AUTOMATIC HIGH BEAM SYSTEM, Diagnostic DTC:B124B

DTC Code DTC Name
B124B Automatic High Beam System

DESCRIPTION

This DTC is stored when the main body ECU (multiplex network body ECU) detects malfunction in the automatic high beam system.

When DTCs for the following systems are stored, this DTC is stored simultaneously.

  • Lane departure alert system malfunction

  • CAN communication system malfunction

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B124B

Automatic High Beam System

Malfunction in automatic high beam system

  • Lane departure alert system

  • CAN communication system

  • Main body ECU (multiplex network body ECU)

WIRING DIAGRAM

  1. E270527E01

CAUTION / NOTICE / HINT

Note:

  • First perform the communication function inspections in How to Proceed with Troubleshooting to confirm that there are no CAN communication malfunctions before troubleshooting this DTC.

  • When the lane departure warning camera is replaced with a new one, adjustment of the lane departure warning camera beam axis must be performed.

    Click hereClick here

  • When replacing the main body ECU (multiplex network body ECU), make sure to replace it with a new one.

PROCEDURE

  1. CHECK FOR DTC (AUTOMATIC HIGH BEAM SYSTEM)

    1. Clear the DTCs.

      Click here

      Body Electrical > Main Body > Clear DTCs

    2. Check for DTCs.

      Click here

      Body Electrical > Main Body > Trouble Codes

    Result

    Proceed to

    DTC B124B is not output

    DTC B124B is output
    DTC B124B is not output

    USE SIMULATION METHOD TO CHECK

    Click hereClick hereClick hereClick here

    DTC B124B is output

  2. CHECK FOR DTC (ALL)

    1. Connect the GTS to DLC3.

    2. Turn the ignition switch to ON.

    3. Enter the following menus: System Select / Health Check.

    4. Check for DTCs.

    Result

    Proceed to

    Lane departure alert system DTCs are not output

    Lane departure alert system DTCs are output

    CAN communication system DTCs are output
    Lane departure alert system DTCs are output

    GO TO LANE DEPARTURE ALERT SYSTEM

    Click here

    CAN communication system DTCs are output

    GO TO CAN COMMUNICATION SYSTEM

    Click here

    Lane departure alert system DTCs are not output

  3. CHECK LANE DEPARTURE WARNING CAMERA

    1. Temporarily replace the lane departure warning camera with a new or normally functioning one.

      Click hereClick here

    2. Check for DTCs.

      Click here

      Body Electrical > Main Body > Trouble Codes

    Result

    Proceed to

    DTC B124B is not output

    DTC B124B is output
    DTC B124B is not output

    END (LANE DEPARTURE WARNING CAMERA WAS DEFECTIVE)

    DTC B124B is output

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

    Click here