VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1422

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

DESCRIPTION

The master cylinder pressure sensor is connected to the skid control ECU in the brake actuator assembly.

A015Z9ZE17
DTC Code DTC Detection Condition Trouble Area
C1422 When driving at 3 km/h (2 mph) or more with the stop light switch off, the PMC terminal voltage exceeds 0.86 V for 5 seconds or more.

  • Stop light switch

  • Stop light switch circuit

  • Master cylinder pressure sensor circuit

  • Brake actuator assembly (Master cylinder pressure sensor)

WIRING DIAGRAM

Refer to DTC C1425 Click here.

INSPECTION PROCEDURE

Note


  • When replacing the 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 procedure.

Tech Tips

When DTC C1425 and/or C1426 is output together with DTC C1422, inspect and repair the trouble areas indicated by DTC C1425 and/or C1426 first Click here, or Click here.

PROCEDURE


  1. CHECK STOP LIGHT OPERATION


    1. Check that the stop lights come on when the brake pedal is depressed, and go off when the brake pedal is released.

      OK
      Condition Illumination Condition
      Brake pedal depressed On
      Brake pedal released Off

    NG

    INSPECT STOP LIGHT CIRCUIT Click here

    OK

  2. READ VALUE USING INTELLIGENT TESTER (STOP LIGHT SWITCH)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Select the Data List using the intelligent tester Click here.

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

      ON: Brake pedal depressed

      OFF: Brake pedal released

      		 -

    4. Check that the stop light switch display observed on the intelligent tester changes according to brake pedal operation.

      OK
      The intelligent tester displays ON or OFF according to brake pedal operation.

    NG

    CHECK STOP LIGHT SWITCH INSTALLATION Click here

    OK

  3. READ VALUE USING INTELLIGENT TESTER (MASTER CYLINDER PRESSURE SENSOR)


    1. Select the Data List using the intelligent tester Click here.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Master Cylinder Sensor Master cylinder pressure sensor / min.: 0 V, max.: 5V When brake pedal is released: 0.3 to 0.9 V Reading increases when brake pedal is depressed

    2. Check that the brake fluid pressure value of the master cylinder pressure sensor observed on the intelligent tester changes when the brake pedal is depressed.

      OK
      When the pedal is depressed, the voltage displayed on the intelligent tester increases.

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    OK

  4. RECONFIRM DTC


    1. Clear the DTCs Click here.

    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 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

    CHECK FOR INTERMITTENT PROBLEMS Click here

  5. CHECK STOP LIGHT SWITCH INSTALLATION


    1. Turn the engine switch off.

    2. Check that the stop light switch has been installed properly Click here.

      OK
      The stop light switch installation is normal.

    NG

    INSTALL STOP LIGHT SWITCH CORRECTLY Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (STP1 TERMINAL)


    1. A01613JE48
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)

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

    2. Disconnect the skid control ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A62-2 (STP1) - Body ground

      Stop light switch ON

      (Brake pedal depressed)

      		 8 to 14 V
      A62-2 (STP1) - Body ground

      Stop light switch OFF

      (Brake pedal released)

      		 Below 1.5 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP1 CIRCUIT)

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here