LIGHTING SYSTEM High Beam Headlight Circuit

DESCRIPTION

for TMC, TMMR Made:

The main body ECU (multiplex network body ECU) controls the high beam headlights via the engine room junction block assembly.

for TMMK Made:

The main body ECU (multiplex network body ECU) controls the high beam headlights via the DIMMER relay.

WIRING DIAGRAM


  1. for TMC, TMMR Made:

    B000MZXE01

  2. for TMMK Made:

    B000IUKE04

INSPECTION PROCEDURE

PROCEDURE


  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

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

    5. Perform the Active Test according to the display on the intelligent tester.

      Main Body
      Tester Display Test Part Control Range Diagnostic Note
      Head Light Hi High beam headlights ON/OFF -
      OK
      The high beam headlights illuminate.
      Result
      Result Proceed to
      OK A
      NG (for TMC, TMMR Made) B
      NG (for TMMK Made) C

    B

    CHECK ENGINE ROOM JUNCTION BLOCK ASSEMBLY Click here

    C

    INSPECT DIMMER RELAY Click here

    A

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

  2. CHECK ENGINE ROOM JUNCTION BLOCK ASSEMBLY


    1. Using a voltmeter, check the signal reading of the engine room junction block assembly Click here.

      OK
      Output signal reading is normal.

    NG

    INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY (RESULTS OF SIGNAL READING CHECK) Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY POWER SOURCE AND BODY GROUND) Click here


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - 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
      1F-5 - 3D-39 Always Below 1 Ω
      3D-39 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. B000M6KE64
      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-39 - MB-26 (DIM) Always Below 1 Ω

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK

  6. CHECK ENGINE ROOM JUNCTION BLOCK ASSEMBLY


    1. Replace the engine room junction block assembly with a new or a known good one Click here.

    2. Check that the high beam headlights operate normally.

      OK
      The high beam headlights operate normally.

    NG

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

    OK

    END (ENGINE ROOM JUNCTION BLOCK ASSEMBLY WAS DEFECTIVE)

  7. INSPECT DIMMER RELAY


    1. B000H91E21
      Text in Illustration
      *a

      Component without harness connected

      (DIMMER Relay)

      Remove the DIMMER relay from the No. 2 engine room relay block and junction block assembly.

    2. 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 DIMMER RELAY

    OK

  8. CHECK HARNESS AND CONNECTOR (POWER SOURCE - DIMMER RELAY)


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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Relay Terminal 1 - Body ground Always 11 to 14 V
      Relay Terminal 3 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK HARNESS AND CONNECTOR (DIMMER RELAY - HEADLIGHT ASSEMBLY)


    1. Disconnect the A91 headlight assembly LH connector.

    2. Disconnect the A95 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 5 - A91-3 (HI) Always Below 1 Ω
      Relay Terminal 5 - A95-3 (HI) Always Below 1 Ω
      Relay Terminal 5 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. CHECK HARNESS AND CONNECTOR (DIMMER 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 2 - 3D-39 Always Below 1 Ω
      Relay Terminal 2 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. B000M6KE54
      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-39 - MB-26 (DIM) Always Below 1 Ω

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK

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