DTC    C1252/52    Brake Booster Pump Motor on Time Abnormally Long

DTC    C1253/53    Hydro Booster Pump Motor Relay Malfunction

for Preparation Click here


DESCRIPTION

The skid control ECU detects decreases in the accumulator pressure according to the data from the accumulator pressure sensor, and then starts and stops the pump motor by operating the motor relay.
The skid control ECU usually drives the motor relay 1 for ECB control, and the motor relay 2 for ABS control.
If either is malfunctioning, the will other substitute.

DTC No.
INF Code
DTC Detecting Condition
Trouble Area
C1252/52
130
Motor relay is ON for at least 5 min.
  1. ABS MTR1 relay
  2. ABS MTR2 relay
  3. Brake actuator assembly
C1253/53
132
Motor relay 1 coil (monitor) is energized for at least 1 sec. when main relay 1 monitor (BS1) is 9.5 V or more and motor relay 1 is off.
  1. ABS MTR1 relay
  2. Wire harness or connector
C1253/53
133
Motor relay 1 coil (monitor) is not energized for at least 1 sec. when main relay 1 monitor (BS1) is 9.5 V or more and motor relay 1 is on.
  1. ABS MTR1 relay
  2. Wire harness or connector
C1253/53
134
MTT input is 3.5 V or less for at least 0.2 sec. when main relay 1 monitor (BS1) is 9.5 V or more and motor relay 1 is on.
  1. ABS MTR1 relay
  2. Wire harness or connector
  3. Brake actuator pump motor
  4. Brake actuator pump motor circuit
C1253/53
136
Motor relay 2 coil (monitor) is energized for at least 1 sec. when main relay 2 monitor (BS2) is 9.5 V or more and motor relay 2 is off.
  1. ABS MTR2 relay
  2. Wire harness or connector
C1253/53
137
Motor relay 2 coil (monitor) is not energized for at least 1 sec. (0.2 sec. during initial check) when main rely 2 monitor (BS2) is 9.5 V or more and motor relay 2 is on.
  1. ABS MTR2 relay
  2. Wire harness or connector
C1253/53
138
MTT input is 3.5 V or less for at least 1 sec. (0.2 sec. during initial check) when main relay 1 monitor (BS1) is 9.5 V or more and motor relay 2 is on.
  1. ABS MTR2 relay
  2. Wire harness or connector
  3. Brake actuator pump motor
  4. Brake actuator pump motor circuit
C1253/53
140
MTT input is 3.5 V or more for at least 2 sec. when motor relay 1 and 2 are off.
  1. ABS MTR1 relay
  2. ABS MTR2 relay
  3. Brake actuator pump motor
  4. Brake actuator pump motor circuit

WIRING DIAGRAM


C100607E04


INSPECTION PROCEDURE

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

1.PERFORM ACTIVE TEST BY INTELLIGENT TESTER (ECB MOTOR RELAY)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch on.

  1. Select the ACTIVE TEST mode on the intelligent tester.

  1. Check the operating sound of the ABS motor individually when operating it with the intelligent tester.

    ABS / VSC / TRAC: 
    Item
    		Measurement Item /
    Range (Display)
    		Normal Condition
    ECB Motor Relay
    		Turns ABS MTR1 Relay ON/OFF
    		Operating of solenoid
    (clicking sound) can be heard
    ECB Motor Relay 2
    		Turns ABS MTR 2 Relay ON/OFF
    		Operating of solenoid
    (clicking sound) can be heard

    OK:
    The operating sound of the ABS motor should be heard.



NG
Go to step 6
OK


Go to step 3

2.INSPECT FUSE (ABS MTR1 AND ABS MTR2 FUSES)


    F100413E01

  1. Remove the ABS MTR1 and ABS MTR2 fuses from the engine room R/B No.4.

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

    Resistance:
    Fuse
    		Specified Condition
    ABS MTR1
    		Below 1 Ω (Continuity)
    ABS MTR2
    		Below 1 Ω (Continuity)



NG
REPLACE FUSE
OK


Go to step 2

3.INSPECT BRAKE ACTUATOR ASSEMBLY


    F047491E01

  1. Disconnect the brake actuator assembly connector.

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

    Resistance:
    Tester Connection
    		Specified Condition
    32 (BM2) - 1 (GND1)
    		Below 10 Ω
    31 (BM1) - 1 (GND1)
    		Below 10 Ω
    32 (BM2) - 31 (BM1)
    		Below 1 Ω
    1 (GND1) - 2 (GND2)
    		Below 1 Ω
    32 (BM2) - 3 (MTT)
    		About 33 Ω
    31 (BM1) - 3 (MTT)
    		About 33 Ω



NG
REPLACE BRAKE ACTUATOR ASSEMBLY
OK


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


    F047492E05

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

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

    Resistance:
    Tester Connection
    		Specified Condition
    S41-29 (MTT) - B18-3 (MTT)
    		Below 1 Ω
    B18-1 (GND1) - Body ground
    		Below 1 Ω
    B18-2 (GND2) - Body ground
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.READ VALUE OF INTELLIGENT TESTER (ACCUMULATOR PRESSURE SENSOR)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch on.

  1. Select the DTA 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 (not braking).

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



NG
REPLACE BRAKE ACTUATOR ASSEMBLY
OK

REPLACE SKID CONTROL ECU 

6.INSPECT ABS MOTOR RELAY


    B057491

  1. Remove the ABS MTR1 relay and ABS MTR 2 relay.

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

    Resistance:
    Tester Connection
    		Connection
    		Specified Resistance
    3 - 5
    		Always
    		10 kΩ or higher
    (No continuity)
    3 - 5
    		Apply B+ between terminals 1 and 2
    		Below 1 Ω



NG
REPLACE ABS MOTOR RELAY
OK


7.CHECK HARNESS AND CONNECTOR (BETWEEN ENGINE ROOM R/B NO.4 AND BATTERY)


    C113972E01

  1. Remove the ABS MTR1 relay and ABS MTR 2 relay.

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

    Voltage:
    Tester Connection
    		Specified Condition
    ABS MTR1 Relay (5) - Body ground
    		10 to 14 V
    ABS MTR 2 Relay (5) - Body ground
    		10 to 14 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


8.CHECK HARNESS AND CONNECTOR (BETWEEN ENGINE ROOM R/B NO.4 AND BREAK ACTUATOR ASSEMBLY)


    C112024E03

  1. Disconnect the brake actuator assembly connector.

  1. Remove the ABS MTR1 relay and ABS MTR 2 relay.

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

    Resistance:
    Tester Connection
    		Specified Condition
    B18-32 (BM2) - ABS MTR 2 Relay (3)
    		Below 1 Ω
    B18-31 (BM1) - ABS MTR1 Relay (3)
    		Below 1 Ω

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

    Resistance:
    Tester Connection
    		Specified Condition
    A2-1 (BM2) - Body ground
    		10 kΩ or higher
    A2-2 (BM1) - Body ground
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


9.CHECK HARNESS AND CONNECTOR (BETWEEN ENGINE ROOM R/B NO.4 AND SKID CONTROL ECU)


    C112025E03

  1. Disconnect the skid control ECU connector.

  1. Remove the ABS MTR1 relay and ABS MTR2 relay.

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

    Resistance:
    Tester Connection
    		Specified Condition
    S41-11 (MR1) - ABS MTR1 Relay (2)
    		Below 1 Ω
    S41-25 (R1-) - ABS MTR1 Relay (1)
    		Below 1 Ω
    S38-25 (MR2) - ABS MTR 2 Relay (2)
    		Below 1 Ω
    S38-30 (R2-) - ABS MTR 2 Relay (1)
    		Below 1 Ω

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

    Resistance:
    Tester Connection
    		Specified Condition
    S41-11 (MR1) - Body ground
    		10 kΩ or higher
    S41-25 (R1-) - Body ground
    		10 kΩ or higher
    S38-25 (MR2) - Body ground
    		10 kΩ or higher
    S38-30 (R2-) - Body ground
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE SKID CONTROL ECU