LIGHTING SYSTEM Low Beam Headlight Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) controls the low beam headlights.

WIRING DIAGRAM


  1. for LED Headlight

    A01T8ZRE11

  2. for Halogen Headlight

    A01TAMAE11

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Main Body / Active Test.

    5. Perform the Active Test according to the display on the GTS.


      Body Electrical > Main Body > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Headlight Relay Headlight relay (Low beam headlights) ON/OFF -

      Body Electrical > Main Body > Active Test
      Tester Display
      Headlight Relay
      OK
      Headlight relay operates. (Low beam headlights illuminate.)
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

  2. INSPECT H-LP RELAY


    1. Remove the H-LP relay from the engine room relay block and junction block assembly.

    2. A01T9HXN04

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 Voltage not applied between terminals 1 and 2 10 kΩ or higher
      3 - 5 Voltage applied between terminals 1 and 2 Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE H-LP RELAY

    OK

  3. CHECK HARNESS AND CONNECTOR (H-LP-MAIN FUSE - H-LP RELAY)


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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Relay terminal 1 - Body ground Always 11 to 14 V
      Relay terminal 5 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (H-LP RELAY - HEADLIGHT ASSEMBLY LH AND HEADLIGHT ASSEMBLY RH)


    1. for LED Headlight (except Sedan):


      1. Disconnect the A70 headlight assembly LH connector.

      2. Disconnect the A73 headlight assembly RH connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        Relay terminal 3 - A70-4 (LO) Always Below 1 Ω
        Relay terminal 3 - A73-4 (LO) Always Below 1 Ω
        Relay terminal 3 - Body ground Always 10 kΩ or higher

    2. for LED Headlight (for Sedan):


      1. Disconnect the A184 headlight assembly LH connector.

      2. Disconnect the A183 headlight assembly RH connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        Relay terminal 3 - A184-2 (LO) Always Below 1 Ω
        Relay terminal 3 - A183-2 (LO) Always Below 1 Ω
        Relay terminal 3 - Body ground Always 10 kΩ or higher

    3. for Halogen Headlight (except Sedan):


      1. Disconnect the A70 headlight assembly LH connector.

      2. Disconnect the A73 headlight assembly RH connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        Relay terminal 3 - A70-4 (LO) Always Below 1 Ω
        Relay terminal 3 - A73-4 (LO) Always Below 1 Ω
        Relay terminal 3 - Body ground Always 10 kΩ or higher

    4. for Halogen Headlight (for Sedan):


      1. Disconnect the A153 headlight assembly LH connector.

      2. Disconnect the A152 headlight assembly RH connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        Relay terminal 3 - A153-2 (LO) Always Below 1 Ω
        Relay terminal 3 - A152-2 (LO) Always Below 1 Ω
        Relay terminal 3 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (H-LP RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the 3A 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
      Relay terminal 2 - 3A-35 Always Below 1 Ω
      Relay terminal 2 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. Remove the instrument panel junction block assembly.

      for LHD: Click here

      for RHD: Click here

    2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

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

      A01TCPEC01
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      3A-35 - MB-15 (HRLY) Always Below 1 Ω
      3A-35 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) for LHD: Click here
    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) for RHD: Click here

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY for LHD: Click here
    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY for RHD: Click here