AUTOMATIC HIGH BEAM SYSTEM, Diagnostic DTC:B124B

DTC Code DTC Name
B124B Automatic High Beam System

DESCRIPTION

The main body ECU (multiplex network body ECU) determines the status of the automatic high beam system based on the automatic high beam system signal from the forward recognition camera.

DTC Code DTC Detection Condition Trouble Area
B124B Malfunction in automatic high beam system

  • CAN communication system

  • Main body ECU (multiplex network body ECU)

  • Forward recognition camera

  • Pre-crash safety system

  • Lane departure alert system

  • SFI system

  • Vehicle stability control system

WIRING DIAGRAM

B0018NNE05
w/o Pre-crash Safety System
*1 Inner Rear View Mirror Assembly
*2 Main Body ECU (Multiplex Network Body ECU)
*3 CAN Communication Line
B0018NNE06
w/ Pre-crash Safety System
*1 Forward Recognition Camera
*2 Main Body ECU (Multiplex Network Body ECU)
*3 CAN Communication Line

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 symptom Click here.

Tech Tips


  • w/ Pre-crash Safety System

    This DTC is output simultaneously from the forward recognition camera when DTCs related to the items below are output.


    • Wheel speed sensor malfunction

    • Yaw rate sensor malfunction

    • Steering angle sensor system malfunction

    • CAN communication lost

PROCEDURE


  1. CHECK FOR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

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

    5. Check for DTCs.

      Result
      Result Proceed to
      Only DTC B124B is output (w/ Pre-crash Safety System) A
      Only DTC B124B is output (w/o Pre-crash Safety System) B
      DTC B124B is output at the same time C

    B

    REPLACE INNER REAR VIEW MIRROR ASSEMBLY Click here

    C

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

    A

  2. CHECK FORWARD RECOGNITION CAMERA


    1. Check if a dynamic radar cruise control system, lane departure alert system and pre-crash safety system warning message is displayed on the combination meter assembly Click here.

      OK
      No dynamic radar cruise control system, lane departure alert system and pre-crash safety system warning messages are displayed.
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

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

    B

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

    C

    GO TO FORWARD RECOGNITION CAMERA SYSTEM Click here