LIGHTING SYSTEM Low Beam Headlight Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) controls the headlight relays.

WIRING DIAGRAM


  1. for Halogen Headlight

    A019L1SE02

  2. for HID Headlight

    A019MU8E04

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the intelligent tester on.

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

    5. Check that the relays operate.

      Main Body
      Tester Display Test Part Control Range Diagnostic Note
      Headlight Relay Headlight relays ON/OFF -
      OK
      Headlight relays operate. (Low beam headlights illuminate.)

    NG

    INSPECT POWER DISTRIBUTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY) Click here

    OK

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

  2. INSPECT POWER DISTRIBUTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY)


    1. A019LOXE04
      Text in Illustration
      *1

      Component without harness connected

      (Power Distributor (Engine Room Junction Block Assembly))

      Remove the power distributor (engine room junction block assembly) from the engine room relay block Click here.

    2. Connect a positive (+) lead from the battery to terminal 3A-1.

    3. Connect a negative (-) lead from the battery to terminals 3C-13 and 3C-17.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      3B-3 - Battery negative Always 11 to 14 V
      3B-4 - Battery negative Always 11 to 14 V

    NG

    REPLACE POWER DISTRIBUTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY) Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (BATTERY - POWER DISTRIBUTOR)


    1. A019LT1E01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Power Distributor (Engine Room Junction Block Assembly))

      Disconnect the 3A power distributor (engine room junction block assembly) connector.

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

      Standard Voltage
      Tester Connector Condition Specified Condition
      3A-1 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (POWER DISTRIBUTOR - BODY GROUND)


    1. A019OP0E01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Power Distributor (Engine Room Junction Block Assembly))

      Disconnect the 3C power distributor (engine room junction block assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3C-17 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (POWER DISTRIBUTOR - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. A019P32E01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Power Distributor (Engine Room Junction Block Assembly))
      *2

      Front view of wire harness connector

      (to Instrument Panel Junction Block Assembly)

      Disconnect the 3C power distributor (engine room junction block assembly) connector.

    2. Disconnect the 2F 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
      3C-13 - 2F-37 Always Below 1 Ω
      3C-13 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. A019LKHE04
      Text in Illustration
      *1

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      Remove the instrument panel junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2F-37 - A-15 (HRLY) Always Below 1 Ω
      2F-37 - Body ground Always 10 kΩ or higher

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here