LIGHTING SYSTEM Headlight Relay Circuit

DESCRIPTION

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

WIRING DIAGRAM

A01FHGDE01

INSPECTION PROCEDURE

Note


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

  • Recognition code registration is necessary when replacing the main body ECU (multiplex network body ECU).

  • If the main body ECU (multiplex network body ECU) is replaced, refer to the Service Bulletin.

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (H-LP LO RELAY)


    1. Using the GTS, 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 come on).

    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. A01FDTHE01

      Remove the headlight relay from the No. 2 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 RELAY)

    OK

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


    1. A01FHWYE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Headlight Relay)

      Remove the headlight relay from the No. 2 engine room relay block.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Headlight relay terminal 3- Body ground Always 11 to 14 V
      Headlight relay terminal 1 - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Remove the headlight relay from the No. 2 engine room relay block.

    2. Disconnect the 5D cowl side junction block LH 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 - 5D-9 Always Below 1 Ω
      5D-9 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT COWL SIDE JUNCTION BLOCK LH


    1. A01FGFVE02

      Remove the cowl side junction block LH Click here.

    2. Remove the main body ECU from the cowl side junction block LH 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) - 5D-9 Always Below 1 Ω

    NG

    REPLACE COWL SIDE JUNCTION BLOCK LH Click here

    OK

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