LIGHTING SYSTEM Low Beam Headlight Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) controls the headlight relays located within the No. 1 integration relay.

WIRING DIAGRAM


  1. for Halogen Headlight

    B001LNKE02

  2. for LED Headlight

    B001KH1E03

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 power switch on (IG).

    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.

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

    OK

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

    NG

  2. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - AUXILIARY BATTERY AND BODY GROUND)


    1. Disconnect the 1H and 1G No. 1 integration relay connectors.

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

      Standard Voltage
      Tester Connector Condition Specified Condition
      1H-7 (BATT) - Body ground Power switch off 11 to 14 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      1G-22 (GND1) - Body ground Always Below 1 Ω
      1H-3 (GND2) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the 2C 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
      1G-9 (HL4) - 2C-32 Always Below 1 Ω
      1G-9 (HL4) or 2C-32 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

    B001KZBC46
    *a

    Component without harness connected

    (Instrument Panel Junction Block Assembly)

    		 - -

    1. Remove the instrument panel junction block assembly.

      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.

      Standard Resistance
      Tester Connection Condition Specified Condition
      2C-32 - A-15 (HRLY) Always Below 1 Ω

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK

  5. REPLACE NO. 1 INTEGRATION RELAY


    1. Replace the No. 1 integration relay with a new or a known good one.

      Click here

    2. Check that the low beam headlights operate normally.

      OK
      Low beam headlights operate normally.

    OK

    END (NO. 1 INTEGRATION RELAY WAS DEFECTIVE)

    NG

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