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Home >> Lexus >> 2020 >> UX 200 Luxury >> Repair and Diagnosis >> External Pages >> Different car >> Section 9 (Electronically Controlled Brake System (Diagnostic Codes (4 Of 4) & Circuit Tests) (Hybrid)) >> ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model) >> DTC C14B6: Stroke Sensor / Reaction Force Pressure Sensor Output Inconsistent [10/2018 - ] >> Procedure

DTC C14B6: Stroke Sensor / Reaction Force Pressure Sensor Output Inconsistent [10/2018 - ]: Procedure

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  1. CUSTOMER PROBLEM ANALYSIS (CHECK CONDITION WHEN MALFUNCTION OCCURRED) AND FREEZE FRAME DATA 
    1. Interview the customer to check the vehicle conditions when the brake warning light / yellow (minor malfunction) illuminated.
    2. Using the Techstream, read the "Shift Lever Position", "Vehicle Speed", "Yaw Rate Sensor", "Steering Sensor", "Stop Light SW", "Stroke Sensor", "Reaction Force Pressure", "Servo Pressure" and "Accumulator Pressure" of the Freeze Frame Data stored when the DTC was stored.

      HINT: 

      • Freeze Frame Data is only stored once when a DTC is stored.
      • If other DTCs are output, repair any malfunctions related to those DTCs first, and then reproduce the conditions that caused DTC C14B6 to be stored based on the interview with the customer.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  2

  2. INSPECT BRAKE PEDAL STROKE SENSOR ASSEMBLY OUTPUT VOLTAGES AND WHEEL CYLINDER PRESSURE 
    1. Turn the power switch off.
    2. Mount a pedal effort gauge.
    3. Disconnect the A11 brake booster pump assembly connector.
    4. 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.

    5. Connect an LSPV gauge set.
    6. Select the Data List on the Techstream.

      Refer to DATA LIST / ACTIVE TEST [10/2018 - ]

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stroke Sensor Brake pedal stroke sensor Min.: 0.00 V, Max.: 5.00 V Brake pedal released: 0.65 to 1.35 V Reading increases when brake pedal is depressed

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display
      Stroke Sensor
    7. Slowly depress the brake pedal and check the brake pedal stroke sensor assembly output voltages and 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 Pressure

      FOR FRONT RIGHT WHEEL

      Brake Effort
      [N (kgf, lbf)]
      Stroke Sensor
      [V]
      Hydraulic Pressure
      [MPa (kgf/cm2 , psi)]
      200 (20, 45.0) 1.16 to 1.91 0.03 (0.3, 4.4) to 2.03 (20.7, 294)
      500 (51, 112.4) 1.35 to 2.09 2.05 (20.9, 297) to 4.06 (41.4, 589)
      FOR FRONT LEFT WHEEL

      Brake Effort
      [N (kgf, lbf)]
      Stroke Sensor
      [V]
      Hydraulic Pressure
      [MPa (kgf/cm2 , psi)]
      200 (20, 45.0) 1.16 to 1.91 0.03 (0.3, 4.4) to 2.03 (20.7, 294)
      500 (51, 112.4) 1.35 to 2.09 2.05 (20.9, 297) to 4.06 (41.4, 589)

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022]  , or refer to  REMOVAL [07/2022 - ] 

    Result: 

    NG 

    See step  3

  3. REPLACE BRAKE PEDAL STROKE SENSOR ASSEMBLY 
    1. Turn the power switch off.
    2. Reconnect the A11 brake booster pump assembly connector.
    3. Replace brake pedal stroke sensor assembly.

      Refer to REMOVAL [10/2018 - 07/2022] , or refer to REMOVAL [07/2022 - ]

    4. Perform zero point calibration of the brake pedal stroke sensor assembly.

      Refer to INITIALIZATION [10/2018 - ]

      Chassis > ABS/VSC/TRAC > Utility 

      Tester Display
      ECB Utility

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  4

  4. RECONFIRM DTC 
    1. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [10/2018 - ]

      Chassis > ABS/VSC/TRAC > Clear DTCs 

    2. Perform a road test under the same malfunction conditions recreated based on the Freeze Frame Data or customer problem analysis.
    3. Turn the power switch off and wait for 2 minutes or more.
    4. Turn the power switch on (IG).
    5. Check if the same DTC is output.

      Refer to DTC CHECK / CLEAR [10/2018 - ]

      Chassis > ABS/VSC/TRAC > Trouble Codes 

      Result

      Result Proceed to
      DTC C14B6 is not output. A
      DTC C14B6 is output. B

    Result: 

    END 

    Result: 

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022]  , or refer to  REMOVAL [07/2022 - ]