DTC B2456: Left Headlight ECU Variation Error [11/2021 - ]: Procedure

WARNING: This page does not describe the selected car, but rather 18 other vehicles, including the 2024 Lexus IS 500, 2024 Lexus IS 350, 2024 Lexus IS 300, 2023 Lexus IS 500, and 2023 Lexus IS 350. However, it is still accessible from the selected car via links, so may be relevant.

CLEAR DTC

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.
Enter the following menus: Body Electrical / HL AutoLeveling / Trouble Codes.

Clear the DTCs.

Body Electrical > HL AutoLeveling > Clear DTCs

Result

Proceed to
NEXT

Result:

See step 2

CHECK FOR DTC

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.
Enter the following menus: Body Electrical / HL AutoLeveling / Trouble Codes.

Check for DTCs.

Body Electrical > HL AutoLeveling > Trouble Codes

DTC B2456 is not output.

Result

Proceed to
OK
NG

Result:

USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2021 - 09/2022] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [09/2022 - ]

Result:

See step 3

CHECK ECM

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

Part number is correct.

Result

Proceed to
OK
NG

Result:

REPLACE ECM

8AR-FTS: Refer to REMOVAL [08/2015 - ]

2GR-FKS: Refer to REMOVAL [10/2017 - ]

2UR-GSE: Refer to REMOVAL [11/2021 - ]

Result:

See step 4

CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

Check if the part number of the main body ECU (multiplex network body ECU) installed to the vehicle is correct.

Part number is correct.

Result

Proceed to
OK
NG

Result:

REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH. Refer to REMOVAL [09/2020 - ]

Result:

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to REMOVAL [04/2013 - ]