VEHICLE STABILITY CONTROL SYSTEM(for Vacuum Brake Booster), Diagnostic DTC:C1422

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

DESCRIPTION

Refer to DTCs C1421, C1423 and C1424 Click here.

DTC Code DTC Detection Condition Trouble Area
C1422 When the stop light switch is off, the PMC terminal voltage is higher than 0.86 V for 5 seconds or more while the vehicle is being driven at a speed of 3 km/h (2mph) or more.

  • STOP fuse

  • Stop light switch assembly

  • Stop light switch assembly circuit

  • Master cylinder pressure sensor circuit

  • Brake actuator assembly (Master cylinder pressure sensor)

WIRING DIAGRAM

Refer to DTC C1425 Click here.

CAUTION / NOTICE / HINT

Note


  • When replacing the skid control ECU (brake actuator assembly), perform calibration Click here.

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

Tech Tips

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

PROCEDURE


  1. READ VALUE USING GTS (STOP LIGHT SW)


    1. Turn the ignition switch off

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the GTS on.

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

      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

      		 -

    6. Check that the stop light switch display observed on the GTS changes according to the brake pedal operation.

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

    NG

    CHECK TERMINAL VOLTAGE AND RESISTANCE (STOP LIGHT SWITCH ASSEMBLY POWER SOURCE TERMINAL) Click here

    OK

  2. 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

  3. RECONFIRM DTC


    1. Clear the DTCs Click here.

    2. Start the engine.

    3. Drive the vehicle at a speed of 40 km/h (25 mph) or more and perform a braking test (decelerate the vehicle by depressing the brake pedal).

    4. Check if the same DTC is output Click here.

      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 Click here

  4. CHECK TERMINAL VOLTAGE AND RESISTANCE (STOP LIGHT SWITCH ASSEMBLY POWER SOURCE TERMINAL)


    1. Make sure that there is no looseness in the locking part and connecting part of the connectors.

    2. Disconnect the A99 stop light switch assembly connector.

    3. B001HUKE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Stop Light Switch Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A99-7(B) - Body ground Always 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A99-2 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK TERMINAL VOLTAGE (STP)


    1. Make sure that there is no looseness at the locking parts and connecting parts of the connectors.

    2. Disconnect the A6 skid control ECU (brake actuator assembly) connector.

    3. B001CDXE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A6-2 (STP) - Body ground Brake pedal depressed 8 to 14 V
      Brake pedal released Below 1.5 V

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    NG

  6. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY- BRAKE ACTUATOR ASSEMBLY)


    1. Disconnect the A99 stop light switch assembly connector.

    2. Disconnect the A6 skid control ECU (brake actuator assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A99-1 (OUT) - A6-2 (STP) Always Below 1 Ω
      A99-1 (OUT) or A6-2 (STP) - Body ground Always 10 kΩ or higher

    OK

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR