ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1252/52, C1253/53

DTC Code DTC Name
C1252/52 Brake Booster Pump Motor on Time Abnormally Long
C1253/53 Pump Motor Relay Malfunction

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 No. 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.)

  • Short in motor circuit or motor monitor circuit

  • Motor relay stuck

  • Accumulator pressure sensor malfunction in brake actuator (Brake booster with master cylinder assembly)

  • Skid control ECU (Brake booster with master cylinder assembly)
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.

  • Open in motor circuit or motor monitor circuit

  • Skid control ECU (Brake booster with master cylinder assembly)
↑ 322 The motor drive monitor remains on for 2 seconds or more after a motor drive off request.

  • Short in motor circuit or motor monitor circuit

  • Skid control ECU (Brake booster with master cylinder assembly)
↑ 323 The skid control ECU internal motor drive logical inconsistency continues for 2 seconds or more. Skid control ECU (Brake booster with master cylinder assembly)
↑ 324 An open circuit in both skid control ECU internal motor relays 1 and 2.

  • Open in motor circuit or motor monitor circuit

  • Skid control ECU (Brake booster with master cylinder assembly)
↑ 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

A01HT21E01

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING TECHSTREAM (ABS MOTOR RELAY)


    1. Connect the Techstream to the DLC3.

    2. Turn the power switch on (IG).

    3. Select the Active Test on the Techstream Click here.

      ABS/VSC/TRAC
      Tester Display Test Part Control Range Diagnostic Note
      ECB* Motor Relay ABS motor relay Relay ON/OFF -

      *: Electronically Controlled Brake System

    4. Select the Data List on the Techstream Click here.

      ABS/VSC/TRAC
      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

    5. Check the operating condition of the ABS motor relay when operating it using the Techstream.

      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

    CHECK HARNESS AND CONNECTOR (MRI TERMINAL) Click here

    A

  2. INSPECT BRAKE BOOSTER PUMP ASSEMBLY


    1. A01HTK7E14
      Text in Illustration
      *a

      Component without harness connected

      (Brake Booster Pump Assembly)

      Turn the power switch off.

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

    3. Disconnect the brake booster pump assembly connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A46-2 (BM1) - A46-4 (GND1) Always Below 10 Ω
      A47-2 (BM2) - A47-1 (GND2) Always Below 10 Ω
      A46-2 (BM1) - A47-2 (BM2) Always Below 1 Ω
      A46-4 (GND1) - A47-1 (GND2) Always Below 1 Ω

    NG

    REPLACE BRAKE BOOSTER PUMP ASSEMBLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (GND TERMINAL)


    1. A01HVOJE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Brake Booster Pump Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A46-4 (GND1) - Body ground Always Below 1 Ω
      A47-1 (GND2) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)

    OK

  4. READ VALUE USING TECHSTREAM (ACCUMULATOR PRESSURE SENSOR)


    1. Reconnect the brake booster pump assembly connectors.

    2. Connect the Techstream to the DLC3.

    3. Turn the power switch on (IG).

    4. Select the Data List on the Techstream Click here.

      ABS/VSC/TRAC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Accumulator Sensor

      Accumulator pressure sensor /

      Min.: 0.00 V, Max.: 5.00 V

      		 Specified value: 2.90 to 4.20 V When brake fluid is stored in the accumulator: Accumulator pressure changes in accordance with volume of fluid stored in the accumulator

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

    6. Check that the accumulator pressure sensor output value change is within the specified range.

      OK
      Accumulator pressure sensor output value change is less than 0.55 V.

    NG

    PERFORM ACTIVE TEST USING TECHSTREAM (SOLENOID VALVE) Click here

    OK

  5. RECONFIRM DTC


    1. Turn the power switch off.

    2. Clear the DTCs Click here.

    3. Turn the power switch on (IG).

    4. Check if the same DTC is output 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. B

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

  6. CHECK HARNESS AND CONNECTOR (MRI TERMINAL)


    1. A01HV5JE96
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

      Turn the power switch off.

    2. Check that the ABS MTR NO. 1 (50 A) and ABS MTR NO. 2 (50 A) fuses are normal.

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

    4. Disconnect the skid control ECU (brake booster with master cylinder assembly) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A28-1 (MRI1) - Body ground Always 11 to 14 V
      A28-2 (MRI2) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MRI CIRCUIT)

    OK

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


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

    2. Disconnect the brake booster pump assembly connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A28-29 (MRO1) - A46-2 (BM1) Always Below 1 Ω
      A28-29 (MRO1) - Body ground Always 10 kΩ or higher
      A28-30 (MRO2) - A47-2 (BM2) Always Below 1 Ω
      A28-30 (MRO2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

  8. PERFORM ACTIVE TEST USING TECHSTREAM (SOLENOID VALVE)


    1. Select the Active Test on the Techstream Click here.

      Tech Tips

      The Active Test can be performed when the following conditions are met.


      • ABS main relay is on.

      • Shift lever is in P.

      • Parking brake is applied.

      • Vehicle speed is 0 km/h (0 mph).

      ABS/VSC/TRAC
      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

    2. Perform the Active Test of the solenoid using the Techstream.

    3. Select the Data List on the Techstream Click here.

      ABS/VSC/TRAC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Wheel Cylinder Pressure Sensor Wheel cylinder pressure sensor / Min.: 0.00 V, Max.: 5.00 V When brake pedal released: 0.10 to 0.90 V Reading increases when brake pedal is depressed

    4. Check that the output value of the wheel cylinder pressure sensor does not increase.

      OK
      The output value of the wheel cylinder pressure sensor does not increase.

      Tech Tips

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


    NG

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

    OK

    REPLACE BRAKE BOOSTER PUMP ASSEMBLY Click here