LIGHTING SYSTEM, Diagnostic DTC:B2430, B2431

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

DESCRIPTION

The illumination of the low beam headlights is controlled by the body ECU. When the headlights are turned on, the headlight leveling ECU assembly receives a signal from the headlight assembly and detects the illumination condition of the low beam headlights.

DTC No. Detection Item DTC Detection Condition Trouble Area
B2430 LED Headlight LH Low beam headlight LH malfunction

  • Headlight assembly LH

  • Headlight leveling ECU assembly

  • Body ECU

  • Instrument panel junction block assembly

  • Headlight relay (H-LP)

  • Harness or connector
B2431 LED Headlight RH Low beam headlight RH malfunction

  • Headlight assembly RH

  • Headlight leveling ECU assembly

  • Body ECU

  • Instrument panel junction block assembly

  • Headlight relay (H-LP)

  • 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

B003OY6E03

CAUTION / NOTICE / HINT

Note


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

  • If the headlight leveling ECU assembly has been replaced, it is necessary to initialize the headlight leveling ECU assembly.

    Click here

  • When replacing the headlight leveling ECU assembly, be sure to initialize the automatic light control system.

    Click here

Tech Tips

If DTC B2416 and/or B241A (Automatic Headlight Beam Level Control System) is output at the same time as DTC B2430 and/or B2431, perform troubleshooting for DTC B2416 and/or B241A (Automatic Headlight Beam Level Control System) first.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > HL AutoLeveling > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs.

      Click here


      Body Electrical > HL AutoLeveling > Trouble Codes
      Result
      Result Proceed to
      DTC B2430 and B2431 are not output. A
      DTC B2430 and B2431 are output. B
      DTC B2430 or B2431 is output. C

    A

    USE SIMULATION METHOD TO CHECK Click here

    C

    CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP] - HEADLIGHT ASSEMBLY) Click here

    B

  3. INSPECT HEADLIGHT RELAY (H-LP)


    1. B003S2XN01

      Remove the headlight relay (H-LP) from the engine room relay block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 Battery voltage not applied between terminals 1 and 2 10 kΩ or higher
      3 - 5 Battery voltage applied between terminals 1 and 2 Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEADLIGHT RELAY (H-LP)

    OK

  4. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP] - BATTERY)


    1. B003P9DC01
      *a

      Front view of wire harness connector

      (to Headlight Relay [H-LP])

      Remove the headlight relay (H-LP) from the engine room relay block assembly.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Headlight relay (H-LP) terminal 3 - Body ground Always 11 to 14 V
      Headlight relay (H-LP) terminal 1 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP] - HEADLIGHT ASSEMBLY)


    1. Remove the headlight relay (H-LP) from the engine room relay block assembly.

    2. Disconnect the A57*1 or A56*2 headlight assembly connector.


      • *1: for LH Side

      • *2: for RH Side

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Headlight relay (H-LP) terminal 5 - A57-3 (LO)*1 Always Below 1 Ω
      Headlight relay (H-LP) terminal 5 - A56-3 (LO)*2 Always Below 1 Ω
      Headlight relay (H-LP) terminal 5 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP] - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. Remove the headlight relay (H-LP) from the engine room relay block assembly.

    2. Disconnect the 2Q instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Headlight relay (H-LP) terminal 2 - 2Q-4 Always Below 1 Ω
      Headlight relay (H-LP) terminal 2 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. B003K42N01

      Remove the instrument panel junction block assembly.

      Click here

    2. Remove the body ECU from the instrument panel junction block assembly.

      Click here

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A-16 (HRLY) - 2Q-4 Always Below 1 Ω
      Result
      Result
      OK
      NG

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK

  8. CHECK BODY ECU


    1. Disconnect the A57*1 or A56*2 headlight assembly connector.


      • *1: for LH Side

      • *2: for RH Side

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A57-3 (LO) - Body ground Headlight dimmer switch (light control switch) in head position 11 to 14 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE HEADLIGHT LEVELING ECU ASSEMBLY Click here

    NG

    REPLACE BODY ECU Click here

  9. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP] - HEADLIGHT ASSEMBLY)


    1. Remove the headlight relay (H-LP) from the engine room relay block assembly.

    2. Disconnect the A57*1 or A56*2 headlight assembly connector.


      • *1: for LH Side

      • *2: for RH Side

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

      Standard Resistance
      for LH Side (B2430)
      Tester Connection Condition Specified Condition
      Headlight relay (H-LP) terminal 5 - A57-3 (LO) Always Below 1 Ω
      Headlight relay (H-LP) terminal 5 - Body ground Always 10 kΩ or higher
      for RH Side (B2431)
      Tester Connection Condition Specified Condition
      Headlight relay (H-LP) terminal 5 - A56-3 (LO) Always Below 1 Ω
      Headlight relay (H-LP) terminal 5 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the A57*1 or A56*2 headlight assembly connector.


      • *1: for LH Side

      • *2: for RH Side

    2. Disconnect the G40 headlight leveling ECU assembly connector.

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

      Standard Resistance
      for LH Side (B2430)
      Tester Connection Condition Specified Condition
      A57-4 (S) - G40-3 (LLEW) Always Below 1 Ω
      A57-1 (E) - Body ground Always Below 1 Ω
      A57-4 (S) - Body ground Always 10 kΩ or higher
      for RH Side (B2431)
      Tester Connection Condition Specified Condition
      A56-4 (S) - G40-2 (RLEW) Always Below 1 Ω
      A56-1 (E) - Body ground Always Below 1 Ω
      A56-4 (S) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. CHECK RH HEADLIGHT ASSEMBLY


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

      Click here

    2. Check for DTCs.

      Click here


      Body Electrical > HL AutoLeveling > Trouble Codes
      Result
      Result Proceed to
      DTC B2430 and B2431 are not output. A
      DTC B2430 or B2431 is output. B

    A

    END (HEADLIGHT ASSEMBLY WAS DEFECTIVE)

    B

    REPLACE HEADLIGHT LEVELING ECU ASSEMBLY Click here