VEHICLE STABILITY CONTROL SYSTEM (for Hydraulic Brake Booster), Diagnostic DTC:C1422, C1456

DTC Code DTC Name
C1422 Master Cylinder Pressure Sensor Zero Point High Malfunction
C1456 Control Pressure Sensor Zero Point High

DESCRIPTION

Refer to DTCs C1421, C1423, C1424, C1455, C1457 and C1458 Click here.

DTC Code DTC Detection Condition Trouble Area
C1422 When the stop light switch is off, the PM/C1 terminal voltage is 0.86 V or higher for 5 seconds or more.

  • STOP fuse

  • Stop light switch assembly

  • Stop light switch circuit

  • Master cylinder pressure sensor circuit

  • Master cylinder solenoid (Master cylinder pressure sensor)
C1456 When the stop light switch is off, the PCTRL terminal voltage is 0.86 V or higher for 5 seconds or more.

  • STOP fuse

  • Stop light switch assembly

  • Stop light switch circuit

  • Pressure control sensor circuit

  • Master cylinder solenoid (Pressure control sensor)

WIRING DIAGRAM

Refer to DTC C1425 Click here.

INSPECTION PROCEDURE

Note


  • When replacing the skid control ECU (master cylinder solenoid), 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 and/or C1456, inspect and repair the trouble areas indicated by DTC C1425 first Click here.

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (STOP LIGHT SW)


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the intelligent tester 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 intelligent tester changes according to brake pedal operation.

      OK
      The intelligent tester 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 DTC Click here.

    2. Start the engine.

    3. Drive the vehicle at a speed of 40 km/h (25 mph) or more and perform 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 is not output A
      DTC is output (for LHD) B
      DTC is output (for RHD) C

    B

    REPLACE MASTER CYLINDER SOLENOID Click here

    C

    REPLACE MASTER CYLINDER SOLENOID Click here

    A

    USE SIMULATION METHOD TO CHECK 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 A85 stop light switch assembly connector.

    3. A01DUWFE09
      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
      A85-1(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
      A85-3 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK TERMINAL VOLTAGE (STP)


    1. Disconnect the A7 skid control ECU (master cylinder solenoid) connector.

    2. A01DRS6E31
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU [Master Cylinder Solenoid])

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A7-7 (STP) - Body ground Brake pedal depressed 8 to 14 V
      Brake pedal released Below 1.5 V
      Result
      Result Proceed to
      NG A
      OK (for LHD) B
      OK (for RHD) C

    B

    REPLACE MASTER CYLINDER SOLENOID Click here

    C

    REPLACE MASTER CYLINDER SOLENOID Click here

    A

  6. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - MASTER CYLINDER SOLENOID)


    1. Disconnect the A85 stop light switch assembly connector.

    2. Disconnect the A7 skid control ECU (master cylinder solenoid) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A85-2 (L) - A7-7 (STP) Always Below 1 Ω
      A85-2 (L) or A7-7 (STP) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here