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VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1281, C1422

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DTC Code DTC Name
C1281 Master Cylinder Pressure Sensor Output Malfunction (Test Mode DTC)
C1422 Master Cylinder Pressure Sensor Zero Point High Malfunction
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DESCRIPTION

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

DTC C1281 will be cleared when the master cylinder pressure sensor sends a master cylinder pressure signal or when Test Mode ends. DTC C1281 is output only in Test Mode.

DTC No. Detection Item DTC Detection Condition Trouble Area
C1281 Master Cylinder Pressure Sensor Output Malfunction (Test Mode DTC) Detected only during Test Mode.

  • Stop light switch assembly

  • Master cylinder pressure sensor (brake actuator assembly)

  • Brake pedal load sensing switch (brake pedal support assembly)
C1422 Master Cylinder Pressure Sensor Zero Point High Malfunction 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 circuit

  • Master cylinder pressure sensor circuit

  • Master cylinder pressure sensor (brake actuator assembly)
Tip:

for C1422: Even after the trouble areas are repaired, the ABS warning light will not go off unless the following operations are performed:


  1. Turn the engine switch on (IG).

  2. Keep the vehicle stationary for 5 seconds or more and depress the brake pedal lightly 2 or 3 times.

  3. Drive the vehicle at the vehicle speed of 50 km/h (31 mph) and depress and hold the brake pedal firmly for approximately 3 seconds.

  4. Repeat the above operation 3 times or more and check that the ABS warning light goes off.

  5. Clear the DTCs.

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WIRING DIAGRAM

Refer to DTC C1425 and C1429.

for C1425:Click here

for C1429:Click here

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CAUTION / NOTICE / HINT

Note:

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

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

Tip:

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

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PROCEDURE


  1. Click here

    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
      Result
      Proceed to
      OK
      NG

  2. Click here

    READ VALUE USING GTS (STOP LIGHT SWITCH ASSEMBLY AND BRAKE PEDAL LOAD SENSING SWITCH)


    1. Connect the GTS to the DLC3.

    2. Start the engine.

    3. Select the Data List using the GTS.

      Click here


      1. 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

        		 -
        Brake Pedal Load Sensing SW Brake pedal load sensing switch ON or OFF

        ON: Brake pedal depressed beyond a specified point

        OFF: Brake pedal not depressed beyond a specified point

        		 -




      1. Chassis > ABS/VSC/TRC > Data List
        Tester Display
        Stop Light SW
        Brake Pedal Load Sensing SW





    4. Check that the stop light switch display and brake pedal load sensing switch display observed on the GTS change according to brake pedal operation.

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

    5. Slowly depress the brake pedal, and check when the stop light switch and brake pedal load sensing switch turn on.

      OK
      First the stop light switch should turn on, and then the brake pedal load sensing switch should turn on.
      Result
        Proceed to
      OK A
      NG (The stop light switch does not turn on.) B
      NG (Turning on of the brake pedal load sensing switch is not confirmed.) C
      NG (The brake pedal load sensing switch turns on first.) D

  3. Click here

    READ VALUE USING GTS (MASTER CYLINDER PRESSURE SENSOR)


    1. Select the Data List using the GTS.

      Click here


      1. Chassis > ABS/VSC/TRC > Data List
        Tester Display Measurement Item Range Normal Condition Diagnostic Note
        Master Cylinder Sensor Master cylinder pressure sensor reading Min.: 0.00 V, Max.: 5.00 V Brake pedal released: 0.30 to 0.80 V Reading increases when brake pedal is depressed



      1. Chassis > ABS/VSC/TRC > Data List
        Tester Display
        Master Cylinder Sensor




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

      OK
      When the pedal is depressed, the voltage displayed on the GTS increases.
      Result
      Proceed to
      OK
      NG

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    RECONFIRM DTC


    1. Clear the DTCs.

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      1. 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.

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      1. Chassis > ABS/VSC/TRC > Trouble Codes


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

  5. Click here

    CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. B0066KWC41
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      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 A15 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
      A15-2 (STP) - Body ground Stop light switch assembly on (Brake pedal depressed) 8 to 14 V
      A15-2 (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)

  6. Click here

    INSPECT BRAKE PEDAL SUPPORT ASSEMBLY


    1. B0065SNC01
      *a

      Component without harness connected

      (Brake Pedal Load Sensing Switch (Brake Pedal Support Assembly))

      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 A51 brake pedal load sensing switch (brake pedal support assembly) connector.

      Note:

      • Do not remove the brake pedal load sensing switch from the brake pedal support assembly.

      • When there is a malfunction in the brake pedal load sensing switch, replace the brake pedal support assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 (FSW+) - 1 (FSW-) Brake pedal load sensing switch off (Brake pedal depressed) 950 to 1050 Ω
      2 (FSW+) - 1 (FSW-) Brake pedal load sensing switch on (Brake pedal released) 203 to 223 Ω
      Result
      Proceed to
      OK
      NG

  7. Click here

    CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - BRAKE PEDAL SUPPORT ASSEMBLY)


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

    2. Disconnect the A15 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
      A15-27 (FSW+) - A51-2 (FSW+) Always Below 1 Ω
      A15-27 (FSW+) or A51-2 (FSW+) - Body ground Always 10 kΩ or higher
      A51-1 (FSW-) - Body ground Always Below 1 Ω
      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

  8. Click here

    CHECK BRAKE PEDAL HEIGHT AND STOP LIGHT SWITCH ASSEMBLY INSTALLATION


    1. Turn the engine switch off.

    2. Check the brake pedal height and 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

    • OK

      REPLACE BRAKE PEDAL SUPPORT ASSEMBLY for LHD:Click here

      REPLACE BRAKE PEDAL SUPPORT ASSEMBLY for RHD:Click here

    • NG

      ADJUST BRAKE PEDAL HEIGHT OR STOP LIGHT SWITCH ASSEMBLY INSTALLATION for LHD:Click here

      ADJUST BRAKE PEDAL HEIGHT OR STOP LIGHT SWITCH ASSEMBLY INSTALLATION for RHD:Click here