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 a malfunction in the automatic high beam system.

DTC No. DTC Detection Condition Trouble Area
B124B Malfunction in automatic high beam system

  • Vehicle stability control system

  • CAN communication system

  • Inner rear view mirror assembly

  • Main body ECU (multiplex network body ECU)

INSPECTION PROCEDURE

Note

Confirm that the CAN communication system is not malfunctioning before performing the following inspection Click here.

PROCEDURE


  1. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC B124B is not output.

    NG

    CHECK FOR DTC Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  2. CHECK FOR DTC


    1. Check for DTCs Click here.

      Result
      Result Proceed to
      Other DTCs are not output A
      Vehicle stability control system DTCs are output B
      CAN communication system DTCs are output C

    B

    GO TO VEHICLE STABILITY CONTROL SYSTEM Click here

    C

    GO TO CAN COMMUNICATION SYSTEM Click here

    A

  3. REPLACE INNER REAR VIEW MIRROR ASSEMBLY


    1. Replace the inner rear view mirror assembly with a new or known good one Click here.

    2. Check for DTCs Click here.

      OK
      DTC B124B is not output.

    NG

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    OK

    END (INNER REAR VIEW MIRROR ASSEMBLY WAS DEFECTIVE)