LIGHTING SYSTEM High Beam Headlight Circuit

DESCRIPTION

The main body ECU (network gateway ECU) receives headlight dimmer switch information signals, and illuminates the high beam headlight.

WIRING DIAGRAM

A004IYZE04
*a DIM
*b from Battery
*c Main Body ECU (Network Gateway ECU)
*d to High Beam Headlight

CAUTION / NOTICE / HINT

Tech Tips

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

PROCEDURE


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


    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. Check that the relay operates.

      Main Body
      Tester Display Test Part Control Range Diagnostic Note
      Head Light Hi Headlight dimmer relay ON/OFF -
      OK
      Relay operates (high beam headlights illuminate).
      Result
      Result Proceed to
      NG A
      OK B

    B

    REPLACE MAIN BODY ECU (NETWORK GATEWAY ECU) Click here

    A

  2. INSPECT DIM RELAY


    1. Remove the DIM relay from the engine room relay block.

    2. Inspect the DIM relay Click here.


    NG

    REPLACE DIM RELAY

    OK

  3. CHECK HARNESS AND CONNECTOR (BATTERY - DIM RELAY)

    A004K5DE01
    Text in Illustration
    *a

    Engine Room Relay Block

    (DIM Relay Terminal)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Relay terminal 5 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (DIM RELAY - MAIN BODY ECU (NETWORK GATEWAY ECU))


    1. Disconnect the A73 main body ECU (network gateway ECU) connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      Relay terminal 2 - A73-11 (DIM) Always Below 1 Ω
      Relay terminal 1 - A73-23 Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A73-11 (DIM) - Body ground Always 10 kΩ or higher
      A73-23 - Body ground Always 10 kΩ or higher

    OK

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR