DTC    C1391/69    Accumulator Leak Malfunction

for Preparation Click here


DESCRIPTION

The DTC is stored if internal or external brake fluid leaks are detected due to improper sealing in the brake actuator or brake booster pump. Internal leaks are suspected if the pump motor operates frequently without braking.

DTC Code
INF Code
DTC Detection Condition
Trouble Area
C1391/69
351
Either of the following is detected:
  1. Accumulator pressure sensor input does not increase before braking or while the pump motor is operating.
  2. Accumulator pressure sensor input reduction rate exceeds the specification before braking and while the pump motor is not operating.
  1. Brake fluid leaks
  2. Brake booster with master cylinder (Brake actuator)
    (Malfunctioning internal seal, low gas pressure in accumulator, etc.)

INSPECTION PROCEDURE

NOTICE:
When replacing the brake booster with master cylinder (brake actuator), perform initialization and calibration of the linear solenoid valve (Click here).

1.CHECK FOR FLUID LEAK

  1. Check that there is no fluid leaks in the brake line between the brake actuator and the wheel cylinder which is indicated by DTCs.

  1. Check that the brake is not dragging.

    OK:
    There is no fluid leaks or dragging.



NG
REPAIR OR REPLACE APPLICABLE PART
OK


2.RECONFIRM DTC

  1. Clear the DTCs (Click here).

  1. Turn the power switch on (READY).

  1. Check if the same DTC is recorded (Click here).

    Result:

    Result
    		Proceed to
    DTC (C1391/69) is output
    		A
    DTC (C1391/69) is not output (for LHD)
    		B
    DTC (C1391/69) is not output (for RHD)
    		C



B
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)

C
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)
A


3.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (SOLENOID VALVE)

  1. Turn the power switch off.

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Select the Active Test on the intelligent tester (Click here).

    HINT:
    The Active Test can be performed when the following conditions are met.
    1. ABS main relay is on.
    2. Park (P) is selected.
    3. Parking brake is applied.
    4. Vehicle speed is 0 km/h (0 mph).


    ABS/VSC/TRC 
    Tester Display
    		Test Part
    		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
    *: Electronically Controlled Brake System

  1. Perform the Active Test of the solenoid using the intelligent tester.

  1. Select the Data List on the intelligent tester (Click here).


ABS/VSC/TRC 
Tester Display
Measurement Item/Range
Normal Condition
Diagnostic Note
Wheel Cylinder Pressure Sensor
Wheel cylinder pressure sensor / Min.: 0 V, Max.: 5 V
When brake pedal released: 0.1 to 0.9 V
Reading increases when brake pedal is depressed

  1. Check that the output value of the wheel cylinder does not increase.

    OK:
    The output value of the wheel cylinder does not increase.

    HINT:
    If any output value increases, there may be brake fluid leaks in the brake actuator.


    Result:

    Result
    		Proceed to
    The output value of the wheel cylinder increases
    		A
    The output values of the wheel cylinders do not increase
    		B



B
REPLACE BRAKE BOOSTER PUMP (Click here)
A


4.REPLACE BRAKE BOOSTER WITH MASTER CYLINDER

  1. Replace the brake booster with master cylinder (brake actuator) (Click here for LHD or Click here for RHD).


NEXT

REPLACE BRAKE BOOSTER PUMP (Click here)