LIGHTING SYSTEM Rear Fog Light Circuit

DESCRIPTION

The main body ECU (network gateway ECU) receives headlight dimmer switch assembly information signals, and illuminates the rear fog light.

WIRING DIAGRAM

A004JUFE02

CAUTION / NOTICE / HINT

Tech Tips

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

PROCEDURE


  1. CHECK OPERATION (TAILLIGHT)


    1. Check the operation of the taillight.

      OK
      The taillight operates normally.

    NG

    GO TO TAILLIGHT Click here

    OK

  2. PERFORM ACTIVE TEST USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    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
      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).

    OK

    REPLACE MAIN BODY ECU (NETWORK GATEWAY ECU) Click here

    NG

  3. INSPECT RR FOG RELAY


    1. Remove the RR FOG relay from the engine room relay block.

    2. Inspect the RR FOG relay Click here.


    NG

    REPLACE RR FOG RELAY

    OK

  4. INSPECT REAR FOG LIGHT BULB (REAR LIGHT ASSEMBLY)


    1. Remove the rear fog light bulb Click here.

    2. Inspect the rear fog light bulb Click here.


    NG

    REPLACE REAR FOG LIGHT BULB Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (BATTERY - RR FOG RELAY)


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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      Relay terminal 2 - Body ground Light control switch off → tail Below 1 V → 11 to 14 V
      Relay terminal 5 - Body ground Always 11 to 14 V

    NG

    INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (RR FOG RELAY - REAR LIGHT ASSEMBLY)


    1. Disconnect the H2 rear light assembly connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      Relay terminal 3 - H2-2 Light control switch off → tail Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      Relay terminal 3 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK HARNESS AND CONNECTOR (RR FOG RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the A73 instrument panel junction block assembly connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      Relay terminal 1 - A73-3 Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      Relay terminal 1 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


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

    2. Remove the main body ECU (network gateway ECU) from the instrument panel junction block assembly.

      A004H39E02
      Text in Illustration
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      		 - -

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      3C-26 - Battery negative (-) terminal

      Connect a positive (+) lead from the battery → 3E-1

      Connect a negative (-) lead from the battery → MB-7 (TRLY)

      		 11 to 14 V

    OK

    REPLACE MAIN BODY ECU (NETWORK GATEWAY ECU) Click here

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here