C1391

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

DTC C1391/69 - Accumulator Leak Malfunction

DESCRIPTION

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

INSPECTION PROCEDURE
NOTE: When replacing the brake actuator assembly, perform initialization and calibration of the linear solenoid valve. Initialization

PROCEDURE

1. CHECK FOR FLUID LEAK

(a) Check that there is no fluid leakage in the brake line between the brake actuator and the wheel cylinder which is indicated by 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. RECONFIRM DTC
(a) Clear the DTCs.
(b) Turn the power switch on (READY).
(c) Check if the same DTC is recorded.
Result:

B -- REPLACE BRAKE ACTUATOR ASSEMBLY
A -- Continue to next step.
3. READ VALUE USING TECHSTREAM (PRESSURE SENSOR)
(a) Turn the power switch off.
(b) Connect the Techstream to the DLC3.
(c) Turn the power switch on (IG).
(d) Select the Data List mode on the Techstream. Data List / Active Test

ABS / VSC / TRAC:

(e) Select the Active Test mode on the Techstream. Data List / Active Test
HINT: The Active Test can be performed when the following conditions are met.
- ABS main relays 1 and 2 are on.
- Shift lever is in P.
- Parking brake is applied.
- Vehicle speed is 0 km/h (0 mph).

ABS / VSC / TRAC:

*: Electronically Controlled Brake System
(f) Perform the Active Test of the solenoid using the Techstream.

(g) Check that the output value of each wheel cylinder does not increase.
OK:
The output value of each wheel cylinder does not increase.
HINT: If any output value increases, there may be a brake fluid leak in the brake actuator.

Result:

B -- REPLACE BRAKE BOOSTER PUMP
A -- REPLACE BRAKE ACTUATOR AND BRAKE BOOSTER PUMP ASSEMBLY