ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1422

DTC Code DTC Name
C1422 Master Cylinder Pressure Sensor Zero Point High Malfunction

DESCRIPTION

DTC No. Detection Item DTC Detection Condition Trouble Area Note
C1422 Master Cylinder Pressure Sensor Zero Point High Malfunction When vehicle speed is 3 km/h (2 mph) or more and stop light switch assembly is OFF, master cylinder pressure continuously exceeds 1.764 MPa (18.0 kgf/cm2, 255 psi) for 5 seconds or more.

  • Stop light switch assembly

  • Wire harness or connector

  • Skid control ECU (Brake actuator assembly)

  • Master cylinder pressure sensor (Brake actuator assembly)

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WIRING DIAGRAM

Refer to DTC C1380.

Click here

CAUTION / NOTICE / HINT

Note

When replacing the skid control ECU (brake actuator assembly), perform zero point calibration and store system information.

Click here

PROCEDURE


  1. CHECK DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the engine switch off.

    3. Start the engine.

    4. Perform a road test.

    5. Check for DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Proceed to
      DTC C1422 is output
      DTCs C1422 and C1380 are output
      DTCs C1422 and C1425 are output

    DTCs C1422 and C1380 are output

    GO TO DTC CHART Click here

    DTCs C1422 and C1425 are output

    GO TO DTC CHART Click here

    DTC C1422 is output

  2. READ VALUE USING GTS (STOP LIGHT SWITCH ASSEMBLY)


    1. Connect the GTS to the DLC3.

    2. Start the engine.

    3. Select the Data List using the GTS.

      Click here


      Chassis > ABS/VSC/TRC > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light SW Stop light switch assembly ON or OFF

      ON: Brake pedal depressed

      OFF: Brake pedal released

      		 -

      Chassis > ABS/VSC/TRC > Data List
      Tester Display
      Stop Light SW

    4. Check that the stop light switch assembly condition observed on the GTS changes according to brake pedal operation.

      OK
      The GTS displays ON or OFF according to brake pedal operation.
      Result
      Proceed to
      OK
      NG

    NG

    CHECK STOP LIGHT SWITCH ASSEMBLY INSTALLATION Click here

    OK

  3. READ VALUE USING GTS (MASTER CYLINDER SENSOR)


    1. Select the Data List using the GTS.

      Click here


      Chassis > ABS/VSC/TRC > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Master Cylinder Pressure Master cylinder pressure sensor pressure

      Min.: 0.00 MPa

      Max.: 24.48 MPa

      Brake pedal operated: Proportional to pedal force

      Brake pedal released: 0.00 to 1.76 MPa

      		 -

      Chassis > ABS/VSC/TRC > Data List
      Tester Display
      Master Cylinder Pressure
      OK
      Data List pressure is within standard range.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY for LHD: Click here
    REPLACE BRAKE ACTUATOR ASSEMBLY for RHD: Click here

    OK

  4. RECONFIRM DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the engine switch off.

    3. Start the engine.

    4. Drive the vehicle and perform a braking test (decelerate the vehicle by depressing the brake pedal).

    5. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C1422 is not output. A
      DTC C1422 is output. B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY for LHD: Click here
    REPLACE BRAKE ACTUATOR ASSEMBLY for RHD: Click here

  5. CHECK STOP LIGHT SWITCH ASSEMBLY INSTALLATION


    1. Turn the engine switch off.

    2. Check the stop light switch assembly installation.

      for LHD: Click here

      for RHD: Click here

      OK
      The brake pedal height and stop light switch assembly installation are normal.
      Result
      Proceed to
      OK
      NG

    NG

    ADJUST STOP LIGHT SWITCH ASSEMBLY INSTALLATION for LHD: Click here
    ADJUST STOP LIGHT SWITCH ASSEMBLY INSTALLATION for RHD: Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. Turn the engine switch off.

    2. Make sure that there is no looseness at the locking part and the connecting part of the connector.

    3. Disconnect the A9 skid control ECU (brake actuator assembly) connector.

    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      A9-35 (STP) - Body ground Stop light switch assembly on (Brake pedal depressed) 8 to 14 V
      A9-35 (STP) - Body ground Stop light switch assembly off (Brake pedal released) Below 1.5 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY for LHD: Click here
    REPLACE BRAKE ACTUATOR ASSEMBLY for RHD: Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)