ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C14B6

DTC Code DTC Name
C14B6 Stroke Sensor / Reaction Force Pressure Sensor Output Inconsistent

DESCRIPTION

If the skid control ECU (brake booster with master cylinder assembly) detects an inconsistency between the brake pedal stroke sensor assembly signal and reaction force pressure sensor signal, DTC C14B6 is stored.

DTC No. Detection Item INF Code DTC Detection Condition Trouble Area Note
C14B6 Stroke Sensor / Reaction Force Pressure Sensor Output Inconsistent 209 The difference between brake pedal stroke sensor assembly output value and reaction force pressure sensor output value is above the threshold for a certain period of time.

  • Brake actuator (brake booster with master cylinder assembly)

  • Brake pedal stroke sensor assembly

 Electronically controlled brake system DTC

CAUTION / NOTICE / HINT

Note

After replacing the brake actuator (brake booster with master cylinder assembly) or brake pedal stroke sensor assembly perform linear solenoid valve offset learning, ABS holding solenoid valve learning, yaw rate and acceleration sensor zero point calibration and system information memorization after performing "Reset Memory".

Click here

PROCEDURE


  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 GTS, read the "Shift Lever Position", "Vehicle Speed", "Yaw Rate Sensor", "Steering Angle 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.

      Tech Tips


      • 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

    NEXT

  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.

      Tech Tips

      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 GTS.

      Click here


      Chassis > ABS/VSC/TRC > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stroke Sensor Brake pedal stroke sensor assembly 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/TRC > 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) 1.14 to 1.84 0.03 (0.3, 4.4) to 2.03 (20.7, 294)
      500 (51, 112.4) 1.31 to 2.01 2.00 (20.4, 290) to 4.00 (40.8, 580)
      for Front Left Wheel

      Brake Effort

      [N (kgf, lbf)]

      Stroke Sensor

      [V]

      Hydraulic Pressure

      [MPa (kgf/cm2, psi)]
      200 (20, 45.0) 1.14 to 1.84 0.03 (0.3, 4.4) to 2.03 (20.7, 294)
      500 (51, 112.4) 1.31 to 2.01 2.00 (20.4, 290) to 4.00 (40.8, 580)
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY for LHD: Click here
    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY for RHD: Click here

    NG

  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.

      for LHD: Click here

      for RHD: Click here

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

      Click here


      Chassis > ABS/VSC/TRC > Utility
      Tester Display
      ECB Utility
      Result
      Proceed to
      NEXT

    NEXT

  4. RECONFIRM DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > 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.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C14B6 is not output. A
      DTC C14B6 is output. B

    A

    END

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY for LHD: Click here
    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY for RHD: Click here