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

DTC    C1253/53    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.

DTC Code
INF Code
DTC Detection Condition
Trouble Area
C1252/52
311
The pump motor is operating continuously for 178 seconds or more. (When relay malfunction is 98 seconds or more.)
  1. Short in motor circuit or motor monitor circuit
  2. Motor relay stuck
  3. Accumulator pressure sensor malfunction in brake actuator
  4. Brake booster with master cylinder (Skid control ECU)
C1253/53
321
With the IG1 terminal voltage 9.5 V or more, the motor drive monitor remains off for 0.2 seconds or more after a motor drive on request.
  1. Open in motor circuit or motor monitor circuit
  2. Brake booster with master cylinder (Skid control ECU)
↑
322
The motor drive monitor remains on for 2 seconds or more after a motor drive off request.
  1. Short in motor circuit or motor monitor circuit
  2. Brake booster with master cylinder (Skid control ECU)
↑
323
The skid control ECU internal motor drive logical inconsistency continues for 2 seconds or more.
Brake booster with master cylinder (Skid control ECU)
↑
324
An open circuit in both skid control ECU internal motor relays 1 and 2.
  1. Open in motor circuit or motor monitor circuit
  2. Brake booster with master cylinder (Skid control ECU)
↑
325
An open circuit in both skid control ECU internal motor relays 1 and 3.
↑
↑
326
An open circuit in both skid control ECU internal motor relays 2 and 3.
↑
↑
327
An open circuit in skid control ECU internal motor relay 1.
↑
↑
328
An open circuit in skid control ECU internal motor relay 2.
↑
↑
329
An open circuit in skid control ECU internal motor relay 3.
↑

WIRING DIAGRAM


C210622E01


INSPECTION PROCEDURE

NOTICE:
When replacing the brake booster with master cylinder (skid control ECU or brake actuator), perform initialization, calibration of the linear solenoid valve and emergency brake signal learning (Click here).

1.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (ABS MOTOR RELAY)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Select the Active Test on the intelligent tester (Click here).

    ABS/VSC/TRC 
    Tester Display
    		Test Part
    		Control Range
    		Diagnostic Note
    ECB* Motor Relay
    		ABS motor relay
    		Relay ON/OFF
    		-
    *: Electronically Controlled Brake System

  1. Select the Data List on the intelligent tester (Click here).


ABS/VSC/TRC 
Tester Display
Measurement Item/Range
Normal Condition
Diagnostic Note
ECB* Motor Relay
ABS motor relay / ON or OFF
ON: Relay on
OFF: Relay off
-
*: Electronically Controlled Brake System

  1. Check the operating condition of the ABS motor relay when operating it with the intelligent tester.

    Result:

    Result
    		Proceed to
    ABS motor relay in the Data List turns ON/OFF using the Active Test
    		A
    ABS motor relay in the Data List does not change using the Active Test
    		B



B
Go to step 6
A


2.INSPECT BRAKE BOOSTER PUMP


    C156574E01

  1. Turn the power switch off.

  1. Make sure that there is no looseness at the locking part and the connecting part of the connectors.

  1. Disconnect the brake booster pump connectors.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A17-1 (BM1) - A17-2 (GND1)
    		Always
    		Below 10 Ω
    A18-2 (BM2) - A18-1 (GND2)
    		Always
    		Below 10 Ω
    A17-1 (BM1) - A18-2 (BM2)
    		Always
    		Below 1 Ω
    A17-2 (GND1) - A18-1 (GND2)
    		Always
    		Below 1 Ω

    Text in Illustration 
    *1
    		Component without harness connected
    (Brake Booster Pump)



NG
REPLACE BRAKE BOOSTER PUMP (Click here)
OK


3.INSPECT BRAKE BOOSTER PUMP (GND TERMINAL)


    C210626E01

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A17-2 (GND1) - Body ground
    		Always
    		Below 1 Ω
    A18-1 (GND2) - Body ground
    		Always
    		Below 1 Ω

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Brake Booster Pump)



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)
OK


4.READ VALUE USING INTELLIGENT TESTER (ACCUMULATOR PRESSURE SENSOR)

  1. Reconnect the brake booster pump connectors.

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Select the Data List on the intelligent tester (Click here).

    ABS/VSC/TRC 
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    Accumulator Sensor
    		Accumulator pressure sensor /
    Min.: 0 V, Max.: 5 V
    		Specified value: 2.9 to 4.2 V
    		When brake fluid is stored in the accumulator: Accumulator pressure changes in accordance with volume of fluid stored in the accumulator

  1. Wait for 30 seconds without depressing the brake pedal.

  1. Check that the accumulator pressure sensor output values change is within the specified range.

    OK:
    Accumulator pressure sensor output values change is within 0.55 V.



NG
Go to step 9
OK


5.RECONFIRM DTC

  1. Turn the power switch off.

  1. Clear the DTCs (Click here).

  1. Turn the power switch on (IG).

  1. Check if the same DTC is recorded (Click here).

    Result:

    Result
    		Proceed to
    DTCs (C1252/52 and C1253/53) are not output
    		A
    DTCs (C1252/52 and/or C1253/53) are output (for LHD)
    		B
    DTCs (C1252/52 and/or C1253/53) are output (for RHD)
    		C



B
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)

C
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)
A

CHECK FOR INTERMITTENT PROBLEMS (Click here)  

6.INSPECT ABS MTR FUSES
C210280E02

  1. Turn the power switch off.

  1. Remove the ABS MTR fuses.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    ABS MTR1 (30 A) fuse
    		Always
    		Below 1 Ω
    ABS MTR2 (30 A) fuse
    		Always
    		Below 1 Ω

    Text in Illustration 
    *1
    		Engine Room Relay Block
    *2
    		ABS MTR1 Fuse
    *3
    		ABS MTR2 Fuse



NG
REPLACE ABS MTR FUSES
OK


7.INSPECT SKID CONTROL ECU (MRI TERMINAL)


    C209401E12

  1. Install the ABS MTR fuses.

  1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

  1. Disconnect the skid control ECU connector.

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    A58-1 (MRI1) - Body ground
    		Always
    		11 to 14 V
    A58-2 (MRI2) - Body ground
    		Always
    		11 to 14 V

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Skid Control ECU)



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (MRI CIRCUIT)
OK


8.CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE BOOSTER PUMP)


    C210625E01

  1. Make sure that there is no looseness at the locking part and the connecting part of the connectors.

  1. Disconnect the brake booster pump connectors.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A58-29 (MRO1) - A17-1 (BM1)
    		Always
    		Below 1 Ω
    A58-29 (MRO1) - Body ground
    		Always
    		10 kΩ or higher
    A58-30 (MRO2) - A18-2 (BM2)
    		Always
    		Below 1 Ω
    A58-30 (MRO2) - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Skid Control ECU)
    *2
    		Front view of wire harness connector
    (to Brake Booster Pump)

    Result:

    Result
    		Proceed to
    OK (for LHD)
    		A
    OK (for RHD)
    		B
    NG
    		C



B
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)

C
REPAIR OR REPLACE HARNESS OR CONNECTOR
A

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)  

9.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (SOLENOID VALVE)

  1. Select the Active Test on the intelligent tester (Click here).

    HINT:
    The Active Test can be performed when the following conditions are met.
    1. ABS main relay is on.
    2. Park (P) selected.
    3. Parking brake is applied.
    4. Vehicle speed is 0 km/h (0 mph).


    ABS/VSC/TRC 
    Tester Display
    		Test Part
    		Control Range
    		Diagnostic Note
    ECB* Solenoid (SMC/SRC/SCC)
    		Switching solenoid valve (SMC/SRC/SCC)
    		Solenoid ON/OFF
    		Operation sound of solenoid (clicking sound) can be heard
    *: Electronically Controlled Brake System

  1. Perform the Active Test of the solenoid using the intelligent tester.

  1. Select the Data List on the intelligent tester (Click here).


ABS/VSC/TRC 
Tester Display
Measurement Item/Range
Normal Condition
Diagnostic Note
Wheel Cylinder Pressure Sensor
Wheel cylinder pressure sensor / Min.: 0 V, Max.: 5 V
When brake pedal released: 0.1 to 0.9 V
Reading increases when brake pedal is depressed

  1. Check that the output value of wheel cylinder does not increase.

    OK:
    The output value of wheel cylinder does not increase.

    HINT:
    If any output value increases, there may be brake fluid leaks in the brake actuator.


    Result:

    Result
    		Proceed to
    OK
    		A
    NG (for LHD)
    		B
    NG (for RHD)
    		C



B
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)

C
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)
A

REPLACE BRAKE BOOSTER PUMP (Click here)