ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1246/46, C1281/81, C1364/61

DTC Code DTC Name
C1246/46 Master Cylinder Pressure Sensor Malfunction
C1281/81 Master Cylinder Pressure Sensor Output Malfunction (Test Mode DTC)
C1364/61 Wheel Cylinder Pressure Sensor Malfunction

DESCRIPTION

The master cylinder pressure sensor and the wheel cylinder pressure sensor are built into the brake actuator. They measure the master cylinder pressure and the wheel cylinder pressure and send the data to the skid control ECU.

DTC C1281/81 can be deleted when the master cylinder pressure sensor sends a master cylinder pressure signal or the Test Mode ends. DTC C1281/81 is output only in the Test Mode.

DTC Code Information Code DTC Detection Condition Trouble Area
C1246/46 191 Sensor power source 1 (VCM) voltage is less than 4.7 V or 5.3 V or more for at least 0.05 seconds.

  • Master cylinder pressure sensor

  • Master cylinder pressure sensor circuit

  • Master cylinder pressure sensor power supply

  • Brake actuator

  • Skid control ECU
↑ 192 Master cylinder pressure sensor output voltage 1 (PMC1) is less than 0.25 V or 4.53 V or more for at least 0.05 seconds.

  • Master cylinder pressure sensor

  • Master cylinder pressure sensor circuit

  • Brake actuator

  • Skid control ECU
↑ 194 Sensor power source 2 (VCM2) voltage is less than 4.7 V or 5.3 V or more for at least 0.05 seconds.

  • Master cylinder pressure sensor

  • Master cylinder pressure sensor circuit

  • Master cylinder pressure sensor power supply

  • Brake actuator

  • Skid control ECU
↑ 195 Master cylinder pressure sensor output voltage 2 (PMC2) is less than 0.25 V or 4.53 V or more for at least 0.05 seconds.

  • Master cylinder pressure sensor

  • Master cylinder pressure sensor circuit

  • Brake actuator

  • Skid control ECU
↑ 197 Master cylinder pressure sensor output voltage 1 (PMC1) is abnormal. ↑
↑ 198 Master cylinder pressure sensor output voltage 2 (PMC2) is abnormal. ↑
↑ 199 Master cylinder pressure sensor output voltage 1 (PMC1) is less than 0.33 V or 0.85 V or more when not braking.

  • Master cylinder pressure sensor

  • Master cylinder pressure sensor circuit

  • Brake actuator

  • Skid control ECU
↑ 200 Master cylinder pressure sensor output voltage 2 (PMC2) is less than 0.33 V or 0.85 V or more when not braking. ↑
↑ 201 PMC1 and PMC2 voltages are different. ↑
↑ 202 Condition that output voltage of front pressure sensor LH (PFL) and rear pressure sensor RH (PRR) is 0.25 V or less or 4.53 V or more continues for 0.05 sec. or more

  • Master cylinder pressure sensor power supply

  • Brake actuator

  • Skid control ECU
↑ 205 Condition that output voltage of front pressure sensor RH (PFR) and rear pressure sensor LH (PRL) is 0.25 V or less or 4.53 V or more continues for 0.05 sec. or more ↑
C1364/61 221 Sensor power source 1 (VCM1) voltage is less than 4.7 V or 5.3 V or more for at least 0.05 seconds.

  • Wheel cylinder pressure sensor power supply

  • Brake actuator

  • Skid control ECU
↑ 222 Front wheel cylinder pressure sensor RH output voltage (PFR) is less than 0.25 V or 4.53 V or more for at least 0.05 seconds.

  • Wheel cylinder pressure sensor

  • Wheel cylinder pressure sensor circuit

  • Brake actuator

  • Skid control ECU
↑ 224 Front wheel cylinder pressure sensor RH output (PFR) is less than 0.33 V or more 0.85 V or more when not braking. ↑
↑ 225 The PFR output voltage is stuck at 4.53 V or less. ↑
↑ 227 Sensor power source 2 (VCM2) voltage is less than 4.7 V or 5.3 V or more for at least 0.05 seconds.

  • Wheel cylinder pressure sensor power supply

  • Brake actuator

  • Skid control ECU
↑ 228 Front wheel cylinder pressure sensor LH output voltage (PFL) is less than 0.25 V or 4.53 V or more for at least 0.05 seconds.

  • Wheel cylinder pressure sensor

  • Wheel cylinder pressure sensor circuit

  • Brake actuator

  • Skid control ECU
↑ 230 Front wheel cylinder pressure sensor LH output (PFL) is less than 0.33 V or 0.85 V or more when not braking. ↑
↑ 231 The PFL output voltage is stuck at 4.53 V or less. ↑
↑ 233 Sensor power source 2 (VCM2) voltage is less than 4.7 V or 5.3 V or more for at least 0.05 seconds.

  • Wheel cylinder pressure sensor power supply

  • Brake actuator

  • Skid control ECU
↑ 234 Rear wheel cylinder pressure sensor RH output voltage (PRR) is less than 0.25 V or 4.53 V or more for at least 0.05 seconds.

  • Wheel cylinder pressure sensor

  • Wheel cylinder pressure sensor circuit

  • Brake actuator

  • Skid control ECU
↑ 236 Rear wheel cylinder pressure sensor RH output (PRR) is less than 0.33 V or 0.85 V or more when not braking. ↑
↑ 237 The PRR output voltage is stuck at 4.53 V or less. ↑
↑ 239 Sensor power source 1 (VCM1) voltage is less than 4.7 V or 5.3 V or more for at least 0.05 seconds.

  • Wheel cylinder pressure sensor power supply

  • Brake actuator

  • Skid control ECU
↑ 240 Rear wheel cylinder pressure sensor LH output voltage (PRL) is less than 0.25 V or 4.53 V or more for at least 0.05 seconds.

  • Wheel cylinder pressure sensor

  • Wheel cylinder pressure sensor circuit

  • Brake actuator

  • Skid control ECU
↑ 242 Rear wheel cylinder pressure sensor LH output (PRL) is less than 0.33 V or 0.85 V or more when not braking. ↑
↑ 243 The PRL output voltage is stuck at 4.53 V or less. ↑
C1281/81 - Detected only during test mode.

  • Master cylinder pressure sensor

  • Master cylinder pressure sensor circuit

  • Stop light switch circuit

  • Brake actuator

WIRING DIAGRAM

A01GNU7E04

INSPECTION PROCEDURE

Note

When replacing the skid control ECU or brake actuator, perform initialization of linear solenoid valve and calibration Click here.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE ACTUATOR)


    1. Disconnect the A19 and A21 ECU connectors.

    2. Disconnect the A27 actuator connector.

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

      Standard resistance
      for LHD
      Tester Connection Condition Specified Condition
      A19-9 (PCK1) - A27-37 (PCK1) Always Below 1 Ω
      A19-14 (PMC1) - A27-38 (PMC1) Always Below 1 Ω
      A19-26 (PAC1) - A27-46 (PAC1) Always Below 1 Ω
      A19-27 (VCM) - A27-35 (VCM) Always Below 1 Ω
      A19-42 (PRL) - A27-36 (PRL) Always Below 1 Ω
      A19-28 (E) - A27-45 (E) Always Below 1 Ω
      A19-44 (PFR) - A27-34 (PFR) Always Below 1 Ω
      A21-7 (PCK2) - A27-42 (PCK2) Always Below 1 Ω
      A21-14 (PMC2) - A27-43 (PMC2) Always Below 1 Ω
      A21-28 (VCM2) - A27-40 (VCM2) Always Below 1 Ω
      A21-43 (PRR) - A27-41 (PRR) Always Below 1 Ω
      A21-44 (E2) - A27-44 (E2) Always Below 1 Ω
      A21-45 (PFL) - A27-39 (PFL) Always Below 1 Ω
      for RHD
      Tester Connection Condition Specified Condition
      A19-9 (PCK1) - A27-12 (PCK1) Always Below 1 Ω
      A19-14 (PMC1) - A27-13 (PMC1) Always Below 1 Ω
      A19-26 (PAC1) - A27-15 (PAC1) Always Below 1 Ω
      A19-27 (VCM) - A27-10 (VCM) Always Below 1 Ω
      A19-42 (PRL) - A27-11 (PRL) Always Below 1 Ω
      A19-28 (E) - A27-14 (E) Always Below 1 Ω
      A19-44 (PFR) - A27-9 (PFR) Always Below 1 Ω
      A21-7 (PCK2) - A27-7 (PCK2) Always Below 1 Ω
      A21-14 (PMC2) - A27-8 (PMC2) Always Below 1 Ω
      A21-28 (VCM2) - A27-5 (VCM2) Always Below 1 Ω
      A21-43 (PRR) - A27-6 (PRR) Always Below 1 Ω
      A21-44 (E2) - A27-16 (E2) Always Below 1 Ω
      A21-45 (PFL) - A27-4 (PFL) Always Below 1 Ω

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

      Standard resistance
      Tester Connection Condition Specified Condition
      A19-9 (PCK1) - Body ground Always 10 kΩ or higher
      A19-14 (PMC1) - Body ground Always 10 kΩ or higher
      A19-26 (PAC1) - Body ground Always 10 kΩ or higher
      A19-27 (VCM) - Body ground Always 10 kΩ or higher
      A19-42 (PRL) - Body ground Always 10 kΩ or higher
      A19-28 (E) - Body ground Always 10 kΩ or higher
      A19-44 (PFR) - Body ground Always 10 kΩ or higher
      A21-7 (PCK2) - Body ground Always 10 kΩ or higher
      A21-14 (PMC2) - Body ground Always 10 kΩ or higher
      A21-28 (VCM2) - Body ground Always 10 kΩ or higher
      A21-43 (PRR) - Body ground Always 10 kΩ or higher
      A21-44 (E2) - Body ground Always 10 kΩ or higher
      A21-45 (PFL) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. READ VALUE USING INTELLIGENT TESTER (MASTER CYLINDER PRESSURE SENSOR)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

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

      Skid control ECU:
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Master Cylinder Sensor Master cylinder pressure sensor 1 reading / min.: 0.00 V, max.: 5.00 V

      When brake pedal is released:

      0.30 to 0.90 V

      		 Reading increases when brake pedal is depressed
      Master Cylinder Sensor2 Master cylinder pressure sensor 2 reading / min.: 0.00 V, max.: 5.00 V

      When brake pedal is released:

      0.30 to 0.90 V

      		 Reading increases when brake pedal is depressed

    4. Check the output value of the master cylinder pressure sensor on the intelligent tester display.

      OK
      When the pedal is depressed, the voltage displayed on the intelligent tester increases.

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    OK

  3. CHECK PRESSURE SENSOR OPERATION


    1. Check the pressure sensor operation Click here for LHD, Click here for RHD).


    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    OK

  4. RECONFIRM DTC


    1. Clear the DTC Click here.

    2. Perform the road and braking test.

    3. Check if the same DTCs are recorded Click here.

      Tech Tips

      Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

      Result
      Result Proceed to
      DTCs (C1246/46 and C1364/61) are output A
      DTCs (C1246/46 and C1364/61) are not output B

    B

    END

    A

  5. CHECK FREEZE FRAME DATA


    1. Check the information code from the "FREEZE FRAME DATA" memorized when the DTCs (C1246/46 and C1364/61) are stored Click here.

      Result
      Result Proceed to
      Sensor power supply malfunction codes (191, 194, 221, 227, 233 and 239) are output A
      Sensor output malfunction codes (except 191, 194, 221, 227, 233 and 239) are output B

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    A

    REPLACE SKID CONTROL ECU Click here