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Home >> Lexus >> 2019 >> LC 500 >> Repair and Diagnosis >> Brakes >> Mechanical - Hydraulic >> Electronically Controlled Brake System - Diagnostic Codes (Coupe) (4 Of 4) & Symptom Tests >> Electronically Controlled Brake System >> VSC OFF Switch Circuit [05/2023 - ] >> Procedure

VSC OFF Switch Circuit [05/2023 - ]: Procedure

  1. CHECK CAN COMMUNICATION SYSTEM 
    1. Check if CAN communication system DTCs are output.

      Refer to DIAGNOSIS SYSTEM [05/2023 - ]

      Result

      Result Proceed to
      DTCs are not output. A
      DTCs are output. B

    Result: 

    INSPECT CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [05/2023 - ] 

    Result: 

    See step  2

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

      OK

      The connector is securely connected.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    CONNECT CONNECTOR TO SKID CONTROL ECU ASSEMBLY CORRECTLY 

    Result: 

    OK 

    See step  3

  3. READ VALUE USING TECHSTREAM (TRAC/VSC OFF MODE) 
    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 [05/2023 - ]

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      TRAC/VSC Off Mode TRAC/VSC off mode Normal, TRAC OFF or VSC OFF Normal: Normal mode
      TRAC OFF: TRAC off mode
      VSC OFF: VSC off mode
      -

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display
      TRAC/VSC Off Mode
    4. Check the indicator light and mode condition on the Techstream changes according to VSC OFF switch (No. 2 combination switch assembly) operation.

      OK

      Switch Operation Mode Condition Display Multi-information Display (TRAC OFF Message) VSC OFF Indicator Light
      Not pressed Normal Not displayed Does not come on
      Pressing the VSC OFF switch (No. 2 combination switch assembly) TRAC OFF Displayed Does not come on
      Pressing and holding the VSC OFF switch (No. 2 combination switch assembly) VSC OFF Displayed Comes on

      Result

      Result Proceed to
      Indicator light and mode condition display do not change. A
      Mode condition display is normal, but indicator light does not change. B
      Indicator light and mode condition display is normal. C

    Result: 

    INSPECT METER / GAUGE SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [03/2017 - ] 

    Result: 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [05/2023 - ] 

    Result: 

    See step  4

  4. PERFORM ACTIVE TEST USING TECHSTREAM (MULTI-INFORMATION DISPLAY (TRAC OFF MESSAGE) AND VSC OFF INDICATOR LIGHT) 
    1. Select the Active Test on the Techstream.

      Refer to DATA LIST / ACTIVE TEST [05/2023 - ]

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      TRC(TRAC) OFF Indicator Light Multi-information display (TRAC OFF message) Display ON/OFF Observe combination meter assembly
      VSC OFF Indicator Light VSC OFF indicator light Indicator light ON/ OFF Observe combination meter assembly

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display
      TRC(TRAC) OFF Indicator Light

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display
      VSC OFF Indicator Light
    2. Check the multi-information display (TRAC OFF message) and VSC OFF indicator light on the combination meter assembly turns ON or OFF in accordance with the Techstream operation.

      OK

      The multi-information display (TRAC OFF message) and VSC OFF indicator light turns ON or OFF in accordance with the Techstream operation.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  7

    Result: 

    OK 

    See step  5

  5. INSPECT VSC OFF SWITCH (NO. 2 COMBINATION SWITCH ASSEMBLY) 
    1. Turn the engine switch off.
      GTY837526Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component without harness connected
      (VSC OFF Switch (No. 2 Combination Switch Assembly))
    2. Disconnect the P52 VSC OFF switch (No. 2 combination switch assembly) connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      8 (+) - 1 (E) Switch pushed Below 1 Ω
      8 (+) - 1 (E) Switch not pushed 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE COMBINATION SWITCH ASSEMBLY. Refer to  REMOVAL [03/2017 - ] 

    Result: 

    OK 

    See step  6

  6. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU ASSEMBLY - VSC OFF SWITCH (NO. 2 COMBINATION SWITCH ASSEMBLY)) 
    1. Disconnect the A9 skid control ECU assembly connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A9-19 (CSW) - P52-8 (+) Always Below 1 Ω
      A9-19 (CSW) or P52-8 (+) - Body ground Always 10 kΩ or higher
      P52-1 (E) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE SKID CONTROL ECU ASSEMBLY. Refer to  REMOVAL [05/2023 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  7. INSPECT COMBINATION METER ASSEMBLY 
    1. Turn the engine switch off.
    2. Perform the Active Test of the combination meter assembly (meter CPU) using the Techstream.

      Refer to DATA LIST / ACTIVE TEST [03/2017 - ]

      Body Electrical > Combination Meter > Active Test 

      Tester Display
      Meter Display 1

      Body Electrical > Combination Meter > Active Test 

      Tester Display
      Indicat. VSC OFF
    3. Check the combination meter assembly.

      OK

      The multi-information display and VSC OFF indicator light turns on or off in accordance with the Techstream operation.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE SKID CONTROL ECU ASSEMBLY. Refer to  REMOVAL [05/2023 - ] 

    Result: 

    NG 

    INSPECT METER / GAUGE SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [03/2017 - ]