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Home >> Toyota >> 2019 >> Sequoia SR5, 4WD >> Repair and Diagnosis >> Accessories & Equipment >> Headlights >> Lighting System (Exterior) - Diagnostic Codes & Circuit Tests >> Lighting System >> DTC B2430: LED Headlight LH Circuit Malfunction; DTC B2431: LED Headlight RH Circuit Malfunction [08/2019 - ] >> Procedure

DTC B2430: LED Headlight LH Circuit Malfunction; DTC B2431: LED Headlight RH Circuit Malfunction [08/2019 - ]: Procedure

  1. CHECK FOR DTC 
    1. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [08/2019 - ]

    2. Check for DTCs.

      Refer to DTC CHECK / CLEAR [08/2019 - ]

      OK

      DTC B2430 and B2431 are not output.

      Result

      Result Proceed to
      OK A
      NG (DTC B2430 and B2431 are output) B
      NG (DTC B2430 is output) C
      NG (DTC B2431 is output) D

    Result: 

    A 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2019 - ] 

    Result: 

    C 

    See step  6

    Result: 

    D 

    See step  9

    Result: 

    B 

    See step  2

  2. INSPECT HEADLIGHT RELAY (H-LP LO) 
    1. Remove the headlight relay (H-LP LO) from the engine room relay block and junction block.
    2. Inspect the headlight relay (H-LP LO).

      Refer to ON-VEHICLE INSPECTION [08/2017 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE HEADLIGHT RELAY (H-LP LO) 

    Result: 

    OK 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - BATTERY) 
    1. Remove the headlight relay (H-LP LO) from the engine room relay block and junction block.
      GTY747193Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Headlight Relay [H-LP LO])
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      Headlight relay (H-LP LO) terminal 1 - Body ground Always 11 to 14 V
      Headlight relay (H-LP LO) terminal 3 - Body ground Always 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - COWL SIDE JUNCTION BLOCK LH AND HEADLIGHT ASSEMBLY) 
    1. Remove the headlight relay (H-LP LO) from the engine room relay block and junction block.
    2. Disconnect the 3H cowl side junction block LH connector.
    3. Disconnect the A63 headlight assembly LH connector.
    4. Disconnect the A64 headlight assembly RH connector.
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      Headlight relay (H-LP LO) terminal 2 - 3H-31 Always Below 1 Ω
      Headlight relay (H-LP LO) terminal 5 - A63-2 (LO) Always Below 1 Ω
      Headlight relay (H-LP LO) terminal 2 or 3H-31 - Body ground Always 10 kΩ or higher
      Headlight relay (H-LP LO) terminal 5 or A63-2 (LO) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  5

  5. CHECK COWL SIDE JUNCTION BLOCK LH 
    1. Remove the cowl side junction block LH.

      Refer to REMOVAL [08/2019 - ]

      GTY759610Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component without harness connected
      (Cowl Side Junction Block LH)
    2. Remove the main body ECU (multiplex network body ECU) from the cowl side junction block LH.

      Refer to REMOVAL [08/2019 - ]

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      3H-31 - A-15 (HRLY) Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [08/2019 - ] 

    Result: 

    NG 

    REPLACE COWL SIDE JUNCTION BLOCK LH. Refer to  REMOVAL [08/2019 - ] 

  6. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - HEADLIGHT ASSEMBLY LH) 
    1. Remove the headlight relay (H-LP LO) from the engine room relay block and junction block.
    2. Disconnect the A63 headlight assembly LH 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 LO) terminal 5 - A63-2 (LO) Always Below 1 Ω
      Headlight relay (H-LP LO) terminal 5 or A63-2 (LO) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  7

  7. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY LH - MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU] AND BODY GROUND) 
    1. Disconnect the A63 headlight assembly LH connector.
    2. Disconnect the H133 main body ECU (multiplex network body ECU) connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A63-3 (S) - H133-16 (LLEW) Always Below 1 Ω
      A63-5 (E) - Body ground Always Below 1 Ω
      A63-3 (S) or H133-16 (LLEW) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  8

  8. CHECK HEADLIGHT ASSEMBLY LH 
    1. Temporarily replace the headlight assembly LH with a new or normally functioning one.

      Refer to REMOVAL [08/2017 - ]

    2. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [08/2019 - ]

    3. Check for DTCs.

      Refer to DTC CHECK / CLEAR [08/2019 - ]

      OK

      DTC B2430 is not output.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END (HEADLIGHT ASSEMBLY LH WAS DEFECTIVE) 

    Result: 

    NG 

    MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [08/2019 - ] 

  9. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - HEADLIGHT ASSEMBLY RH) 
    1. Remove the headlight relay (H-LP LO) from the engine room relay block and junction block.
    2. Disconnect the A64 headlight assembly RH 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 LO) terminal 5 - A64-2 (LO) Always Below 1 Ω
      Headlight relay (H-LP LO) terminal 5 or A64-2 (LO) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  10

  10. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY RH - MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU] AND BODY GROUND) 
    1. Disconnect the A64 headlight assembly RH connector.
    2. Disconnect the H133 main body ECU (multiplex network body ECU) connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A64-3 (S) - H133-3 (RLEW) Always Below 1 Ω
      A64-5 (E) - Body ground Always Below 1 Ω
      A64-3 (S) or H133-3 (RLEW) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  11

  11. CHECK HEADLIGHT ASSEMBLY RH 
    1. Temporarily replace the headlight assembly RH with a new or normally functioning one.

      Refer to REMOVAL [08/2017 - ]

    2. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [08/2019 - ]

    3. Check for DTCs.

      Refer to DTC CHECK / CLEAR [08/2019 - ]

      OK

      DTC B2431 is not output.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END (HEADLIGHT ASSEMBLY RH WAS DEFECTIVE) 

    Result: 

    NG 

    MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [08/2019 - ] 

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