LIGHTING SYSTEM Headlight Relay Circuit

DESCRIPTION

The main body ECU receives headlight dimmer switch information signals and illuminates the low beam headlights.

WIRING DIAGRAM

A01DN6KE01

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (HEADLIGHT RELAY)


    1. Using the intelligent tester, perform the Active Test Click here.

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

    NG

    INSPECT HEADLIGHT RELAY (H-LP LO) Click here

    OK

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

  2. INSPECT HEADLIGHT RELAY (H-LP LO)


    1. A01DP77E04

      Remove the headlight relay from the engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 Battery voltage not applied between terminals 1 and 2 10 kΩ or higher
      3 - 5 Battery voltage applied between terminals 1 and 2 Below 1 Ω

    NG

    REPLACE HEADLIGHT RELAY (H-LP LO)

    OK

  3. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - BATTERY)


    1. A01DOP7E01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Headlight Relay [H-LP LO])

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Headlight relay terminal 1 - Body ground Always 11 to 14 V
      Headlight relay terminal 5 - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - DRIVER SIDE JUNCTION BLOCK ASSEMBLY)


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

    2. Disconnect the 2F driver side junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Headlight relay terminal 2 - 2F-40 Always Below 1 Ω
      2F-40 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT DRIVER SIDE JUNCTION BLOCK ASSEMBLY

    A01DS7ZE03

    1. Remove the driver side junction block assembly Click here.

    2. Remove the main body ECU from the driver side junction block assembly Click here.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A-15 (HRLY) - 2F-40 Always Below 1 Ω

    NG

    REPLACE DRIVER SIDE JUNCTION BLOCK ASSEMBLY Click here

    OK

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