VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1281

DTC Code DTC Name
C1281 Master Cylinder Pressure Sensor Output Malfunction (Test Mode DTC)

DESCRIPTION

DTC C1281 will be deleted 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 Code DTC Detection Condition Trouble Area
C1281 Detected only during Test Mode.

  • Stop light switch

  • Brake pedal load sensing switch

  • Master cylinder pressure sensor

WIRING DIAGRAM

Refer to DTCs C1425 and C1429 Click here, or Click here.

INSPECTION PROCEDURE

Note

When replacing the brake actuator assembly, perform zero point calibration 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 ON INTELLIGENT TESTER (STOP LIGHT SWITCH AND BRAKE PEDAL LOAD SENSING SWITCH)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG).

    3. Select the Data List mode on the intelligent tester Click here.

      ABS / VSC / TRC:
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Stop Lamp SW Stop light switch / 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 the specified point

      OFF: Brake pedal not depressed beyond the specified point

      		 -

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

      OK
      The intelligent tester 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
      Result Proceed to
      OK A
      NG (Turning on of the stop light switch is not confirmed) 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

    B

    INSPECT SKID CONTROL ECU (STP TERMINAL) Click here

    C

    INSPECT SKID CONTROL ECU (FSW+ TERMINAL) Click here

    D

    CHECK BRAKE PEDAL AND STOP LIGHT SWITCH INSTALLATION Click here

    A

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


    1. Select the Data List mode on 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.: 5 V 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, voltage displayed on the intelligent tester increases.

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    OK

  4. PERFORM TEST MODE (SIGNAL CHECK)


    1. Turn the ignition switch off.

    2. Perform the sensor check in the Test Mode procedure Click here.

      OK
      All Test Mode DTCs are erased.

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    OK

    CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) Click here

  5. INSPECT SKID CONTROL ECU (STP TERMINAL)


    1. A017EHAE44

      Turn the ignition switch off.

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

    3. Disconnect the skid control ECU connector.

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      A24-2 (STP) - Body ground

      Stop light switch ON

      (Brake pedal depressed)

      		 8 to 14 V
      A24-2 (STP) - Body ground

      Stop light switch OFF

      (Brake pedal released)

      		 Below 1.5 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

  6. INSPECT SKID CONTROL ECU (FSW+ TERMINAL)


    1. A017EHAE45

      Turn the ignition switch off.

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

    3. Disconnect the skid control ECU connector.

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

      Standard resistance
      Tester Connection Switch Condition Specified Condition
      A24-27 (FSW+) - Body ground

      Brake pedal load sensing switch OFF

      (Brake pedal depressed)

      		 0.9 to 1.1 kΩ
      A24-27 (FSW+) - Body ground

      Brake pedal load sensing switch ON

      (Brake pedal released)

      		 192 to 234 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FSW+ CIRCUIT)

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

  7. CHECK BRAKE PEDAL AND STOP LIGHT SWITCH INSTALLATION


    1. Turn the ignition switch off.

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

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

    NG

    ADJUST BRAKE PEDAL OR STOP LIGHT SWITCH Click here

    OK

    REPLACE BRAKE PEDAL SUB-ASSEMBLY (BRAKE PEDAL LOAD SENSING SWITCH) Click here