Accumulator Low Pressure - Electronically Controlled Brake System

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1256/57: Accumulator Low Pressure

DTC C1256/57 - Accumulator Low Pressure

DESCRIPTION

The accumulator pressure sensor is built into the actuator and detects the accumulator pressure.
The skid control ECU turns on the brake control warning light and sounds the skid control buzzer if it senses a decrease in the accumulator pressure.






INSPECTION PROCEDURE
NOTE: When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration Initialization.
HINT: DTCs may be output if the accumulator pressure drops due to frequent braking (this is not a malfunction).

PROCEDURE

1. INSPECT BRAKE ACTUATOR ASSEMBLY




(a) Disconnect the brake actuator connector.
(b) Measure the resistance of the actuator.
Standard resistance:






NG -- REPLACE BRAKE ACTUATOR ASSEMBLY
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 stopped (not braking).

ABS / VSC / TRAC:





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