LIGHTING SYSTEM High Beam Headlight Circuit

DESCRIPTION

The illumination of the high beam headlights is controlled by the headlight light control ECU sub-assembly.

WIRING DIAGRAM

B006RIFE03

CAUTION / NOTICE / HINT

Note


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

  • After the headlight light control ECU sub-assembly LH (main) is replaced, vehicle information registration and initialization are necessary.

    Click here

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

    Click here

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (HEAD LIGHT HI)


    1. Using the GTS, perform the Active Test.

      Click here


      Body Electrical > Main Body > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Head Light Hi Illuminates the high beam headlights ON or OFF -

      Body Electrical > Main Body > Active Test
      Tester Display
      Head Light Hi
      Result
      Result Proceed to
      The Active Test is performed normally A
      The Active Test is not performed normally for the right side light only B
      The Active Test is not performed normally for the left side light only C

    A

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    C

    INSPECT HEADLIGHT HOUSING SUB-ASSEMBLY LH (WIRE HARNESS ASSEMBLY) Click here

    B

  2. INSPECT HEADLIGHT HOUSING SUB-ASSEMBLY RH (WIRE HARNESS ASSEMBLY)


    1. B006MCVN01

      Remove the headlight sub-assembly RH.

      for ALPHARD:

      Click here

      for VELLFIRE:

      Click here

    2. Remove the headlight unit assembly RH from the headlight sub-assembly RH.

      for ALPHARD:

      Click here

      for VELLFIRE:

      Click here

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B-10 - A-1 Always Below 1 Ω
      B-1 - A-2 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEADLIGHT HOUSING SUB-ASSEMBLY RH (WIRE HARNESS ASSEMBLY) for ALPHARD: REPLACE HEADLIGHT HOUSING SUB-ASSEMBLY RH (WIRE HARNESS ASSEMBLY) Click here
    REPLACE HEADLIGHT HOUSING SUB-ASSEMBLY RH (WIRE HARNESS ASSEMBLY) for VELLFIRE: REPLACE HEADLIGHT HOUSING SUB-ASSEMBLY RH (WIRE HARNESS ASSEMBLY) Click here

    OK

  3. REPLACE HEADLIGHT UNIT ASSEMBLY RH


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

      for ALPHARD:

      Click here

      for VELLFIRE:

      Click here

    2. Check that the operation of the lighting system returns to normal.

      Result
      Proceed to
      OK
      NG

    OK

    END (HEADLIGHT UNIT ASSEMBLY RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT LIGHT CONTROL ECU SUB-ASSEMBLY RH (SUB) Click here

  4. INSPECT HEADLIGHT HOUSING SUB-ASSEMBLY LH (WIRE HARNESS ASSEMBLY)


    1. B006MCVN01

      Remove the headlight sub-assembly LH.

      for ALPHARD:

      Click here

      for VELLFIRE:

      Click here

    2. Remove the headlight unit assembly LH from the headlight sub-assembly LH.

      for ALPHARD:

      Click here

      for VELLFIRE:

      Click here

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B-10 - A-1 Always Below 1 Ω
      B-1 - A-2 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEADLIGHT HOUSING SUB-ASSEMBLY LH (WIRE HARNESS ASSEMBLY) for ALPHARD: REPLACE HEADLIGHT HOUSING SUB-ASSEMBLY LH (WIRE HARNESS ASSEMBLY) Click here
    REPLACE HEADLIGHT HOUSING SUB-ASSEMBLY LH (WIRE HARNESS ASSEMBLY) for VELLFIRE: REPLACE HEADLIGHT HOUSING SUB-ASSEMBLY LH (WIRE HARNESS ASSEMBLY) Click here

    OK

  5. REPLACE HEADLIGHT UNIT ASSEMBLY LH


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

      for ALPHARD:

      Click here

      for VELLFIRE:

      Click here

    2. Check that the operation of the lighting system returns to normal.

      Result
      Proceed to
      OK
      NG

    OK

    END (HEADLIGHT UNIT ASSEMBLY LH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT LIGHT CONTROL ECU SUB-ASSEMBLY LH (MAIN) Click here