2012 Lexus IS 250C Automatic TransFACTORY OEM SERVICE PROCEDURE

VSC OFF Indicator Light Remains ON: Procedure

  1. CHECK CAN COMMUNICATION SYSTEM 
    1. Check if a CAN communication system DTC is output. Refer to DIAGNOSIS SYSTEM .

      Result

      Result Proceed to
      DTC is not output A
      DTC is output B

    B → See step   12 

    A: Go to next step 

  2. CHECK MULTIPLEX COMMUNICATION SYSTEM 
    1. Check if a multiplex communication system DTC is output. Refer to DTC CHECK / CLEAR .

      Result

      Result Proceed to
      DTC is not output A
      DTC is output B

    B → See step   15 

    A: Go to next step 

  3. CHECK IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED 
    1. Check if the skid control ECU connector is securely connected.

      OK

      The connector is securely connected.

    NG → CONNECT CONNECTOR TO ECU CORRECTLY 

    OK: Go to next step 

  4. CHECK BATTERY 
    1. Check the battery voltage.

      Standard Voltage

      11 to 14 V

      Result

      Result Proceed to
      OK A
      NG (for 2GR-FSE) B
      NG (for 4GR-FSE) C

    B → See step   11 

    C → See step   14 

    A: Go to next step 

  5. READ VALUE USING TECHSTREAM (VSC OFF SWITCH) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Select the Data List on the Techstream. Refer to DATA LIST / ACTIVE TEST .
      ABS/VSC/TRAC

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      TRC/VSC Off Mode VSC OFF switch / NORMAL, TRC OFF or VSC OFF NORMAL: Normal
      TRC OFF: TR(A)C off mode
      VSC OFF: VSC off mode
      -
    4. Using the Techstream, check the switch condition on the Techstream changes according to VSC OFF switch operation.

      OK

      The Techstream display changes according to VSC OFF switch operation.

    NG → See step   7 

    OK: Go to next step 

  6. INSPECT COMBINATION METER ASSEMBLY 
    1. Turn the engine switch off.
    2. Perform the Active Test of the combination meter (meter CPU) using the Techstream. Refer to DATA LIST / ACTIVE TEST .
    3. Check the combination meter.

      OK

      The VSC OFF indicator light turns on or off in accordance with the Techstream operation.

      HINT: 

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing the part. Refer to PROBLEM SYMPTOMS TABLE .

    NG → See step   10 

    OK → See step   9 

  7. INSPECT VSC OFF SWITCH 
    1. Turn the engine switch off.
      Fig 1: VSC Off Switch Connector End View
      GTY393680Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the VSC OFF switch connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      3 (+) - 4 (E) Switch is pushed in Below 25 Ω
      3 (+) - 4 (E) Switch is not pushed in 10 kΩ or higher
      TEXT IN ILLUSTRATION

      *1 Component without harness connected
      (VSC OFF Switch)

    NG → See step   13 

    OK: Go to next step 

  8. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - VSC OFF SWITCH) 
    1. Disconnect the skid control ECU connector.
      Fig 2: A58 & J37 Connectors
      GTY394356Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A58-30 (CSW) - J37-3 (+) Always Below 1 Ω
      A58-30 (CSW) - Body ground Always 10 kΩ or higher
      J37-4 (E) - Body ground Always Below 1 Ω
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Skid Control ECU)
      *2 Front view of wire harness connector
      (to VSC OFF Switch)

      HINT: 

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step. Refer to PROBLEM SYMPTOMS TABLE .

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   9 

  9. REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL 
  10. REPLACE COMBINATION METER ASSEMBLY. Refer to  REMOVAL 
  11. CHECK OR REPLACE CHARGING SYSTEM OR BATTERY (for 2GR-FSE). Refer to  ON-VEHICLE INSPECTION 
  12. INSPECT CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING 
  13. REPLACE VSC OFF SWITCH. Refer to  REMOVAL 
  14. CHECK OR REPLACE CHARGING SYSTEM OR BATTERY (for 4GR-FSE). Refer to  ON-VEHICLE INSPECTION 
  15. INSPECT MULTIPLEX COMMUNICATION SYSTEM. Refer to  DIAGNOSTIC TROUBLE CODE CHART 
Factory Service Tools

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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.

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