VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1422

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

DESCRIPTION

DTC No. DTC Detection Condition Trouble Area
C1422

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 NO. 1 fuse

  • Stop light switch assembly

  • Wire harness or connector

  • Skid control ECU (Brake actuator assembly)

  • Brake actuator assembly (Master cylinder pressure sensor)

WIRING DIAGRAM

Refer to DTC C1425 Click here.

INSPECTION PROCEDURE

Note


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

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. CHECK DTC


    1. Clear the DTCs Click here.

    2. Turn the ignition switch off.

    3. Start the engine.

    4. Perform a road test.

    5. Check the DTCs Click here.

      Result
      Result Proceed to
      DTC C1422 is output A
      DTCs C1422 and C1425 are output B

    B

    GO TO DTC CHART Click here

    A

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


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

    5. In accordance with the display on the GTS, read the Data List.

      ABS/VSC/TRC
      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

      		 -

    6. 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.

    NG

    CHECK BRAKE PEDAL AND STOP LIGHT SWITCH ASSEMBLY INSTALLATION Click here

    OK

  3. READ VALUE USING GTS (MASTER CYLINDER PRESSURE SENSOR)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

    5. In accordance with the display on the GTS, read the Data List.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Master Cylinder Pressure Master cylinder pressure sensor pressure / Min.: 0.00 MPa, Max.: 23.28 MPa

      Brake pedal operated: Proportional to pedal force

      Brake pedal released: 0.00 to 1.76 MPa

      		 -
      OK
      Data List pressure is within standard range.

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    OK

  4. RECONFIRM DTC


    1. Clear the DTCs Click here.

    2. Turn the ignition switch off.

    3. Start the engine.

    4. Perform a road test.

    5. Check if the same DTC is recorded Click here.

      Result
      Result Proceed to
      DTC C1422 is not output A
      DTC C1422 is output B

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    A

    USE SIMULATION METHOD TO CHECK Click here

  5. CHECK BRAKE PEDAL AND STOP LIGHT SWITCH ASSEMBLY INSTALLATION


    1. Turn the ignition switch off.

    2. Check the brake pedal height and stop light switch assembly installation Click here.

      OK
      The brake pedal height and stop light switch assembly installation are normal.

    NG

    ADJUST BRAKE PEDAL OR STOP LIGHT SWITCH ASSEMBLY Click here

    OK

  6. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Remove the stop light switch assembly Click here.

    2. Inspect the stop light switch assembly Click here.

      OK
      The stop light switch assembly is normal.

    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    OK

  7. CHECK TERMINAL VOLTAGE (STP TERMINAL)


    1. B007V7YE04
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Turn the ignition switch off.

    2. Reinstall the stop light switch assembly Click here.

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

    4. Disconnect the B92 skid control ECU (brake actuator assembly) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      B92-35 (STP) - Body ground Stop light switch assembly on (Brake pedal depressed) 8 to 14 V
      B92-35 (STP) - Body ground Stop light switch assembly off (Brake pedal released) Below 1.5 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here