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Home >> Lexus >> 2020 >> LC 500 >> Repair and Diagnosis >> Brakes >> Mechanical - Hydraulic >> Electronically Controlled Brake System - Diagnostic Codes (Coupe) (2 Of 4) >> Electronically Controlled Brake System >> DTC C1247/47: Stroke Sensor Malfunction; DTC C1392/48: Stroke Sensor Zero Point Calibration Undone [03/2017 - 09/2018] >> Procedure

DTC C1247/47: Stroke Sensor Malfunction; DTC C1392/48: Stroke Sensor Zero Point Calibration Undone [03/2017 - 09/2018]: Procedure

  1. CHECK BRAKE PEDAL 
    1. Check that the brake pedal and the brake pedal stroke sensor assembly are properly installed and that the pedal can be depressed normally.
    2. Check and adjust the brake pedal height.

      Refer to PROCEDURE - Step 2

    3. Adjust the brake pedal stroke sensor assembly.

      Refer to INSTALLATION [03/2017 - 05/2023]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  2

  2. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU ASSEMBLY - BRAKE PEDAL STROKE SENSOR ASSEMBLY) 
    1. Make sure that there is no looseness at the locking part and the connecting part of the connectors.
    2. Disconnect the A10 skid control ECU assembly connector.
    3. Disconnect the A3 brake pedal stroke sensor assembly connector.
    4. Check both the connector case and the terminal for deformation and corrosion.

      OK

      No deformation or corrosion.

    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A10-8 (SKG) - A3-1 (SKG) Always Below 1 Ω
      A10-8 (SKG) or A3-1 (SKG) - Body ground Always 10 kΩ or higher
      A10-10 (VCSK) - A3-3 (VCSK) Always Below 1 Ω
      A10-10 (VCSK) or A3-3 (VCSK) - Body ground Always 10 kΩ or higher
      A10-20 (SKS) - A3-2 (SKS1) Always Below 1 Ω
      A10-20 (SKS) or A3-2 (SKS1) - Body ground Always 10 kΩ or higher
      A10-22 (SKS2) - A3-4 (SKS2) Always Below 1 Ω
      A10-22 (SKS2) or A3-4 (SKS2) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  3

  3. PERFORM INITIALIZATION AND CALIBRATION OF LINEAR SOLENOID VALVE 
    1. Reconnect the A10 skid control ECU assembly connector.
    2. Reconnect the A3 brake pedal stroke sensor assembly connector.
    3. Perform initialization and calibration of the linear solenoid valve.

      Refer to INITIALIZATION [03/2017 - ]

      Chassis > ABS/VSC/TRAC > Utility 

      Tester Display
      ECB Utility

      ECB: Electronically Controlled Brake System

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  4

  4. RECONFIRM DTC 
    1. Turn the engine switch off.
    2. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [03/2017 - 09/2018]

      Chassis > ABS/VSC/TRAC > Clear DTCs 

    3. Turn the engine switch off.
    4. Start the engine.
    5. Perform a road test.
    6. Check if the same DTC is output.

      Refer to DTC CHECK / CLEAR [03/2017 - 09/2018]

      Chassis > ABS/VSC/TRAC > Trouble Codes 

      Result

      Result Proceed to
      DTCs C1247/47 and/or C1392/48 are output. A
      DTCs C1247/47 and C1392/48 are not output. B

    Result: 

    B 

    END 

    Result: 

    A 

    See step  5

  5. INSPECT SKID CONTROL ECU ASSEMBLY (SENSOR POWER SUPPLY OUTPUT) 
    1. Turn the engine switch on (IG).
      GTY788351Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Skid Control ECU Assembly)
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A10-10 (VCSK) - Body ground Engine switch on (IG) 4.5 to 5.5 V
    3. Turn the engine switch off.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A10-8 (SKG) - Body ground Engine switch off Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE SKID CONTROL ECU ASSEMBLY. Refer to  REMOVAL [03/2017 - 05/2023] 

    Result: 

    OK 

    See step  6

  6. READ VALUE USING TECHSTREAM (BRAKE PEDAL STROKE SENSOR ASSEMBLY) 
    1. Mount a pedal effort gauge.
    2. Connect the Techstream to the DLC3.
    3. Turn the engine switch on (IG).
    4. Select the Data List on the Techstream.

      Refer to DATA LIST / ACTIVE TEST [03/2017 - 05/2023]

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stroke Sensor Brake pedal stroke sensor assembly 1 Min.: 0.00 V, Max.: 5.00 V Brake pedal released: 0.80 to 1.20 V Reading increases when brake pedal is depressed
      Stroke Sensor2 Brake pedal stroke sensor assembly 2 Min.: 0.00 V, Max.: 5.00 V Brake pedal released: 3.80 to 4.20 V Reading decreases when brake pedal is depressed

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display
      Stroke Sensor
      Stroke Sensor2
    5. When depressing the brake pedal with the amount of force listed in the table below, check that the output value displayed on the Techstream is within the standard voltage.

      HINT: 

      The brake pedal must be depressed gradually.

      Standard Voltage

      Brake Effort
      N (kgf, lbf)      		 Stroke Sensor
      (Tester Display)      		 Stroke Sensor2
      (Tester Display)
      50 (5, 11.2) 1.37 to 1.77 V 3.18 to 3.58 V
      100 (10, 22.5) 1.62 to 2.02 V 3.00 to 3.40 V
      150 (15, 33.7) 1.77 to 2.17 V 2.79 to 3.19 V
      200 (20, 45.0) 1.87 to 2.27 V 2.68 to 3.08 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE BRAKE PEDAL STROKE SENSOR ASSEMBLY. Refer to  REMOVAL [03/2017 - 05/2023] 

    Result: 

    OK 

    See step  7

  7. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU ASSEMBLY - BRAKE ACTUATOR ASSEMBLY) 
    1. Turn the engine switch off.
    2. Make sure that there is no looseness at the locking part and the connecting part of the connectors.
    3. Disconnect the A11 and A8 skid control ECU assembly connectors.
    4. Disconnect the A7 brake actuator assembly connector.
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A8-9 (VCM) - A7-10 (VCM) Always Below 1 Ω
      A8-9 (VCM) or A7-10 (VCM) - Body ground Always 10 kΩ or higher
      A8-21 (PAC1) - A7-15 (PAC1) Always Below 1 Ω
      A8-21 (PAC1) or A7-15 (PAC1) - Body ground Always 10 kΩ or higher
      A8-30 (PMC1) - A7-13 (PMC1) Always Below 1 Ω
      A8-30 (PMC1) or A7-13 (PMC1) - Body ground Always 10 kΩ or higher
      A8-8 (E) - A7-14 (E) Always Below 1 Ω
      A8-8 (E) or A7-14 (E) - Body ground Always 10 kΩ or higher
      A8-31 (PCK1) - A7-12 (PCK1) Always Below 1 Ω
      A8-31 (PCK1) or A7-12 (PCK1) - Body ground Always 10 kΩ or higher
      A11-16 (VCM2) - A7-5 (VCM2) Always Below 1 Ω
      A11-16 (VCM2) or A7-5 (VCM2) - Body ground Always 10 kΩ or higher
      A11-28 (PMC2) - A7-8 (PMC2) Always Below 1 Ω
      A11-28 (PMC2) or A7-8 (PMC2) - Body ground Always 10 kΩ or higher
      A11-15 (E2) - A7-16 (E2) Always Below 1 Ω
      A11-15 (E2) or A7-16 (E2) - Body ground Always 10 kΩ or higher
      A11-29 (PCK2) - A7-7 (PCK2) Always Below 1 Ω
      A11-29 (PCK2) or A7-7 (PCK2) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  8

  8. INSPECT SKID CONTROL ECU ASSEMBLY (SENSOR POWER SUPPLY OUTPUT) 
    1. Reconnect the A11 and A8 skid control ECU assembly connectors.
      GTY788356Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Skid Control ECU Assembly)
    2. Reconnect the A7 brake actuator assembly connector.
    3. Turn the engine switch on (IG).
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A8-9 (VCM) - Body ground Engine switch on (IG) 4.75 to 5.25 V
      A11-16 (VCM2) - Body ground Engine switch on (IG) 4.75 to 5.25 V
    5. Turn the engine switch off.
    6. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A8-8 (E) - Body ground Engine switch off Below 1 Ω
      A11-15 (E2) - Body ground Engine switch off Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE SKID CONTROL ECU ASSEMBLY. Refer to  REMOVAL [03/2017 - 05/2023] 

    Result: 

    OK 

    See step  9

  9. READ VALUE USING TECHSTREAM (MASTER CYLINDER PRESSURE SENSOR) 
    1. Mount a pedal effort gauge.
    2. Connect the Techstream to the DLC3.
    3. Turn the engine switch on (IG).
    4. Select the Data List on the Techstream.

      Refer to DATA LIST / ACTIVE TEST [03/2017 - 05/2023]

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Master Cylinder Sensor Master cylinder pressure sensor 1 Min.: 0.00 V, Max.: 5.00 V Brake pedal released: 0.30 to 0.70 V Reading increases when brake pedal is depressed
      Master Cylinder Sensor2 Master cylinder pressure sensor 2 Min.: 0.00 V, Max.: 5.00 V Brake pedal released: 0.30 to 0.70 V Reading increases when brake pedal is depressed
      ECB Solenoid (SMC1) Master cut solenoid (SMC1) ON or OFF ON: Solenoid on (valve closed)
      OFF: Solenoid off (valve open)      		 ECB: Electronically Controlled Brake System
      ECB Solenoid (SMC2) Master cut solenoid (SMC2) ON or OFF ON: Solenoid on (valve closed)
      OFF: Solenoid off (valve open)      		 ECB: Electronically Controlled Brake System

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display
      Master Cylinder Sensor
      Master Cylinder Sensor2
      ECB Solenoid (SMC1)
      ECB Solenoid (SMC2)

      ECB: Electronically Controlled Brake System

    5. Check the output value of the master cylinder pressure sensor as the brake pedal is depressed.

      OK

      Output voltage is proportional to pedal stroke, and there is not a large difference in output between sensor 1 and sensor 2.

      HINT: 

      • If DTCs are stored due to the brake pedal being depressed, and electronically controlled brake system control is prohibited, check the Freeze Frame Data recorded at the time the DTCs were stored.
      • If the Freeze Frame Data shows that there are no abnormalities in the output of the master cylinder pressure sensors and difference in the output between sensor 1 and sensor 2, proceed to the next step.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE SKID CONTROL ECU ASSEMBLY. Refer to  REMOVAL [03/2017 - 05/2023] 

    Result: 

    NG 

    REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [03/2017 - 05/2023] 

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