LIGHTING SYSTEM Low Beam Headlight Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) controls the low beam headlights via the H-LP relay.

WIRING DIAGRAM


  1. for LED Headlight:

    A01I08NE01

  2. for Halogen Headlight:

    A01HYTME01

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING TECHSTREAM


    1. Connect the Techstream to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the Techstream on.

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

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

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

    NG

    INSPECT H-LP RELAY Click here

    OK

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

  2. INSPECT H-LP RELAY


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

    2. A01HXDPE04
      Text in Illustration
      *a

      Component without harness connected

      (H-LP Relay)

      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

    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 2 - Body ground Always 11 to 14 V
      Relay Terminal 5 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. for LED Headlight:


      1. Disconnect the A86 headlight assembly LH connector.

      2. Disconnect the A89 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 - A86-1 (LO) Always Below 1 Ω
        Relay Terminal 3 - A89-1 (LO) Always Below 1 Ω
        Relay Terminal 3 - Body ground Always 10 kΩ or higher

    2. for Halogen Headlight:


      1. Disconnect the A17 headlight assembly LH connector.

      2. Disconnect the A60 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 - A17-2 (LO) Always Below 1 Ω
        Relay Terminal 3 - A60-2 (LO) Always Below 1 Ω
        Relay Terminal 3 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the 3D 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 1 - 3D-12 Always Below 1 Ω
      Relay Terminal 1 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. A01HXSME27
      Text in Illustration
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      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
      3D-12 - MB-15 (HRLY) Always Below 1 Ω

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK

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