Front Fog Light Circuit [03/2017 - ]: Procedure

2018 Toyota 86 GT, Standard TransSECTION Procedure
  1. PERFORM ACTIVE TEST USING TECHSTREAM (FR FOG LIGHT RELAY) 
    1. Connect the Techstream to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the Techstream 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).

      Result

      Result Proceed to
      NG A
      OK B

    Result: 

    REPLACE MAIN BODY ECU (NETWORK GATEWAY ECU). Refer to  REMOVAL [06/2016 - ] 

    Result: 

    See step  2

  2. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 
    1. Remove the instrument panel junction block assembly.

      Refer to REMOVAL [06/2016 - ]

    2. Remove the main body ECU (network gateway ECU) from the instrument panel junction block assembly.
    3. Measure the voltage according to the value(s) in the table below.
      GTY716520Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Component without harness connected
      (Instrument Panel Junction Block Assembly)
      - -

      Standard Voltage

      Tester Connection Condition Specified Condition
      MB-30 (FFGO) - 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
      3C-3 - Battery negative (-) terminal Connect a positive (+) lead from the battery → 3E-1
      Connect a negative (-) lead from the battery → MB-7 (TRLY), MB-30 (FFGO)
      11 to 14 V
      3C-5 - Battery negative (-) terminal Connect a positive (+) lead from the battery → 3E-1
      Connect a negative (-) lead from the battery → MB-7 (TRLY), MB-30 (FFGO)
      11 to 14 V

    Result: 

    OK 

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [03/2017 - ] 

    Result: 

    NG 

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to  REMOVAL [06/2016 - ] 

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.