RX400h · Service Manual BRAKE

C1365/54

Diagnostic trouble codes

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).
DTC No.
 INF Code
 DTC Detecting Condition
 Trouble Area
C1365/54
 211
 Sensor power 1 (VCM1) voltage is 4.7 V or less or 5.3 V or more for at least 0.05 sec.
  1. Brake actuator assembly (accumulator pressure sensor)
  2. Brake actuator assembly (accumulator pressure sensor) circuit
  3. Skid control ECU
C1365/54
 212
 Ratio of accumulator pressure sensor output voltage (PACC) to sensor power 1 (VCM1) voltage is 5% or less or 90.5% or more for at least 0.05 sec.
  1. Brake actuator assembly (accumulator pressure sensor)
  2. Brake actuator assembly (accumulator pressure sensor) circuit
  3. Skid control ECU
C1365/54
 214
 Total wheel cylinder pressure sensor exceeds 12 MPa after depressing brake pedal, but accumulator pressure sensor output voltage (PACC) changes less than 0.5 MPa for at least 0.5 sec.
  1. Brake actuator assembly (accumulator pressure sensor)
  2. Brake actuator assembly (accumulator pressure sensor) circuit
  3. Skid control ECU
C1365/54
 215
 Ratio of accumulator pressure sensor output voltage (PACC) to sensor power 1 (VCM1) voltage is 90.5% or less for at least 0.1 sec. during self-diagnosis.
  1. Brake actuator assembly (accumulator pressure sensor)
  2. Brake actuator assembly (accumulator pressure sensor) circuit
  3. Skid control ECU
C1365/54
 216
 Voltage difference is 0.3 V or more before and after changing the pull up resistance in sensor signal input circuit (loose contact).
  1. Brake actuator assembly (accumulator pressure sensor)
  2. Brake actuator assembly (accumulator pressure sensor) circuit
  3. Skid control ECU

WIRING DIAGRAM

Refer to DTCs C1246/46 and C1364/61 (Click here).

INSPECTION PROCEDURE

NOTICE:
When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration (Click here).


1. CHECK HARNESS AND CONNECTOR (BETWEEN SKID CONTROL ECU AND BRAKE ACTUATOR ASSEMBLY)

  1. F047492E07
    Disconnect the skid control ECU connector and brake actuator connector.

  1. Measure the resistance according to the value(s) in the table below.

    Resistance:
    Tester Connection
    		 Specified Condition
    S41-8 (E) - B18-14 (E1)
    		 Below 1 Ω
    S41-9 (VCM) - B18-10 (VCM1)
    		 Below 1 Ω
    S41-21 (PAC1) - B18-15 (PACC)
    		 Below 1 Ω
    S41-31 (PCK1) - B18-12 (PCK1)
    		 Below 1 Ω

  1. Measure the resistance according to the value(s) in the table below.

    Resistance:
    Tester Connection
    		 Specified Condition
    S41-8 (E) - Body ground
    		 10 kΩ or higher
    S41-9 (VCM) - Body ground
    		 Below 1 Ω
    S41-21 (PAC1) - Body ground
    		 Below 1 Ω
    S41-31 (PCK1) - Body ground
    		 Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


2. INSPECT SKID CONTROL ECU (VCM TERMINAL)

  1. F047485E28
    Measure the voltage according to the value(s) in the table below.

    HINT:
    Measure the voltage from the back side of the connector with the connector connected to the skid control ECU.

    Voltage:
    Tester Connection
    		 Condition
    		 Specified Condition
    S41-9 (VCM) - S41-1 (GND1)
    		 Ignition switch ON
    		 4.75 to 5.25 V



NG
REPLACE SKID CONTROL ECU
OK


3. INSPECT SKID CONTROL ECU (PACC TERMINAL)

  1. F047485E29
    Check the auxiliary battery voltage.

    Voltage:
    10 to 14 V

  1. Depress the brake pedal to operate the pump motor, and then check that the pump motor stops.

  1. Measure the voltage according to the value(s) in the table below.

    Voltage:
    Tester Connection
    		 Specified Condition
    S41-21 (PAC1) - S41-1 (GND1)
    		 3.3 to 4.7 V

    NOTICE:
    1. Do not depress the brake pedal until the pump motor stops and the voltage check is finished in order to keep the accumulator pressure.
    2. Check from the back side of the connector with the connector connected to the skid control ECU.
    3. Do not use a DATA LIST, as the sensor itself must be checked.



 NG
REPLACE BRAKE ACTUATOR ASSEMBLY
OK


4. READ VALUE OF INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch on.

  1. Select the DATA LIST mode on the intelligent tester.

    ABS / VSC / TRAC: 
    Item
    		 Measurement Item /
    Range (Display)
    		 Normal Condition
    Accumulator Sensor
    		 Accumulator pressure sensor /
    min.: 0 V, max.: 5 V
    		 Specified value: 3.2 to 4.0 V

  1. Depress the brake pedal 4 or 5 times to operate the pump motor, and check the output value on the intelligent tester with the motor stopped (no braking).

    OK:
    Accumulator (ACC) pressure sensor voltage does not drop.



 NG
REPLACE BRAKE ACTUATOR ASSEMBLY
OK

REPLACE SKID CONTROL ECU


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