VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1246/46, C1281/81

DTC Code DTC Name
C1246/46 Master Cylinder Pressure Sensor Malfunction
C1281/81 Master Cylinder Pressure Sensor Output Malfunction (Test Mode DTC)

DESCRIPTION

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

DTC C1281/81 is output only in the Test Mode (signal check).

A01CFFME09
DTC No. DTC Detection Condition Trouble Area
C1246/46

When any of the following is detected:


  1. The voltage of the sensor signal is out of range (less than 0.3 V, more than 4.86 V).

  2. The sensor supply voltage is out of range (above 5.3 V, below 4.7 V).

  3. The sensor signal offset value is out of range.

  4. The sum of signal 1 and signal 2 is out of range (above 5.5 V, below 4.5 V).

  • Stop light switch circuit

  • Master cylinder pressure sensor circuit

  • Brake actuator assembly (Master cylinder pressure sensor)

WIRING DIAGRAM

Refer to DTC C1249/49 Click here.

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK STOP LIGHT OPERATION


    1. Check that the stop light comes on when the brake pedal is depressed, and goes 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 (MASTER CYLINDER PRESSURE SENSOR)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine.

    3. 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 reading / min.: 0 V, max.: 5 V When brake pedal is released: 0.3 to 0.9 V Reading increases when brake pedal is depressed

    4. 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

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


    1. 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

      		 -

    2. Check that the stop light condition observed on the intelligent tester changes when the brake pedal is depressed.

      OK
      When the brake pedal is depressed, the intelligent tester displays "ON".

    NG

    INSPECT SKID CONTROL ECU (STP1 TERMINAL) Click here

    OK

  4. RECONFIRM DTC


    1. Turn the engine switch off.

    2. Clear the DTC Click here.

    3. Start the engine.

    4. At a speed of 30 km/h (18 mph) or more, drive the vehicle and perform 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 (C1246/46) is not output A
      DTC (C1246/46) is output B

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) Click here

  5. INSPECT SKID CONTROL ECU (STP1 TERMINAL)


    1. A01CFJZE50

      Turn the engine switch off.

    2. Disconnect the skid control ECU connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A10-30 (STP) - Body ground Stop light switch ON (Brake pedal depressed) 8 to 14 V
      A10-30 (STP) - 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