LIGHTING SYSTEM LO-beam Headlight does not Illuminate

DESCRIPTION

The main body ECU receives a headlight switch information signal from the light control switch, and illuminates the headlight low beam.

WIRING DIAGRAM

A01ENAME05

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (HEADLIGHT DIMMER SWITCH)


    1. Using the intelligent tester, read the Data List Click here.

      Main Body
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Head Light SW (HEAD) Headlight switch signal/ON or OFF

      ON: Headlight switch (Head) on

      OFF: Headlight switch (Head) off

      		 -
      OK
      When the headlight dimmer switch operation is performed, the result will be the same as above.

    NG

    INSPECT HEADLIGHT DIMMER SWITCH Click here

    OK

  2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (HEADLIGHT)


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

      Main Body
      Tester Display Test Part Control Range Diagnostic Note
      Headlight Relay Headlight ON/OFF -
      OK
      Headlight low beam turns on/off.

    NG

    INSPECT HEADLIGHT RELAY (HEAD LO) Click here

    OK

    REPLACE MAIN BODY ECU

  3. INSPECT HEADLIGHT DIMMER SWITCH

    A01EROOE03

    1. A01ER6LE08

      for LHD:


      1. Remove the headlight dimmer switch Click here.

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

        Standard Resistance
        Tester Connection Switch Condition Specified Condition
        20 (H) - 12 (EL) Headlight dimmer switch (Light control switch) head Below 1 Ω
        18 (T) - 12 (EL)
        20 (H) - 12 (EL) Headlight dimmer switch (Light control switch) off 10 kΩ or higher
        18 (T) - 12 (EL)

    2. for RHD:


      1. Remove the headlight dimmer switch Click here.

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

        Standard Resistance
        Tester Connection Switch Condition Specified Condition
        11 (H) - 19 (EL) Headlight dimmer switch (Light control switch) head Below 1 Ω
        13 (T) - 19 (EL)
        11 (H) - 19 (EL) Headlight dimmer switch (Light control switch) off 10 kΩ or higher
        13 (T) - 19 (EL)
        Result
        Result Proceed to
        OK A
        NG (for LHD) B
        NG (for RHD) C

    B

    REPLACE HEADLIGHT DIMMER SWITCH Click here

    C

    REPLACE HEADLIGHT DIMMER SWITCH Click here

    A

  4. CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER SWITCH - MAIN BODY ECU AND BODY GROUND)


    1. A01ESD7E02

      Disconnect the E14 switch connector.

    2. Disconnect the E1 and E2 ECU connectors.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      E14-20 (H) - E2-17 (HEAD) Always Below 1 Ω
      E14-18 (T) - E1-23 (TAIL)
      E14-12 (EL) - Body ground
      E14-20 (H) - Body ground Always 10 kΩ or higher
      E14-18 (T) - Body ground
      for RHD
      Tester Connection Condition Specified Condition
      E14-11 (H) - E2-17 (HEAD) Always Below 1 Ω
      E14-13 (T) - E1-23 (TAIL)
      E14-19 (EL) - Body ground
      E14-11 (H) - Body ground Always 10 kΩ or higher
      E14-18 (T) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE MAIN BODY ECU

  5. INSPECT HEADLIGHT RELAY (HEAD LO)


    1. A01EQFSE10

      Remove the HEAD LO 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 to terminals 1 and 2 10 kΩ or higher
      Battery voltage applied to terminals 1 and 2 Below 1 Ω

    NG

    REPLACE HEAD LO RELAY

    OK

  6. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [HEAD LO] - BATTERY)


    1. A01ES2ZE04

      Remove the HEAD LO relay from the engine room relay block.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      HEAD LO Relay terminal 1 - Body ground Engine switch on (IG) 11 to 14 V
      HEAD LO Relay terminal 5 - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK HARNESS AND CONNECTOR (HEADLIGHT - HEAD LO RELAY AND BODY GROUND)

    A01ENHME05

    1. Remove the HEAD LO relay from the engine room relay block.

    2. Disconnect the A55*1 or A56*2 light connector.


      • *1: for LH

      • *2: for RH

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

      Standard Resistance
      for LH
      Tester Connection Condition Specified Condition
      HEAD LO relay terminal 3 - A55-3 (LO) Always Below 1 Ω
      A55-4 (E) - Body ground
      A55-3 (LO) - Body ground Always 10 kΩ or higher
      for RH
      Tester Connection Condition Specified Condition
      HEAD LO relay terminal 3 - A56-3 (LO) Always Below 1 Ω
      A56-4 (E) - Body ground
      A56-3 (LO) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HEADLIGHT (LOW BEAM)


    1. A01ES0PE07

      Disconnect the 2B ECU connector.

    2. Using a service wire, connect terminal 2B-18 (HRLY) on the wire harness side and the body ground.

    3. Check that the headlight low beam illuminates.

      OK
      Headlight low beam illuminates.

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (HEADLIGHT RELAY - MAIN BODY ECU)

    OK

    REPLACE MAIN BODY ECU