VEHICLE STABILITY CONTROL SYSTEM (for Hydraulic Brake Booster), Diagnostic DTC:C1256

DTC Code DTC Name
C1256 Accumulator Low Pressure

DESCRIPTION

Refer to DTC C1254 Click here.

DTC Code DTC Detection Condition Trouble Area
C1256 The fluid pressure inside the accumulator is below the standard value.
  • Hydraulic circuit

  • Master cylinder solenoid (Accumulator pressure sensor)

INSPECTION PROCEDURE

Note

When replacing the master cylinder solenoid, perform calibration Click here.

Tech Tips

When DTC C1251, C1253, or C1254 is output together with DTC C1256 inspect and repair the trouble area indicated by DTC C1251, C1253, or C1254 first.

PROCEDURE


  1. RECONFIRM DTC


    1. Clear the DTCs Click here.

    2. Turn the ignition switch off.

    3. Depress the brake pedal more than 40 times.

    4. Turn the ignition switch to ON.

    5. Wait for 99 seconds.

    6. Check if the same DTC is output Click here.

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

      Tech Tips

      Excessive brake pedal operation results in abnormal accumulator pressure consumption. This is normal.


    B
    A
  2. CHECK HYDRAULIC CIRCUIT


    1. Check the hydraulic circuit Click here.

      OK
      Hydraulic circuit is normal (no leakage).

    NG
    OK
  3. READ VALUE USING INTELLIGENT TESTER (ACCUMULATOR SENSOR)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Accumulator Sensor Accumulator pressure sensor reading/ Min.: 0.00 V, Max.: 5.00 V 3.58 to 5 V If the value is constant regardless of the pump operation, an accumulator pressure sensor malfunction is suspected.
    5. Check that the accumulator output value is normal.

      OK
      Accumulator pressure sensor value is normal.
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    B
    C
    A
  4. RECONFIRM DTC


    1. Clear the DTCs Click here.

    2. Check if the same DTC is output Click here.

      Result
      Result Proceed to
      DTC is not output A
      DTC is output (for LHD) B
      DTC is output (for RHD) C

    B
    C
    A