBLY [06/2018 - 08/2021]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  5

  5. CLEAR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / AFS or AFS (Sub) / Trouble Codes.
    5. Clear the DTCs.

      Body Electrical > AFS > Clear DTCs 

      Body Electrical > AFS (Sub) > Clear DTCs 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  6

  6. CHECK FOR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Operate the light control switch to turn on the low beam headlights and wait 10 seconds or more.
    4. Turn the Techstream on.
    5. Enter the following menus: Body Electrical / AFS or AFS (Sub) / Trouble Codes.
    6. Check for DTCs.

      Body Electrical > AFS > Trouble Codes 

      Body Electrical > AFS (Sub) > Trouble Codes 

      Result

      Result Proceed to
      DTC B2439 is output A
      DTC B243A is output B

    Result: 

    A 

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH. Refer to  REMOVAL [06/2018 - 09/2022] 

    Result: 

    B 

    REPLACE HEADLIGHT UNIT ASSEMBLY LH. Refer to  DISASSEMBLY [06/2018 - 08/2021] 

  7. CHECK HEADLIGHT UNIT ASSEMBLY RH 
    1. Interchange the headlight unit assembly RH with LH and connect the connectors.

      Refer to DISASSEMBLY [06/2018 - 08/2021]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  8

  8. CLEAR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / AFS or AFS (Sub) / Trouble Codes.
    5. Clear the DTCs.

      Body Electrical > AFS > Clear DTCs 

      Body Electrical > AFS (Sub) > Clear DTCs 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  9

  9. CHECK FOR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Operate the light control switch to turn on the low beam headlights and wait 10 seconds or more.
    4. Turn the Techstream on.
    5. Enter the following menus: Body Electrical / AFS or AFS (Sub) / Trouble Codes.
    6. Check for DTCs.

      Body Electrical > AFS > Trouble Codes 

      Body Electrical > AFS (Sub) > Trouble Codes 

      Result

      Result Proceed to
      DTC B243A is output A
      DTC B2439 is output B

    Result: 

    A 

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH. Refer to  REMOVAL [06/2018 - 09/2022] 

    Result: 

    B 

    REPLACE HEADLIGHT UNIT ASSEMBLY RH. Refer to  DISASSEMBLY [06/2018 - 08/2021] 

  10. CLEAR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.
    5. Clear the DTCs.

      Body Electrical > HL AutoLeveling > Clear DTCs 

      Body Electrical > HL AutoLeveling (Sub) > Clear DTCs 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  11

  11. CONFIRM MODEL 
    1. Choose the model to be inspected.

      Result

      Result Proceed to
      For TMC Made A
      For TMMK Made B

    Result: 

    B 

    See step  19

    Result: 

    A 

    See step  12

  12. CHECK FOR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Operate the light control switch to turn on the low beam headlights and wait 10 seconds or more.
    4. Turn the Techstream on.
    5. Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.
    6. Check for DTCs.

      Body Electrical > HL AutoLeveling > Trouble Codes 

      Body Electrical > HL AutoLeveling (Sub) > Trouble Codes 

      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 [06/2018 - ] 

    Result: 

    C 

    See step  16

    Result: 

    B 

    See step  13

  13. CHECK HEADLIGHT UNIT ASSEMBLY LH 
    1. Interchange the headlight unit assembly LH with RH and connect the connectors.

      Refer to DISASSEMBLY [06/2018 - 08/2021]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  14

  14. CLEAR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.
    5. Clear the DTCs.

      Body Electrical > HL AutoLeveling > Clear DTCs 

      Body Electrical > HL AutoLeveling (Sub) > Clear DTCs 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  15

  15. CHECK FOR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Operate the light control switch to turn on the low beam headlights and wait 10 seconds or more.
    4. Turn the Techstream on.
    5. Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.
    6. Check for DTCs.

      Body Electrical > HL AutoLeveling > Trouble Codes 

      Body Electrical > HL AutoLeveling (Sub) > Trouble Codes 

      Result

      Result Proceed to
      DTC B2439 is output A
      DTC B243A is output B

    Result: 

    A 

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH. Refer to  REMOVAL [06/2018 - 09/2022] 

    Result: 

    B 

    REPLACE HEADLIGHT UNIT ASSEMBLY LH. Refer to  DISASSEMBLY [06/2018 - 08/2021] 

  16. CHECK HEADLIGHT UNIT ASSEMBLY RH 
    1. Interchange the headlight unit assembly RH with LH and connect the connectors.

      Refer to DISASSEMBLY [06/2018 - 08/2021]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  17

  17. CLEAR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.
    5. Clear the DTCs.

      Body Electrical > HL AutoLeveling > Clear DTCs 

      Body Electrical > HL AutoLeveling (Sub) > Clear DTCs 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  18

  18. CHECK FOR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Operate the light control switch to turn on the low beam headlights and wait 10 seconds or more.
    4. Turn the Techstream on.
    5. Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.
    6. Check for DTCs.

      Body Electrical > HL AutoLeveling > Trouble Codes 

      Body Electrical > HL AutoLeveling (Sub) > Trouble Codes 

      Result

      Result Proceed to
      DTC B243A is output A
      DTC B2439 is output B

    Result: 

    A 

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH. Refer to  REMOVAL [06/2018 - 09/2022] 

    Result: 

    B 

    REPLACE HEADLIGHT UNIT ASSEMBLY RH. Refer to  DISASSEMBLY [06/2018 - 08/2021] 

  19. CHECK FOR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Operate the light control switch to turn on the low beam headlights and wait 10 seconds or more.
    4. Turn the Techstream on.
    5. Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.
    6. Check for DTCs.

      Body Electrical > HL AutoLeveling > Trouble Codes 

      Body Electrical > HL AutoLeveling (Sub) > Trouble Codes 

      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 [06/2018 - ] 

    Result: 

    C 

    See step  23

    Result: 

    B 

    See step  20

  20. CHECK HEADLIGHT ASSEMBLY LH 
    1. Remove each headlight ECU sub-assembly, interchange the headlight assembly LH with RH and connect the connectors.

      Refer to REMOVAL [06/2018 - 08/2021]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  21

  21. CLEAR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.
    5. Clear the DTCs.

      Body Electrical > HL AutoLeveling > Clear DTCs 

      Body Electrical > HL AutoLeveling (Sub) > Clear DTCs 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  22

  22. CHECK FOR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Operate the light control switch to turn on the low beam headlights and wait 10 seconds or more.
    4. Turn the Techstream on.
    5. Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.
    6. Check for DTCs.

      Body Electrical > HL AutoLeveling > Trouble Codes 

      Body Electrical > HL AutoLeveling (Sub) > Trouble Codes 

      Result

      Result Proceed to
      DTC B2439 is output A
      DTC B243A is output B

    Result: 

    A 

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH. Refer to  REMOVAL [06/2018 - 09/2022] 

    Result: 

    B 

    REPLACE HEADLIGHT ASSEMBLY LH. Refer to  REMOVAL [06/2018 - 08/2021] 

  23. CHECK HEADLIGHT ASSEMBLY RH 
    1. Remove each headlight ECU sub-assembly, interchange the headlight assembly RH with LH and connect the connectors.

      Refer to REMOVAL [06/2018 - 08/2021]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  24

  24. CLEAR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.
    5. Clear the DTCs.

      Body Electrical > HL AutoLeveling > Clear DTCs 

      Body Electrical > HL AutoLeveling (Sub) > Clear DTCs 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  25

  25. CHECK FOR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Operate the light control switch to turn on the low beam headlights and wait 10 seconds or more.
    4. Turn the Techstream on.
    5. Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.
    6. Check for DTCs.

      Body Electrical > HL AutoLeveling > Trouble Codes 

      Body Electrical > HL AutoLeveling (Sub) > Trouble Codes 

      Result

      Result Proceed to
      DTC B243A is output A
      DTC B2439 is output B

    Result: 

    A 

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH. Refer to  REMOVAL [06/2018 - 09/2022] 

    Result: 

    B 

    REPLACE HEADLIGHT ASSEMBLY RH. Refer to  REMOVAL [06/2018 - 08/2021] 

scientia non olet · About LEMON Manuals