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LIGHTING SYSTEM, Diagnostic DTC:B2430, B2431

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

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

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WIRING DIAGRAM

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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.

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

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  • As the door control battery is installed between the vehicle battery and body ECU, first perform the inspections to confirm that there are no malfunctions in the power source circuit for the body ECU before performing this troubleshooting procedure.*

    *: w/ Power Door Lock

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Tip:

  • 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.

  • The light system (exterior) uses the CAN communication system. First perform the communication function checks in "How to Proceed with Troubleshooting" to confirm that there are no communication malfunctions before proceeding with troubleshooting.

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PROCEDURE


  1. Click here

    CLEAR DTC


    1. Clear the DTCs.

      Click here


      1. Body Electrical > HL AutoLeveling > Clear DTCs


      Result
      Proceed to
      NEXT

  2. Click here

    CHECK FOR DTC


    1. Check for DTCs.

      Click here


      1. Body Electrical > HL AutoLeveling > Trouble Codes


      Result
      Result Proceed to
      Both DTC B2430 and B2431 are not output. A
      Both DTC B2430 and B2431 are output. B
      Only DTC B2430 or B2431 is output. C

  3. Click here

    INSPECT HEADLIGHT RELAY (H-LP)


    1. B002521N01

      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

  4. Click here

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


    1. B0026TFC01
      *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

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  5. Click here

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


    • *1: for LH Side

    • *2: for RH Side


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

    2. Disconnect the A18*1 or A17*2 headlight 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 5 - A18-4 (LO)*1 Always Below 1 Ω
      Headlight relay (H-LP) terminal 5 - A17-4 (LO)*2 Always Below 1 Ω
      Headlight relay (H-LP) terminal 5 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  6. Click here

    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 - 2Q-4 Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  7. Click here

    INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. B0027D7N01

      Remove the instrument panel junction block assembly.

      for LHD:

      Click here

      for RHD:

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

      for LHD:

      Click here

      for RHD:

      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

    • OKClick here
    • NG

      REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY for LHD:

      REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLYClick here

      REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY for RHD:

      REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLYClick here

  8. Click here

    CHECK BODY ECU


    • *1: for LH Side

    • *2: for RH Side


    1. Disconnect the A18*1 or A17*2 headlight assembly connector.

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

      Standard Voltage
      Table 1. for LH Side
      Tester Connection Condition Specified Condition
      A18-4 (LO) - Body ground Headlight dimmer switch (light control switch) in head position 11 to 14 V
      Table 2. for RH Side
      Tester Connection Condition Specified Condition
      A17-4 (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 ASSEMBLYClick here

    • NG

      REPLACE BODY ECU for LHD:

      REPLACE BODY ECUClick here

      REPLACE BODY ECU for RHD:

      REPLACE BODY ECUClick here

  9. Click here

    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 A18*1 or A17*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
      Table 3. for LH Side (B2430)
      Tester Connection Condition Specified Condition
      Headlight relay (H-LP) terminal 5 - A18-4 (LO) Always Below 1 Ω
      Headlight relay (H-LP) terminal 5 - Body ground Always 10 kΩ or higher
      Table 4. for RH Side (B2431)
      Tester Connection Condition Specified Condition
      Headlight relay (H-LP) terminal 5 - A17-4 (LO) Always Below 1 Ω
      Headlight relay (H-LP) terminal 5 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  10. Click here

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


    1. Disconnect the A18*1 or A17*2 headlight assembly connector.


      • *1: for LH Side

      • *2: for RH Side

    2. Disconnect the G80 headlight leveling ECU assembly connector.

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

      Standard Resistance
      Table 5. for LH Side (B2430)
      Tester Connection Condition Specified Condition
      A18-6 (S) - G80-3 (LLEW) Always Below 1 Ω
      A18-5 (E) - Body ground Always Below 1 Ω
      A18-6 (S) - Body ground Always 10 kΩ or higher
      Table 6. for RH Side (B2431)
      Tester Connection Condition Specified Condition
      A17-6 (S) - G80-2 (RLEW) Always Below 1 Ω
      A17-5 (E) - Body ground Always Below 1 Ω
      A17-6 (S) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  11. Click here

    CHECK HEADLIGHT ASSEMBLY


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

      Click here

    2. Check for DTCs.

      Click here


      1. Body Electrical > HL AutoLeveling > Trouble Codes


      Result
      Result Proceed to
      Both DTC B2430 and B2431 are not output. A
      Only DTC B2430 or B2431 is output. B

    • A

      END (HEADLIGHT ASSEMBLY WAS DEFECTIVE)

    • B

      REPLACE HEADLIGHT LEVELING ECU ASSEMBLYClick here