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 main body ECU. When the headlights are turned on, the main body ECU receives a signal from the headlight assembly and detects the illumination condition of the low beam headlights.

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

  • Headlight unit LH

  • Main body ECU (multiplex network body ECU)

  • Harness or connector
B2431 LED headlight RH circuit malfunction

  • Headlight unit RH

  • Main body ECU (multiplex network body ECU)

  • Harness or connector

Tech Tips

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

WIRING DIAGRAM

A01DUG5E01

INSPECTION PROCEDURE

Note

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

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 HEADLIGHT RELAY (H-LP LO) Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  3. INSPECT HEADLIGHT RELAY (H-LP LO)


    1. A01DP77E04

      Remove the headlight relay 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

    NG

    REPLACE HEADLIGHT RELAY (H-LP LO)

    OK

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


    1. A01DOP7E01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Headlight Relay [H-LP LO])

      Remove the headlight relay 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 terminal 5 - Body ground Always 11 to 14 V
      Headlight relay terminal 1 - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - DRIVER SIDE JUNCTION BLOCK ASSEMBLY)


    1. Remove the headlight relay from the engine room relay block assembly.

    2. Disconnect the 2F driver side 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 terminal 2 - 2F-40 Always Below 1 Ω
      2F-40 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT DRIVER SIDE JUNCTION BLOCK ASSEMBLY


    1. A01DS7ZE01

      Remove the driver side junction block assembly Click here.

    2. Remove the main body ECU from the driver side 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-15 (HRLY) - 2F-40 Always Below 1 Ω

    NG

    REPLACE DRIVER SIDE JUNCTION BLOCK ASSEMBLY Click here

    OK

  7. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - HEADLIGHT)


    • *1: for LH

    • *2: for RH


    1. Remove the headlight relay from the engine room relay block assembly.

    2. Disconnect the A86*1 and A87*2 headlight connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Headlight relay terminal 3 - A86-1 (B)*1 Always Below 1 Ω
      Headlight relay terminal 3 - A87-1 (B)*2 Always Below 1 Ω
      Headlight relay terminal 3 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (HEADLIGHT - MAIN BODY ECU AND BODY GROUND)


    1. Disconnect the A86*1 or A87*2 headlight unit connector.


      • *1: for LH

      • *2: for RH

    2. Disconnect the G64 main body ECU connector.

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

      Standard Resistance
      for LH
      Tester Connection Condition Specified Condition
      A86-3 (S) - G64-21 (LLEW) Always Below 1 Ω
      A86-2 (LO) - Body ground Below 1 Ω
      A86-3 (S) - Body ground 10 kΩ or higher
      for RH
      Tester Connection Condition Specified Condition
      A87-3 (S) - G46-8 (RLEW) Always Below 1 Ω
      A87-2 (LO) - Body ground Below 1 Ω
      A87-3 (S) - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK HEADLIGHT UNIT


    1. Temporarily replace the headlight 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

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

    OK

    REPLACE HEADLIGHT UNIT Click here