LIGHTING SYSTEM Rear Fog Light Circuit

DESCRIPTION

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

WIRING DIAGRAM

B000K6CE01

INSPECTION PROCEDURE

Note

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

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 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. Check that the relay operates.

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

    NG

    CHECK ENGINE ROOM JUNCTION BLOCK ASSEMBLY Click here

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

  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) Click here


    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-10 (RFGS) - 3D-35 Always Below 1 Ω
      3D-35 - 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. B000HKAE09
      Text in Illustration
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      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-27 (RFGO) - 3D-35 Always Below 1 Ω
      3D-35 - Body ground Always 10 kΩ or higher

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

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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      3D-9 - Battery negative Always 11 to 14 V

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK

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


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

    2. Disconnect the T1 and T7 rear light assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1F-12 - T7-4 Always Below 1 Ω
      1F-12 - T1-4 Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (REAR LIGHT ASSEMBLY - BODY GROUND)


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

      Standard Resistance
      Tester Connection Condition Specified Condition
      T7-3 - Body ground Always Below 1 Ω
      T1-3 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. 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 fog lights operate normally.

      OK
      The fog lights operate normally.

    NG

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

    OK

    END (ENGINE ROOM JUNCTION BLOCK ASSEMBLY WAS DEFECTIVE)