LIGHTING SYSTEM, Diagnostic DTC:B243B, B243C

DTC Code DTC Name
B243B LED Wiring for High Beam LH Circuit
B243C LED Wiring for High Beam RH Circuit

DESCRIPTION

The AFS ECU assembly outputs high beam operation signals to the headlight shade ECU. The headlight light control ECU (for LO/HI beam) operates the high beam LED when it receives a high beam operation signal from the headlight shade ECU.

DTC Code DTC Detection Condition Trouble Area
B243B LH high beam LED output line malfunction

  • Headlight assembly LH

  • Headlight shade ECU

  • Headlight light control ECU sub-assembly (for LO/HI Beam)

  • AFS ECU

  • Harness or connector
B243C RH high beam LED output line malfunction

  • Headlight assembly RH

  • Headlight shade ECU

  • Headlight light control ECU sub-assembly (for LO/HI Beam)

  • AFS ECU

  • Harness or connector

WIRING DIAGRAM

A01H274E01

INSPECTION PROCEDURE

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTC Click here.


    NEXT

  2. CHECK FOR DTC


    1. Turn on the high beam headlight by operating the headlight dimmer switch.

    2. Check for DTC Click here.

      OK
      DTC B243B or B243C output does not occur

    NG

    INSPECT HEADLIGHT ASSEMBLY Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  3. INSPECT HEADLIGHT ASSEMBLY


    1. A01H12KE01

      Remove the headlight Click here.

    2. Disconnect the headlight shade ECU connector Click here.

    3. Disconnect the headlight light control ECU (for LO/HI beam) connector Click here.

    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A-5 (AO) - 10(AI) Always Below 1 Ω
      A-4 (LF) - 5(AO) Always Below 1 Ω

    NG

    REPLACE HEADLIGHT ASSEMBLY Click here

    OK

  4. CHECK HEADLIGHT LIGHT CONTROL ECU SUB-ASSEMBLY (FOR LO/HI BEAM)


    1. Temporarily replace the headlight light control ECU (for LO/HI beam) with a new or normally functioning one Click here.

    2. Turn on the high beam headlight by operating the headlight dimmer switch.

    3. Check for DTC Click here.

      OK
      DTC B243B or B243C output does not occur

    NG

    CHECK HEADLIGHT SHADE ECU Click here

    OK

    END (HEADLIGHT LIGHT CONTROL ECU [FOR LO/HI BEAM] WAS DEFECTIVE)

  5. CHECK HEADLIGHT SHADE ECU


    1. Temporarily replace the headlight shade ECU with a new or normally functioning one Click here.

    2. Turn on the high beam headlight by operating the headlight dimmer switch.

    3. Check for DTC Click here.

      OK
      DTC B243B or B243C output does not occur

    NG

    REPLACE AFS ECU Click here

    OK

    END (HEADLIGHT SHADE ECU WAS DEFECTIVE)