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On-Vehicle Inspection [09/2023 - ]: Procedure

WARNING: This page is about a different car, the 2024 Lexus TX 550h+ and 2024 Lexus TX 500h. However, it is still accessible from the selected car via links, so may be relevant.
  1. WARNING LIGHT AND INDICATOR LIGHT INITIAL CHECK 
    1. When the ignition switch is turned to ON, check that the ABS warning light, brake system warning light (red indicator), brake system warning light (yellow indicator), VSC OFF indicator light, slip indicator light, brake hold standby indicator light and brake hold operated indicator light come on for approximately 3 seconds.

      HINT: 

      • When the brake fluid level is low, the brake system warning light (red indicator) comes on.
      • If the skid control ECU stores any DTCs, the ABS warning light, brake system warning light (red indicator), brake system warning light (yellow indicator) and slip indicator light will come on. Also, in this state, if the vehicle is under the following conditions and the brake hold switch (electric parking brake switch assembly) is turned on, the brake hold operated indicator light blinks.
        1. Vehicle Conditions:
          1. The driver door is closed.
          2. The driver seat belt is fastened.
      • If the warning lights and indicator lights do not illuminate or illuminate for more than approximately 3 seconds, perform troubleshooting for the electronically controlled brake system.

        Refer to HOW TO PROCEED WITH TROUBLESHOOTING [09/2023 - 12/2023] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2023 - ]

  2. INSPECT BRAKE FLUID LEVEL WARNING SWITCH 

    Pre-procedure1

    • Remove the brake master cylinder reservoir filler cap assembly.
    • Disconnect the brake fluid level warning switch (brake master cylinder reservoir assembly) connector.
    • Measure the resistance according to the value(s) in the table below.
      GTY1240455Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component without harness connected
      (Brake Fluid Level Warning Switch (Brake Master Cylinder Reservoir Assembly))

      HINT: 

      A float is located inside the brake master cylinder reservoir assembly. Its position changes according to the level of brake fluid.

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      B1-1 (+) - B1-2 (E) Brake fluid level warning switch (brake master cylinder reservoir assembly) off (float up) 1.84 to 2.16 kΩ kΩ
      B1-1 (+) - B1-2 (E) Brake fluid level warning switch (brake master cylinder reservoir assembly) on (float down) Below 1 Ω Ω

    Post-procedure1

    • If there are no problems after completing the preceding inspection, adjust the brake fluid to the MAX level with the ignition switch turned to ON.
  3. BRAKE SYSTEM ON-VEHICLE INSPECTION 

    If no DTCs are output but the problem still occurs, use the following procedure to inspect the pressure sensor, brake booster with master cylinder assembly and stroke simulator.

    NOTE:

    DTCs may be stored during the inspection procedure. Be sure to clear the DTCs and check that no DTCs are output after the inspection is finished.

    1. INSPECT PRESSURE SENSOR
      1. Check the auxiliary battery voltage.

        Standard Voltage

        Tester Connection Condition Specified Condition Result
        Auxiliary battery Ignition switch off 11 to 14 V V
      2. Set a pedal effort gauge and SST.
        GTY1237887Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        *a Pedal Effort Gauge *b SST (LSPV Gauge)
        *c SST (No. 1 Nipple) *d SST (No. 3 Nipple)

        HINT: 

        Simultaneously measure the brake fluid pressure of all 4 wheels, or 2 wheels at a time.

        (1) Set a pedal effort gauge and SST.

        • SST: 09709-29018 
          1. 09709-00060

        (2) Park (P) selected and parking brake applied.

        (3) Bleed air from SST (LSPV gauge).

        HINT: 

        Refer to BLEEDING [09/2023 - ]

      3. Inspect the master cylinder sensor 1, gap hold chamber oil pressure and servo pressure.

        (1) Check the value output from "Master Cylinder Sensor 1", "Gap Hold Chamber Oil Pressure" and "Servo Pressure" by depressing the brake pedal.

        Chassis > Brake Booster > Data List 

        Tester Display
        Servo Pressure
        Gap Hold Chamber Oil Pressure

        Chassis > Brake/EPB > Data List 

        Tester Display
        Master Cylinder Sensor 1

        Standard Result

        Pedal Effort Gap Hold Chamber Oil Pressure Servo Pressure Master Cylinder Sensor 1 Front Wheels Hydraulic Pressure Rear Wheels Hydraulic Pressure
        50 N (5 kgf, 11.2 lbf) 0.00 to 0.76 MPa 1.21 to 6.71 MPa 0.91 to 6.41 MPa 0.91 to 6.41 MPa (9.28 to 65.36 kgf/cm2 , 132 to 929 psi) 1.21 to 6.71 MPa (12.34 to 68.42 kgf/cm2 , 175 to 973 psi)
        100 N (10 kgf, 22.5 lbf) 0.62 to 1.42 MPa 5.45 to 10.95 MPa 5.15 to 10.65 MPa 5.15 to 10.65 MPa (52.52 to 108.60 kgf/cm2 , 747 to 1544 psi) 5.45 to 10.95 MPa (55.57 to 111.66 kgf/cm2 , 790 to 1588 psi)
        150 N (15 kgf, 33.7 lbf) 1.30 to 2.10 MPa 7.10 to 12.60 MPa 6.80 to 12.30 MPa 6.80 to 12.30 MPa (69.34 to 125.43 kgf/cm2 , 986 to 1784 psi) 7.10 to 12.60 MPa (72.40 to 128.48 kgf/cm2 , 1030 to 1827 psi)
        200 N (20 kgf, 45.0 lbf) 1.98 to 2.78 MPa 7.10 to 12.60 MPa 6.80 to 12.30 MPa 6.80 to 12.30 MPa (69.34 to 125.43 kgf/cm2 , 986 to 1784 psi) 7.10 to 12.60 MPa (72.40 to 128.48 kgf/cm2 , 1030 to 1827 psi)
      4. Remove the pedal effort gauge and SST.

        (1) Remove the pedal effort gauge and SST, and bleed the brake line.

        HINT: 

        Refer to BLEEDING [09/2023 - ]

    2. INSPECT BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY
      1. Check the auxiliary battery voltage.

        Standard Voltage

        Tester Connection Condition Specified Condition Result
        Auxiliary battery Ignition switch off 11 to 14 V V
      2. Set a pedal effort gauge and SST.
        GTY1237887Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        *a Pedal Effort Gauge *b SST (LSPV Gauge)
        *c SST (No. 1 Nipple) *d SST (No. 3 Nipple)

        HINT: 

        Simultaneously measure the brake fluid pressure of all 4 wheels, or 2 wheels at a time.

        (1) Set a pedal effort gauge and SST.

        • SST: 09709-29018 
          1. 09709-00060

        (2) Park (P) selected and parking brake applied.

        (3) Clear the DTCs.

        Chassis > Brake Booster > Clear DTCs 

        Chassis > Brake/EPB > Clear DTCs 

        (4) Bleed air from SST (LSPV gauge).

        HINT: 

        Refer to BLEEDING [09/2023 - ]

      3. Check operation without brake boost.

        (1) Inspect and adjust the brake pedal height.

        (2) Adjust the brake fluid level of the reservoir so that it is between the MIN line and MAX line.

        GTY1123132Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        *a MAX Line
        *b MIN Line

        (3) Select "Motor Deactivate" on the "ECB Utility" screen.

        Chassis > Brake/EPB > Utility 

        Tester Display
        ECB Utility

        (4) Perform "Motor Deactivate" according to the display on the GTS.

        (5) Depress the brake pedal 10 times or more.

        (6) Check that the brake pedal is firm.

        (7) Check the values output from "Stroke Sensor" and "Stroke Sensor2" by depressing the brake pedal.

        Chassis > Brake Booster > Data List 

        Tester Display
        Stroke Sensor

        Chassis > Brake/EPB > Data List 

        Tester Display
        Stroke Sensor2

        Standard Result

        Pedal Effort Stroke Sensor Stroke Sensor2 Front Left Wheel Hydraulic Pressure Front Right Wheel Hydraulic Pressure
        200 N (20 kgf, 45.0 lbf) 1.09 to 1.79 V 3.21 to 3.91 V 0.00 to 3.22 MPa (0.00 to 32.83 kgf/cm2 , 0 to 467 psi) 0.00 to 3.22 MPa (0.00 to 32.83 kgf/cm2 , 0 to 467 psi)
        500 N (51 kgf, 112.4 lbf) 1.47 to 2.17 V 2.83 to 3.53 V 2.43 to 6.43 MPa (24.78 to 65.57 kgf/cm2 , 352 to 932 psi) 2.43 to 6.43 MPa (24.78 to 65.57 kgf/cm2 , 352 to 932 psi)

        HINT: 

        Check the performance of the brake booster with master cylinder assembly by comparing the pedal force with the value of the LSPV gauge and each stroke sensor. If there is a problem, determine the state of the brake booster with master cylinder assembly by using these results together with the results from inspecting the brake pedal stroke sensor.

        (8) Remove the pedal effort gauge and SST, and bleed the brake system.

        HINT: 

        Refer to BLEEDING [09/2023 - ]

    3. INSPECT STROKE SIMULATOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY)
      1. Check the auxiliary battery voltage.

        Standard Voltage

        Tester Connection Condition Specified Condition Result
        Auxiliary battery Ignition switch off 11 to 14 V V
      2. Set a pedal effort gauge.

        (1) Set a pedal effort gauge.

        (2) Park (P) selected and parking brake applied.

        (3) Clear the DTCs.

        Chassis > Brake Booster > Clear DTCs 

        Chassis > Brake/EPB > Clear DTCs 

      3. Check operation with brake boost.

        (1) Depress the brake pedal 4 or 5 times.

        (2) Check the values output from "Stroke Sensor" and "Stroke Sensor2" by depressing the brake pedal.

        Chassis > Brake Booster > Data List 

        Tester Display
        Stroke Sensor

        Chassis > Brake/EPB > Data List 

        Tester Display
        Stroke Sensor2

        Standard Voltage

        Pedal Effort Stroke Sensor Stroke Sensor2
        50 N (5 kgf, 11.2 lbf) 1.27 to 1.97 V 3.03 to 3.73 V
        100 N (10 kgf, 22.5 lbf) 1.60 to 2.30 V 2.70 to 3.40 V
        150 N (15 kgf, 33.7 lbf) 1.79 to 2.49 V 2.51 to 3.21 V
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