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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 B2456: Left Headlight ECU Variation Error [08/2020 - ] >> Procedure

DTC B2456: Left Headlight ECU Variation Error [08/2020 - ]: 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: 

    See step  4

    Result: 

    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 / Trouble Codes.
    5. Clear the DTCs.

      Body Electrical > AFS > 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. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / AFS / Trouble Codes.
    5. Check for DTCs.

      Body Electrical > AFS > Trouble Codes 

      OK

      DTC B2456 is not output.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [06/2018 - ] 

    Result: 

    NG 

    See step  6

  4. 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 / Trouble Codes.
    5. Clear the DTCs.

      Body Electrical > HL AutoLeveling > Clear DTCs 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  5

  5. CHECK FOR 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 / Trouble Codes.
    5. Check for DTCs.

      Body Electrical > HL AutoLeveling > Trouble Codes 

      OK

      DTC B2456 is not output.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [06/2018 - ] 

    Result: 

    NG 

    See step  6

  6. CHECK ECM 
    1. Check if the part number of the ECM installed to the vehicle is correct.

      OK

      Part number is correct.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE ECM 

    2GR-FKS: Refer to REMOVAL [10/2019 - 08/2021] , or refer to REMOVAL [08/2021 - 09/2022] , or refer to REMOVAL [09/2022 - ]

    A25A-FKS: Refer to REMOVAL [08/2020 - 08/2021] , or refer to REMOVAL [08/2021 - 09/2022] , or refer to REMOVAL [09/2022 - ]

    Result: 

    OK 

    See step  7

  7. CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) 
    1. Check if the part number of the main body ECU (multiplex network body ECU) installed to the vehicle is correct.

      OK

      Part number is correct.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

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

    Result: 

    NG 

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [06/2018 - 08/2021]  , or refer to  REMOVAL [08/2021 - 09/2022]  , or refer to  REMOVAL [09/2022 - ]