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.

The skid control ECU usually drives the motor relay 1 for electronically controlled brake system control, and the motor relay 2 for ABS control. If either of them is malfunctioning, the other will substitute.

DTC Code INF Code DTC Detection Condition Trouble Area
C1252/52 130 Motor relay is on for at least 3 minutes.
  • ECB* MTR1 relay

  • ECB* MTR1 relay circuit

  • ECB* MTR2 relay

  • ECB* MTR2 relay circuit

  • Brake booster pump (Accumulator)

C1253/53 134 MTT input is less than 3.5 V for at least 1 second or more when linear solenoid power source voltage 1 (BS1) is 9.5 V or more, either of +BI1 or +BI2 voltage is 7 V or more, and motor relay 1 is on.
  • Fusible link block (ECB* NO. 1 fuse)

  • ECB* MTR1 relay

  • ECB* MTR1 relay circuit

  • Brake booster pump (Pump motor)

  • Pump motor circuit

138 MTT input is less than 3.5 V for at least 1 second or more when linear solenoid power source voltage 2 (BS2) is 9.5 V or more, either of +BI1 or +BI2 voltage is 7 V or more, and motor relay 1 is on.
  • Fusible link block (ECB* NO. 2 fuse)

  • ECB* MTR2 relay

  • ECB* MTR2 relay circuit

  • Brake booster pump (Pump motor)

  • Pump motor circuit

140 MTT input is 3.5 V or more for at least 2 seconds when motor relay 1 and 2 are off.
  • ECB* MTR1 relay circuit

  • ECB* MTR2 relay circuit

  • Brake booster pump (Pump motor)

  • Pump motor circuit

*: Electronically Controlled Brake System

WIRING DIAGRAM

A01NFBTE02

INSPECTION PROCEDURE

Note

When replacing the skid control ECU or brake actuator assembly, perform initialization and calibration of the linear solenoid valve Click here.

PROCEDURE


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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. 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 Operation sound of relay (clicking sound) and motor can be heard
      ECB* Motor Relay2 ABS motor relay 2 Relay ON/OFF Operation sound of relay (clicking sound) and motor can be heard

      *: Electronically Controlled Brake System

    4. Check the operation sound of the ABS motor relay and motor when operating it using the intelligent tester.

      OK
      The operation sound of the ABS motor relay and motor should be heard.

    NG
    OK
  2. INSPECT BRAKE BOOSTER PUMP


    1. A01NECCE08
      Text in Illustration
      *1

      Component without harness connected

      (Brake Booster Pump)

      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 connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A83-2 (BM1) - A83-4 (GND1) Always Below 10 Ω
      A84-2 (BM2) - A83-4 (GND1) Always Below 10 Ω
      A83-2 (BM1) - A84-2 (BM2) Always Below 1 Ω
      A83-4 (GND1) - A84-1 (GND2) Always Below 1 Ω
      A83-2 (BM1) - A83-1 (MTT) Always 950 to 1050 Ω
      A84-2 (BM2) - A83-1 (MTT) Always 950 to 1050 Ω

    NG
    OK
  3. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE BOOSTER PUMP)


    1. A01NDU0E03
      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)

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

    2. Disconnect the skid control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A89-29 (MTT) - A83-1 (MTT) Always Below 1 Ω
      A89-29 (MTT) - Body ground Always 10 kΩ or higher
      A83-4 (GND1) - Body ground Always Below 1 Ω
      A84-1 (GND2) - Body ground Always Below 1 Ω

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


    1. Reconnect the skid control ECU connector and the brake booster pump connectors.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the power switch on (IG).

    4. 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: 2.6 to 3.8 V When brake fluid is stored in the accumulator: Accumulator pressure changes in accordance with volume of fluid stored in the accumulator
    5. 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 pressure sensor output voltage does not drop.

    NG
    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 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 B

    B
    A
  6. INSPECT ECB* NO. 1, 2 FUSE


    1. A01NFUNE05
      Text in Illustration
      *1 Engine Room Relay Block
      *2 ECB* NO. 1 Fuse
      *3 ECB* NO. 2 Fuse

      Turn the power switch off.

    2. Remove the fusible link block from the engine room relay block.

    3. Check if the fusible link is melted.

      OK
      The fusible link is not melted.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      ECB* NO. 1 (50 A) fuse - Body ground Always Below 1 Ω
      ECB* NO. 2 (50 A) fuse - Body ground Always Below 1 Ω

      *: Electronically Controlled Brake System


    NG
    OK
  7. INSPECT ABS MOTOR RELAY (ECB* MTR1, 2)


    1. A01NFAFE11
      Text in Illustration
      *1 ABS Motor Relay (ECB* MTR1, 2 Relay)

      Install the fusible link block to the engine room relay block .

    2. Remove the ECB* MTR1 relay and the ECB* MTR2 relay.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 Voltage is not applied between terminals 1 and 2 10 kΩ or higher
      3 - 5 Voltage is applied between terminals 1 and 2 Below 1 Ω

      *: Electronically Controlled Brake System


    NG
    OK
  8. INSPECT ENGINE ROOM NO. 2 RELAY BLOCK (POWER SOURCE TERMINAL)


    1. A01NG20E01
      Text in Illustration
      *1 Engine Room No. 2 Relay Block
      *2 ECB* MTR1 Relay
      *3 ECB* MTR2 Relay

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      ECB* MTR1 relay terminal 5 - Body ground Always 11 to 14 V
      ECB* MTR2 relay terminal 5 - Body ground Always 11 to 14 V

      *: Electronically Controlled Brake System


    NG
    OK
  9. CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER PUMP - ENGINE ROOM NO. 2 RELAY BLOCK)


    1. A01NCPJE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Brake Booster Pump)

      *2 Engine Room No. 2 Relay Block
      *3 ECB* MTR1 Relay
      *4 ECB* MTR2 Relay

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

    2. Disconnect the brake booster pump connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A83-2 (BM1) - ECB* MTR1 relay terminal 3 Always Below 1 Ω
      A83-2 (BM1) - Body ground Always 10 kΩ or higher
      A84-2 (BM2) - ECB* MTR2 relay terminal 3 Always Below 1 Ω
      A84-2 (BM2) - Body ground Always 10 kΩ or higher

      *: Electronically Controlled Brake System


    NG
    OK
  10. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - ENGINE ROOM NO. 2 RELAY BLOCK)


    1. A01NHIFE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)

      *2 Engine Room No. 2 Relay Block
      *3 ECB* MTR1 Relay
      *4 ECB* MTR2 Relay

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

    2. Disconnect the skid control ECU connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A89-11 (MR1) - ECB* MTR1 relay terminal 2 Always Below 1 Ω
      A89-11 (MR1) - Body ground Always 10 kΩ or higher
      A89-24 (R1-) - ECB* MTR1 relay terminal 1 Always Below 1 Ω
      A89-24 (R1-) - Body ground Always 10 kΩ or higher
      A92-14 (R2-) - ECB* MTR2 relay terminal 1 Always Below 1 Ω
      A92-14 (R2-) - Body ground Always 10 kΩ or higher
      A92-17 (MR2) - ECB* MTR2 relay terminal 2 Always Below 1 Ω
      A92-17 (MR2) - Body ground Always 10 kΩ or higher

      *: Electronically Controlled Brake System


    NG
    OK
  11. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (SOLENOID VALVE)


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

      Tech Tips

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


      • ABS main relays 1 and 2 are on.

      • Shift lever is in P.

      • Parking brake is applied.

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

      ABS/VSC/TRC
      Tester Display Test Part Control Range Diagnostic Note
      ECB* Solenoid (SMC1) Master cut solenoid (SMC1) Solenoid ON/OFF Operation sound of solenoid (clicking sound) can be heard
      ECB* Solenoid (SMC2) Master cut solenoid (SMC2) Solenoid ON/OFF Operation sound of solenoid (clicking sound) can be heard
      ECB* Solenoid (SLRRL) Value Close Linear solenoid (RLR) valve Valve close ON/OFF Operation sound of solenoid (clicking sound) can be heard
      ECB* Solenoid (SLRRR) Value Close Linear solenoid (RRR) valve Valve close 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 intelligent tester.

      A01NF5ME02
    3. Select the Data List on the intelligent tester Click here.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      FR W/C Sensor FR wheel cylinder pressure sensor / Min.: 0 V, Max.: 5 V When brake pedal is released: 0.3 to 0.7 V Reading increases when brake pedal is depressed
      FL W/C Sensor FL wheel cylinder pressure sensor / Min.: 0 V, Max.: 5 V When brake pedal is released: 0.3 to 0.7 V Reading increases when brake pedal is depressed
      RR W/C Sensor RR wheel cylinder pressure sensor / Min.: 0 V, Max.: 5 V When brake pedal is released: 0.3 to 0.7 V Reading increases when brake pedal is depressed
      RL W/C Sensor RL wheel cylinder pressure sensor / Min.: 0 V, Max.: 5 V When brake pedal is released: 0.3 to 0.7 V Reading increases when brake pedal is depressed
    4. Check that the output value of each wheel cylinder does not increase.

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

      Tech Tips

      If any output value increases, there may be a brake fluid leak in the brake actuator.


    NG
    OK