ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1365/54

DTC Code DTC Name
C1365/54 Accumulator Pressure Sensor Malfunction

DESCRIPTION

The accumulator pressure sensor is built into the brake actuator.

The skid control ECU detects the accumulator pressure from the data sent from the accumulator pressure sensor, and then runs and stops the pump motor by operating the motor relay.

DTCs may be output if the accumulator pressure drops due to frequent braking (this is not a malfunction).

DTC Code INF Code DTC Detection Condition Trouble Area
C1365/54 211 Sensor power 1 (VCM) voltage is 4.7 V or less or 5.3 V or more for at least 0.05 seconds.

  • Brake actuator assembly (Accumulator pressure sensor)

  • Accumulator pressure sensor circuit

  • Accumulator pressure sensor power supply

  • Brake actuator assembly

  • Skid control ECU
↑ 212 Accumulator pressure sensor output voltage (PAC1) is less than 0.25 V or 4.53 V or more for at least 0.05 seconds. ↑
↑ 214 While the motor is off, the total of the wheel cylinder pressure sensor values of all 4 wheels increases but the accumulator pressure changes little for 0.5 seconds or more. ↑
↑ 215 Accumulator pressure sensor output voltage (PAC1) is stuck at 4.53 V or less. ↑

WIRING DIAGRAM

Refer to DTCs C1246/46, C1281/81 and C1364/61 Click here.

INSPECTION PROCEDURE

Note

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

PROCEDURE


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


    1. A01NGTJE05
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)
      *2

      Front view of wire harness connector

      (to Brake Actuator)

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

    2. Disconnect the skid control ECU connector and the brake actuator connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A89-8 (E) - A82-45 (E) Always Below 1 Ω
      A89-8 (E) - Body ground Always 10 kΩ or higher
      A89-9 (VCM) - A82-35 (VCM) Always Below 1 Ω
      A89-9 (VCM) - Body ground Always 10 kΩ or higher
      A89-21 (PAC1) - A82-46 (PAC1) Always Below 1 Ω
      A89-21 (PAC1) - Body ground Always 10 kΩ or higher
      A89-31 (PCK1) - A82-37 (PCK1) Always Below 1 Ω
      A89-31 (PCK1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT SKID CONTROL ECU (SENSOR OUTPUT)


    1. A01NDO9E29
      Text in Illustration
      *1

      Component without harness connected

      (Skid Control ECU)

      Reconnect the skid control ECU connector and the brake actuator connector.

    2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A89-9 (VCM) - Body ground Power switch on (IG) 4.75 to 5.25 V

    NG

    REPLACE SKID CONTROL ECU Click here

    OK

  3. INSPECT SKID CONTROL ECU (SENSOR INPUT)


    1. A01NDO9E30
      Text in Illustration
      *1

      Component without harness connected

      (Skid Control ECU)

      Depress the brake pedal to operate the pump motor, and then check that the pump motor stops.

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

      Note

      Do not depress the brake pedal until the pump motor stops and the voltage check is finished in order to keep the accumulator pressure.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A89-21 (PAC1) - Body ground Power switch on (IG) 3 to 4.7 V

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    OK

  4. READ VALUE USING INTELLIGENT TESTER (ACCUMULATOR PRESSURE SENSOR)


    1. Turn the power switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the power switch on (IG).

    4. Select the Data List on the intelligent tester Click here.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Accumulator Sensor

      Accumulator pressure sensor /

      Min.: 0 V, Max.: 5 V

      		 Specified value: 2.6 to 3.8 V When brake fluid is stored in the accumulator: Accumulator pressure changes in accordance with volume of fluid stored in the accumulator

    5. Depress the brake pedal 4 or 5 times to operate the pump motor, and check the output value on the intelligent tester with the motor stopped (brake pedal not depressed).

      OK
      Accumulator pressure sensor voltage does not drop.

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    OK

  5. RECONFIRM DTC


    1. Turn the power switch off.

    2. Clear the DTCs Click here.

    3. Perform a road test.

    4. Check if the same DTC is recorded Click here.

      Result
      Result Proceed to
      DTC (C1365/54) is not output A
      DTC (C1365/54) is output B

    B

    REPLACE SKID CONTROL ECU Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here