LIGHTING SYSTEM, Diagnostic DTC:B2430, B2431

DTC Code DTC Name
B2430 LED Headlight LH Circuit Malfunction
B2431 LED Headlight RH Circuit Malfunction

DESCRIPTION

The illumination of the low beam headlights is controlled by the instrument panel junction block (main body ECU). When the headlights are turned on, the headlight leveling ECU receives a signal from the headlight light control ECU and detects the illumination condition of the low beam headlights.

DTC Code DTC Detection Condition Trouble Area
B2430 LED headlight LH circuit malfunction

  • Headlight light control ECU sub-assembly LH

  • Headlight assembly LH

  • Headlight leveling ECU assembly

  • Instrument panel junction block (main body ECU)

  • Instrument panel relay block

  • Harness or connector
B2431 LED headlight RH circuit malfunction

  • Headlight light control ECU sub-assembly RH

  • Headlight assembly RH

  • Headlight leveling ECU assembly

  • Instrument panel junction block (main body ECU)

  • Instrument panel relay block

  • Harness or connector

Tech Tips

DTC B2430 and B2431 are not output if 12 seconds have not elapsed since the ignition switch was turned to ON.

WIRING DIAGRAM

A01BHRCE01

INSPECTION PROCEDURE

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Tech Tips

After replacing the headlight leveling ECU, initialization of the ECU is necessary Click here.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC B2430 or B2431 output does not occur.

    NG

    INSPECT INSTRUMENT PANEL RELAY BLOCK Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  3. INSPECT INSTRUMENT PANEL RELAY BLOCK


    1. A01BHJTE01

      Remove the instrument panel relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      12A-1 - 12B-9 Battery voltage not applied between terminals 12A-1 and 12B-10 10 kΩ or higher
      Battery voltage applied between terminals 12A-1 and 12B-10 Below 1 Ω
      12A-1 - 12D-3 Battery voltage not applied between terminals 12A-1 and 12D-4 10 kΩ or higher
      Battery voltage applied between terminals 12A-1 and 12D-4 Below 1 Ω

    NG

    REPLACE INSTRUMENT PANEL RELAY BLOCK

    OK

  4. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL RELAY BLOCK - INSTRUMENT PANEL JUNCTION BLOCK [BODY ECU] AND BATTERY)


    1. Disconnect the 12A, 12B and 12D instrument panel relay block connectors.

    2. Disconnect the 13E instrument panel junction block (main body ECU) connector.

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      12A-1 - Body ground Always 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      12B-10 - 13E-20 (HRLY) Always Below 1 Ω
      12D-4 - 13E-20 (HRLY)
      12B-10 - Body ground Always 10 kΩ or higher
      12D-4 - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL RELAY BLOCK - HEADLIGHT ASSEMBLY)


    1. Disconnect the 12B and 12D instrument panel relay block connectors.

    2. Disconnect the A36*1 and A33*2 headlight connectors.


      • *1: for LH

      • *2: for RH

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

      Standard Resistance
      for LH
      Tester Connection Condition Specified Condition
      12B-9 - A36-6 (LO) Always Below 1 Ω
      12B-9 - Body ground Always 10 kΩ or higher
      for RH
      Tester Connection Condition Specified Condition
      12D-3 - A33-6 (LO) Always Below 1 Ω
      12D-3 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - HEADLIGHT LEVELING ECU ASSEMBLY AND BODY GROUND)


    1. Disconnect the A39 headlight leveling ECU connector.

    2. Disconnect the A36*1 and A33*2 headlight connectors.


      • *1: for LH

      • *2: for RH

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

      Standard Resistance
      for LH
      Tester Connection Condition Specified Condition
      A36-5 (S) - A39-3 (LLEW) Always Below 1 Ω
      A36-4 (E) - Body ground
      A36-5 (S) - Body ground Always 10 kΩ or higher
      for RH
      Tester Connection Condition Specified Condition
      A33-5 (S) - A39-2 (RLEW) Always Below 1 Ω
      A33-4 (E) - Body ground
      A33-5 (S) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. INSPECT HEADLIGHT ASSEMBLY


    1. A01BGI6E01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Headlight Light Control ECU Sub-assembly)
      *b

      Component without harness connected

      (Headlight Assembly)

      Remove the headlight Click here.

    2. Disconnect the headlight light control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      6 (LO) - A-1 Always Below 1 Ω
      5 (S) - A-7
      4 (E) - A-3

    NG

    REPLACE HEADLIGHT ASSEMBLY Click here

    OK

  8. CHECK HEADLIGHT LIGHT CONTROL ECU SUB-ASSEMBLY


    1. Temporarily replace the headlight light control ECU with a new or normally functioning one.

      for LHD: Click here

      for RHD: Click here

    2. Check for DTCs Click here.

      OK
      DTC B2430 or B2431 output does not occur.

    NG

    CHECK HEADLIGHT ASSEMBLY (LED UNIT) Click here

    OK

    END (HEADLIGHT LIGHT CONTROL ECU SUB-ASSEMBLY WAS DEFECTIVE)

  9. CHECK HEADLIGHT ASSEMBLY (LED UNIT)


    1. Temporarily replace the headlight (LED unit) with a new or normally functioning one Click here.

    2. Check for DTCs Click here.

      OK
      DTC B2430 or B2431 output does not occur.

    NG

    CHECK HEADLIGHT LEVELING ECU ASSEMBLY Click here

    OK

    END (HEADLIGHT ASSEMBLY [LED UNIT] WAS DEFECTIVE)

  10. CHECK HEADLIGHT LEVELING ECU ASSEMBLY


    1. Temporarily replace the headlight leveling ECU with a new or normally functioning one.

      for LHD: Click here

      for RHD: Click here

    2. Check for DTCs Click here.

      OK
      DTC B2430 or B2431 output does not occur.

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK (MAIN BODY ECU)

    OK

    END (HEADLIGHT LEVELING ECU ASSEMBLY WAS DEFECTIVE)