C1391

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

DTC C1391/69 - Accumulator Leak Malfunction

DESCRIPTION

The DTC is stored if a brake fluid or 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
NOTICE:
When replacing the skid control ECU or brake actuator assembly, perform initialization of linear solenoid valve and calibration Programming and Relearning.

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) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Select the Data List mode on the Techstream.

ABS / VSC / TRAC:





(d) Wait a few minutes without operating the brake pedal.
(e) Check that the output value of the accumulator pressure sensor does not decrease and that the pump motor is not activated due to a decrease in accumulator pressure.
OK:
Accumulator pressure does not decrease and the pump motor is not activated due to a decrease in accumulator pressure.
NG -- REPLACE BRAKE ACTUATOR ASSEMBLY
OK -- Continue to next step.
3. RECONFIRM DTC
(a) Clear the DTC Electronically Controlled Brake System.
(b) Turn the engine switch on (IG).
(c) Check if the same DTC is recorded Electronically Controlled Brake System.
Result:






B -- REPLACE SKID CONTROL ECU
A -- END