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DTC B2430: LED Headlight LH Circuit Malfunction; DTC B2431: LED Headlight RH Circuit Malfunction: Procedure

WARNING: This page is about a different variant/trim than selected.
  1. CHECK FOR DTC 
    1. Clear the DTCs. Refer to DTC CHECK / CLEAR .
    2. Check for DTCs. Refer to DTC CHECK / CLEAR .

      Result

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

    B → See step   2 

    C → See step   6 

    A → See step   16 

  2. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - P/I 2 FUSE AND BODY GROUND) 
    1. Disconnect the 1H No. 1 integration relay connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connector Condition Specified Condition
      1H-7 (BATT) - Body ground Power switch off 11 to 14 V
    3. Disconnect the 1G No. 1 integration relay connector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      1G-22 (GND1) - Body ground Always Below 1 Ω
      1H-3 (GND2) - Body ground Always Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY) 
    1. Disconnect the 2C instrument panel junction block assembly connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      1G-9 (HL4) - 2C-32 Always Below 1 Ω
      1G-9 (HL4) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  4. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 
    1. Remove the instrument panel junction block assembly. Refer to REMOVAL .
    2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.
      Fig 1: Inspecting 2C & MB Connector Terminals
      GTY340998Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      2C-32 - MB-15 (HRLY) Always Below 1 Ω
      2C-32 - Body ground Always 10 kΩ or higher
      TEXT IN ILLUSTRATION

      *a Component without harness connected
      (Instrument Panel Junction Block Assembly)

    NG → See step   15 

    OK: Go to next step 

  5. CHECK NO. 1 INTEGRATION RELAY 
    1. Replace the No. 1 integration relay with a new or known good one. Refer to REMOVAL .
    2. Check for DTCs. Refer to DTC CHECK / CLEAR .

      OK

      DTC B2430 and B2431 are not output.

    NG → See step   13 

    OK → END (NO. 1 INTEGRATION RELAY WAS DEFECTIVE) 

  6. CHECK HARNESS AND CONNECTOR (LIGHT CONTROL ECU POWER SOURCE) 
    1. Disconnect the A81 or A93 headlight assembly connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      LH SIDE (B2430)

      Tester Connection Condition Specified Condition
      A81-3 (LO) - Body ground Light control switch in head position 11 to 14 V
      RH SIDE (B2431)

      Tester Connection Condition Specified Condition
      A93-3 (LO) - Body ground Light control switch in head position 11 to 14 V

    NG → See step   11 

    OK: Go to next step 

  7. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - BODY GROUND) 
    1. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      LH SIDE (B2430)

      Tester Connection Condition Specified Condition
      A81-1 (E) - Body ground Always Below 1 Ω
      RH SIDE (B2431)

      Tester Connection Condition Specified Condition
      A93-1 (E) - Body ground Always Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  8. CHECK HEADLIGHT ASSEMBLY (INPUT VOLTAGE) 
    1. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      LH SIDE (B2430)

      Tester Connection Condition Specified Condition
      A81-2 (IN2) - Body ground Power switch on (IG) and light control switch in head position 11 to 14 V
      RH SIDE (B2431)

      Tester Connection Condition Specified Condition
      A93-2 (IN1) - Body ground Power switch on (IG) and light control switch in head position 11 to 14 V

    NG → See step   12 

    OK: Go to next step 

  9. CHECK LIGHT CONTROL ECU 
    1. Replace the light control ECU with a new or known good one. Refer to REMOVAL .
    2. Check for DTCs. Refer to DTC CHECK / CLEAR .

      OK

      DTC B2430 or B2431 is not output.

    NG → See step   10 

    OK → END (LIGHT CONTROL ECU WAS DEFECTIVE) 

  10. CHECK HEADLIGHT UNIT 
    1. Replace the headlight unit with a new or known good one. Refer to REMOVAL .
    2. Check for DTCs. Refer to DTC CHECK / CLEAR .

      OK

      DTC B2430 or B2431 are not output.

    NG → See step   13 

    OK → END (HEADLIGHT UNIT WAS DEFECTIVE) 

  11. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - NO. 1 INTEGRATION RELAY) 
    1. Disconnect the 1G No. 1 integration relay connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      LH SIDE (B2430)

      Tester Connection Condition Specified Condition
      1G-2 (HLPL) - A81-3 (LO) Always Below 1 Ω
      1G-2 (HLPL) - Body ground Always 10 kΩ or higher
      RH SIDE (B2431)

      Tester Connection Condition Specified Condition
      1G-1 (HLPR) - A93-3 (LO) Always Below 1 Ω
      1G-1 (HLPR) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   14 

  12. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - HEADLIGHT ASSEMBLY) 
    1. Disconnect the L8 main body ECU (multiplex network body ECU) connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      LH SIDE (B2430)

      Tester Connection Condition Specified Condition
      L8-21 (LLEW) - A81-2 (IN2) Always Below 1 Ω
      L8-21 (LLEW) - Body ground Always 10 kΩ or higher
      RH SIDE (B2431)

      Tester Connection Condition Specified Condition
      L8-5 (RLEW) - A93-2 (IN1) Always Below 1 Ω
      L8-5 (RLEW) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   13 

  13. REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL 
  14. REPLACE NO. 1 INTEGRATION RELAY. Refer to  REMOVAL 
  15. REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to  REMOVAL 
  16. USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING 
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