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Inspection Procedure

NOTE: When replacing the master cylinder solenoid, perform zero point calibration (See CALIBRATION  ).
  1. CHECK STOP LIGHT SWITCH OPERATION 
    1. Check that the stop light comes on when the brake pedal is depressed, and goes off when the brake pedal is released.

      OK: Stop light switch function is normal. 

      HINT:

      Check the stop light bulb as it may have burned out.

    NG: GO TO LIGHTING SYSTEM (STOP LIGHT CIRCUIT)  (See STOP LIGHT CIRCUIT )

    OK: Go to Next Step 

  2. INSPECT SKID CONTROL ECU (STP TERMINAL) 
    1. Disconnect the A24 skid control ECU connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      A24-7 (STP) - Body ground Stop light switch on (Brake pedal depressed) 8 to 14 V
      A24-7 (STP) - Body ground Stop light switch off (Brake pedal released) Below 1.5 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 1: Identifying A24 Skid Control ECU Connector
    G05629911Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  3. INSPECT SKID CONTROL ECU (STP2 TERMINAL) 
    1. Measure the voltage according to the value(s) in the table below.

      Standard Voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      A24-45 (STP2) - Body ground Stop light switch on (Brake pedal depressed) 8 to 14 V
      A24-45 (STP2) - Body ground Stop light switch off (Brake pedal released) Below 1.5 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 2: Identifying Skid Control ECU (STP2 Terminal)
    G05629912Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  4. PERFORM ACTIVE TEST USING TECHSTREAM (STOP LIGHT RELAY) 
    1. Reconnect the A24 skid control ECU connector.
    2. Connect the Techstream to the DLC3.
    3. Turn the engine switch on (IG) and turn the Techstream on.
    4. Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test.

      ABS/VSC/TRAC 

      ACTIVE LIST - ABS/VSC/TRAC

      Item Test Part Control Range Diagnostic Note
      Stop Light Relay BRK LP relay Relay ON/OFF Observe the rear combination light (Does not come on for 5 seconds or more).
    5. Check that "ON" and "OFF" of the stop light can be shown on the rear combination light by the Techstream.

      OK: The stop light turns on or off in accordance with the Techstream. 

    NG:  Go to step  6

    OK: Go to Next Step 

  5. RECONFIRM DTC 
    1. Clear the DTC (See DTC CHECK/CLEAR  ).
    2. Check if the same DTC is output (See DTC CHECK/CLEAR  ).

      HINT:

      Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

    Result 

    RESULT REFERENCE

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

    B: USE SIMULATION METHOD TO CHECK  (See HOW TO PROCEED WITH TROUBLESHOOTING )

    A: REPLACE MASTER CYLINDER SOLENOID  (See DISASSEMBLY )

  6. INSPECT BRK LP RELAY (POWER SOURCE TERMINAL) 
    1. Remove the BRK LP relay.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      1 - Body ground Engine switch on (IG) 8 to 14 V
      5 - Body ground Always 11 to 14 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 3: Identifying BRK LP Relay
    G05629913Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  7. INSPECT BRK LP RELAY 
    1. Measure the resistance according to the value(s) in the table below.
    Fig 4: Inspecting BRK LP Relay
    G05629914Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    Standard Resistance 

    STANDARD RESISTANCE SPECIFICATION

    Tester Connection Condition Specified Condition
    3 - 4 When battery positive voltage is applied to terminal 1 and battery negative voltage is applied to terminal 2 10 kΩ or higher
    When battery positive voltage is not applied to terminal 1 and battery negative voltage is not applied to terminal 2 Below 1 Ω
    3 - 5 When battery positive voltage is applied to terminal 1 and battery negative voltage is applied to terminal 2 Below 1 Ω
    When battery positive voltage is not applied to terminal 1 and battery negative voltage is not applied to terminal 2 10 kΩ or higher

    NG: REPLACE BRK LP RELAY 

    OK: Go to Next Step 

  8. INSPECT SKID CONTROL ECU (STPO TERMINAL) 
    1. Install the BRK LP relay.
    2. Disconnect the A24 skid control ECU connector.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      S37-16 (STPO) - Body ground Engine switch on (IG) 11 to 14 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 5: Identifying Skid Control ECU (STPO Terminal)
    G05629915Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  9. RECONFIRM DTC 
    1. Clear the DTC (See DTC CHECK/CLEAR  ).
    2. Check if the same DTC is output (See DTC CHECK/CLEAR  ).

      HINT:

      Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

      Result 

      RESULT REFERENCE

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

    B: USE SIMULATION METHOD TO CHECK  (See HOW TO PROCEED WITH TROUBLESHOOTING )

    A: REPLACE MASTER CYLINDER SOLENOID  (See DISASSEMBLY )

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