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 (instrument panel junction block assembly). When the headlights are turned on, the main body ECU (instrument panel junction block assembly) 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 assembly LH

  • Main body ECU (instrument panel junction block assembly)

  • Harness or connector
B2431 LED headlight RH circuit malfunction

  • Headlight assembly RH

  • Main body ECU (instrument panel junction block assembly)

  • 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

A004PSEE08

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC B2430 or B2431 output does not occur.

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  2. INSPECT HEADLIGHT RELAY (H-LP)


    1. Remove the headlight relay.

    2. Inspect the headlight relay (HL-P) Click here.


    NG

    REPLACE HEADLIGHT RELAY (H-LP)

    OK

  3. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP] - MAIN BODY ECU [INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY] AND BATTERY)


    1. Remove the headlight relay (H-LP).

    2. Disconnect the D79 main body ECU (instrument panel junction block assembly) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Relay terminal 2 - 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
      Relay terminal 1 - D79-20 (HRLY) Always Below 1 Ω
      Relay terminal 1 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Remove the headlight relay (H-LP).

    2. Disconnect the A77*1 or A76*2 headlight assembly connector.


      • *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
      Relay terminal 5 - A77-4 (LO) Always Below 1 Ω
      Relay terminal 5 - Body ground Always 10 kΩ or higher
      for RH
      Tester Connection Condition Specified Condition
      Relay terminal 5 - A76-4 (LO) Always Below 1 Ω
      Relay terminal 5 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - MAIN BODY ECU [INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY] AND BODY GROUND)


    • *1: for LHD (w/o Seat Position Memory) and RHD (w/o Theft Deterrent System)

    • *2: for LHD (w/ Seat Position Memory) and RHD (w/ Theft Deterrent System)

    • *3: for LH

    • *4: for RH


    1. Disconnect the DC*1 *3, DH*1 *4, D79*2*3 or D81*2*4 main body ECU (instrument panel junction block assembly) connector.

    2. Disconnect the A77*3 or A76*4 headlight assembly connector.

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

      Standard Resistance
      for LH (for LHD (w/o Seat Position Memory) and RHD [w/o Theft Deterrent System])
      Tester Connection Condition Specified Condition
      A77-8 (S) - DH-5 (LLEW) Always Below 1 Ω
      A77-7 (E) - Body ground
      A77-8 (S) - Body ground Always 10 kΩ or higher
      for RH (for LHD (w/o Seat Position Memory) and RHD [w/o Theft Deterrent System])
      Tester Connection Condition Specified Condition
      A76-8 (S) - DC-5 (RLEW) Always Below 1 Ω
      A76-7 (E) - Body ground
      A76-8 (S) - Body ground Always 10 kΩ or higher
      for LH (w/ Seat Position Memory) and RHD [w/ Theft Deterrent System]
      Tester Connection Condition Specified Condition
      A77-8 (S) - D81-7 (LLEW) Always Below 1 Ω
      A77-7 (E) - Body ground
      A77-8 (S) - Body ground Always 10 kΩ or higher
      for RH (w/ Seat Position Memory) and RHD [w/ Theft Deterrent System]
      Tester Connection Condition Specified Condition
      A76-8 (S) - D79-24 (RLEW) Always Below 1 Ω
      A76-7 (E) - Body ground
      A76-8 (S) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HEADLIGHT ASSEMBLY


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

    2. Check for DTCs Click here.

      OK
      DTC B2430 or B2431 output does not occur.

    OK

    END (HEADLIGHT ASSEMBLY WAS DEFECTIVE)

    NG

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)