LEMON Manuals: Even more car manuals for everyone
Home >> Toyota >> 2019 >> Mirai >> Repair and Diagnosis >> Brakes >> Mechanical - Hydraulic >> Electronically Controlled Brake System - Diagnostic Codes (2 Of 2) & Circuit Tests >> Electronically Controlled Brake System >> DTC C1391-69: Accumulator Leak Malfunction [06/2015 - ] >> Procedure

DTC C1391-69: Accumulator Leak Malfunction [06/2015 - ]: Procedure

  1. CHECK FOR FLUID LEAK 
    1. Check that there are no fluid leaks in the brake lines between the brake actuator (brake booster with master cylinder assembly) and the wheel cylinders.
    2. Check that the brakes are not dragging.

      OK

      There are no fluid leaks or dragging.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE APPLICABLE PART 

    Result: 

    OK 

    See step  2

  2. RECONFIRM DTC 
    1. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [06/2015 - ]

      Chassis > ABS/VSC/TRAC > Clear DTCs 

    2. Turn the power switch off.
    3. Turn the power switch on (READY).
    4. Check if the same DTC is output.

      Refer to DTC CHECK / CLEAR [06/2015 - ]

      Chassis > ABS/VSC/TRAC > Trouble Codes 

      Result

      Result Proceed to
      DTC C1391/69 is output. A
      DTC C1391/69 is not output. B

    Result: 

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to  REMOVAL [06/2015 - 11/2018]  , or refer to  REMOVAL [11/2018 - ] 

    Result: 

    See step  3

  3. PERFORM ACTIVE TEST USING TECHSTREAM (SOLENOID VALVE) 
    1. Turn the power switch off.
    2. Connect the Techstream to the DLC3.
    3. Turn the power switch on (IG).
    4. Select the Active Test on the Techstream.

      Refer to DATA LIST / ACTIVE TEST [06/2015 - ]

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      ECB Solenoid (SMC/SRC/SCC) Switching solenoid valve (SMC/SRC/SCC) Solenoid ON/OFF
      • Operation sound of solenoid (clicking sound) can be heard
      • ECB: Electronically Controlled Brake System

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display
      ECB Solenoid (SMC/SRC/SCC)

      HINT: 

      The Active Test can be performed when the following conditions are met.

      • ABS main relay is on.
      • Shift lever is in P.
      • Parking brake is applied.
      • Vehicle speed is 0 km/h (0 mph).
    5. Perform the Active Test of the solenoid using the Techstream.
    6. Select the Data List on the Techstream.

      Refer to DATA LIST / ACTIVE TEST [06/2015 - ]

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Wheel Cylinder Pressure Sensor Wheel cylinder pressure sensor Min.: 0.00 V, Max.: 5.00 V Brake pedal released: 0.10 to 0.90 V Reading increases when brake pedal is depressed

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display
      Wheel Cylinder Pressure Sensor
    7. Check that the output value of the wheel cylinder pressure sensor does not increase.

      OK

      The output value of the wheel cylinder pressure sensor does not increase.

      HINT: 

      If the output value increases, there may be brake fluid leaks in the brake actuator (brake booster with master cylinder assembly).

      Result

      Result Proceed to
      The output value of the wheel cylinder pressure sensor increases. A
      The output values of the wheel cylinder pressure sensor does not increase. B

    Result: 

    REPLACE BRAKE BOOSTER PUMP ASSEMBLY. Refer to  REMOVAL [06/2015 - 11/2018]  , or refer to  REMOVAL [11/2018 - ] 

    Result: 

    See step  4

  4. REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY 
    1. Replace the brake actuator (brake booster with master cylinder assembly).

      Refer to REMOVAL [06/2015 - 11/2018] , or refer to REMOVAL [11/2018 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    REPLACE BRAKE BOOSTER PUMP ASSEMBLY. Refer to  REMOVAL [06/2015 - 11/2018]  , or refer to  REMOVAL [11/2018 - ]