C1391

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1391/69: Accumulator Leak Malfunction

DTC C1391/69 - Accumulator Leak Malfunction

DESCRIPTION
HINT: The DTC is stored if a brake fluid, internal or other leak is detected due to improper sealing in the actuator. Internal leakage is suspected if the pump motor operates frequently without braking.





INSPECTION PROCEDURE
NOTE: When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration Initialization.

PROCEDURE

1. CHECK BRAKE FLUID LEAKAGE
(a) Check that there is no fluid leakage in the brake line between the brake actuator and the wheel cylinder which is the cause of DTCs.
(b) Check that the brake is not dragging.
OK:
There is no fluid leakage or dragging.
NG -- REPAIR OR REPLACE APPLICABLE PART
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM (ACCUMULATOR PRESSURE SENSOR)
(a) Check the Data List for proper functioning of the accumulator pressure sensor.
(b) Depress the brake pedal 4 or 5 times to operate the pump motor, and check the output value on Techstream with the motor and check the output value on Techstream with the motor stopped (no braking).

ABS / VSC / TRAC:





OK:
Accumulator pressure sensor voltage does not drop.
NG -- REPLACE BRAKE ACTUATOR ASSEMBLY
OK -- REPLACE SKID CONTROL ECU