LIGHTING SYSTEM Front Fog Light Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) controls the front fog lights via the engine room junction block assembly.

WIRING DIAGRAM

A00062FE02

CAUTION / NOTICE / HINT

Note


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

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

PROCEDURE


  1. CHECK OPERATION (TAILLIGHTS)


    1. Check the operation of the taillights.

      OK
      Taillights operate normally.

    NG

    GO TO PROBLEM SYMPTOMS TABLE Click here

    OK

  2. PERFORM ACTIVE TEST USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

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

    5. Check that the relay operates.

      Main Body
      Tester Display Test Part Control Range Diagnostic Note
      Front Fog Light Relay Front fog light relay ON/OFF Light control switch is in tail position
      OK
      Front fog light relay operates. (Front fog lights come on.)

    OK

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

    NG

  3. 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

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


    1. Remove the engine room junction block assembly from the engine room relay block and junction block assembly Click here.

      A0005W1E01
      Text in Illustration
      *a

      Component without engine room junction block assembly connected

      (Engine Room Relay Block and Junction Block Assembly)

      		 - -

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A-1 (BATT) - Body ground Power switch off 11 to 14 V
      B-1 (ALT) - Body ground Power switch off 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1F-3 (GND1) - Body ground Always Below 1 Ω
      1G-4 (GND2) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - ENGINE ROOM 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
      1G-2 (TAIL) - 3D-9 Always Below 1 Ω
      3D-9 - Body ground Always 10 kΩ or higher
      1F-13 (FOGS) - 3D-38 Always Below 1 Ω
      3D-38 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. Remove the instrument panel junction block assembly Click here.

    2. A000886E04
      A0006V4E04

      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
      MB-13 (FFGO) - 3D-38 Always Below 1 Ω
      3D-38 - Body ground Always 10 kΩ or higher

    4. Connect a positive (+) lead from the auxiliary battery to terminal 3E-1.

    5. Connect a negative (-) lead from the auxiliary battery to terminal MB-14 (TRLY).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      3D-9 - Body ground Always 11 to 14 V
      Text in Illustration
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK

  7. CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - FOG LIGHT ASSEMBLY)


    1. Disconnect the 1F engine room junction block assembly connector.

    2. Disconnect the A5 fog light assembly LH connector.

    3. Disconnect the A48 fog light assembly RH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1F-1 (FOGR) - A5-2 Always Below 1 Ω
      1F-1 (FOGR) - A48-2 Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK ENGINE ROOM JUNCTION BLOCK ASSEMBLY


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

    2. Check that the fog lights operate normally.

      OK
      The fog lights operate normally.

    OK

    END (ENGINE ROOM JUNCTION BLOCK ASSEMBLY WAS DEFECTIVE)

    NG

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