LEMON Manuals: Even more car manuals for everyone
Home >> Toyota >> 2021 >> Mirai Limited >> Repair and Diagnosis >> Brakes >> Mechanical - Hydraulic >> Electronically Controlled Brake System - Diagnostic Codes (3 Of 4) >> Electronically Controlled Brake System >> DTC C1400-00: Brake Pressure Leak Malfunction; DTC C140A-00: Pressure Control Reservoir Leak Malfunction [11/2020 - ] >> Procedure

DTC C1400-00: Brake Pressure Leak Malfunction; DTC C140A-00: Pressure Control Reservoir Leak Malfunction [11/2020 - ]: Procedure

  1. INSPECT WHEEL CYLINDER PRESSURE 

    Pre-procedure1

    • Mount a pedal effort gauge.
    • Disconnect the A39 brake booster pump assembly connector.
    • Depress the brake pedal 10 times or more until it becomes hard.

      HINT: 

      Depressing the brake pedal with the connector of the brake booster pump assembly disconnected drops the accumulator pressure to approximately 0 MPa.

    • Connect an LSPV gauge set.
    • Slowly depress the brake pedal and check the wheel cylinder pressure with respect to brake pedal depression force.
      NOTE:

      Check the wheel cylinder pressure with the switching solenoid (SSA, SGH) off and an accumulator pressure of 0 MPa.

      Standard Hydraulic Pressure

      FOR FRONT RIGHT WHEEL

      Brake Effort
      [N (kgf, lbf)]
      Specified Condition
      200 (20.4, 45.0) 0.00 to 2.86 (0.0 to 29.2, 0 to 415)
      500 (51.0, 112.4) 1.16 to 5.16 (11.8 to 52.6, 168 to 748)
      FOR REAR RIGHT WHEEL

      Brake Effort
      [N (kgf, lbf)]
      Specified Condition
      200 (20.4, 45.0) 0.00 to 2.86 (0.0 to 29.2, 0 to 415)
      500 (51.0, 112.4) 1.16 to 5.16 (11.8 to 52.6, 168 to 748)

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • None

    Result: 

    NG 

    See step  5

    Result: 

    OK 

    See step  2

  2. CLEAR DTC 

    Pre-procedure1

    • None
    • Clear the DTCs.

      Chassis > Brake/EPB > Clear DTCs 

      Result

      Proceed to
      NEXT

    Post-procedure1

    • Turn the ignition switch off.

    Result: 

    NEXT 

    See step  3

  3. RECONFIRM DTC 

    Pre-procedure1

    • Based on the Freeze Frame Data and interview with the customer, attempt to reproduce the conditions when the malfunction occurred.
    • Check if the same DTC is output.

      Chassis > Brake/EPB > Trouble Codes 

      Result

      Result Proceed to
      C1400-00 and C140A-00 are not output A
      C1400-00 or C140A-00 is output B
      Only C140A-00 is output C

    Post-procedure1

    • None

    Result: 

    A 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2020 - ] 

    Result: 

    B 

    REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [11/2020 - 11/2021]  , or refer to  REMOVAL [11/2021 - 12/2022]  , or refer to  REMOVAL [12/2022 - 12/2023]  , or refer to  REMOVAL [12/2023 - ] 

    Result: 

    C 

    See step  4

  4. RECONFIRM DTC 
    1. Check the DTCs that are output.

      Chassis > Brake Booster > Trouble Codes 

      Result

      Result Proceed to
      C139A-00 is output A
      DTCs are not output B

    Result: 

    A 

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY AND BRAKE ACTUATOR ASSEMBLY 

    For Brake Booster with Master Cylinder Assembly: Refer to REMOVAL [11/2020 - 11/2021] , or refer to REMOVAL [11/2021 - 12/2022] , or refer to REMOVAL [12/2022 - 12/2023] , or refer to REMOVAL [12/2023 - ]

    For Brake Actuator Assembly: Refer to REMOVAL [11/2020 - 11/2021] , or refer to REMOVAL [11/2021 - 12/2022] , or refer to REMOVAL [12/2022 - 12/2023] , or refer to REMOVAL [12/2023 - ]

    Result: 

    B 

    REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [11/2020 - 11/2021]  , or refer to  REMOVAL [11/2021 - 12/2022]  , or refer to  REMOVAL [12/2022 - 12/2023]  , or refer to  REMOVAL [12/2023 - ] 

  5. INSPECT BRAKE FLUID LEAKS 
    1. Brake fluid leaks and air in brake line inspection
      1. Check and take a note of the fluid level in the brake master cylinder reservoir assembly (brake booster with master cylinder assembly).
      2. Repeatedly depress the brake pedal and confirm that the brake pedal feels normal (no air in the system, etc.).
      3. Check if the brake fluid level in the brake master cylinder reservoir assembly (brake booster with master cylinder assembly) has changed.
      4. If the brake fluid level has decreased, check for leaks due to damaged brake lines or hoses, loose union nuts, damaged brake master cylinder assembly seals, etc.

      OK

      There are no brake fluid leaks and no air in the system.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [11/2020 - 11/2021]  , or refer to  REMOVAL [11/2021 - 12/2022]  , or refer to  REMOVAL [12/2022 - 12/2023]  , or refer to  REMOVAL [12/2023 - ] 

    Result: 

    NG 

    REPAIR BRAKE FLUID LEAKS AND ADD FLUID