Accumulator Pressure Sensor Malfunction - Electronically Controlled Brake System

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1365/54: Accumulator Pressure Sensor Malfunction

DTC C1365/54 - Accumulator Pressure Sensor Malfunction

DESCRIPTION

The accumulator (ACC) pressure sensor is built into the brake actuator.
The skid control ECU detects the accumulator pressure from the data sent from the accumulator pressure sensor, and then runs and stops the pump motor by operating the motor relay.
DTCs may be output if the accumulator pressure drops due to frequent braking (this is not a malfunction).






WIRING DIAGRAM





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

PROCEDURE

1. CHECK WIRE HARNESS (SKID CONTROL ECU - BRAKE ACTUATOR)




(a) Disconnect the S7 ECU connector.
(b) Disconnect the A2 actuator connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.

2. CHECK SKID CONTROL ECU (VCM1 VOLTAGE)




(a) Measure the voltage of the connector.
HINT: Measure the voltage from behind the connector with the connector connected to the skid control ECU.

Standard voltage:






NG -- REPLACE SKID CONTROL ECU
OK -- Continue to next step.

3. CHECK SKID CONTROL ECU (PACC VOLTAGE)
(a) Check the auxiliary battery voltage.
Standard voltage:
10 to 14 V
(b) Depress the brake pedal to operate the pump motor, and then check that the pump motor stops.




(c) Measure the voltage of the connector.
Standard voltage:





NOTICE:
- Do not depress the brake until after the pump motor stops and the voltage check is finished in order to keep the accumulator pressure.
- Check from behind the connector with the connector connected to the skid control ECU.
- Do not use a Data List, as the sensor itself must be checked.

NG -- REPLACE BRAKE ACTUATOR ASSEMBLY
OK -- Continue to next step.

4. 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 (no braking).

ABS / VSC / TRAC:





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