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.

  • ABS MTR1 relay

  • ABS MTR1 relay circuit

  • ABS MTR2 relay

  • ABS 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 (ABS NO. 1 fuse)

  • ABS MTR1 relay

  • ABS 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 (ABS NO. 2 fuse)

  • ABS MTR2 relay

  • ABS 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.

  • ABS MTR1 relay circuit

  • ABS MTR2 relay circuit

  • Brake booster pump (Pump motor)

  • Pump motor circuit

WIRING DIAGRAM

A01NI5ME02

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

    INSPECT ABS NO. 1, 2 FUSE Click here

    OK

  2. INSPECT BRAKE BOOSTER PUMP


    1. A01NMJ7E08
      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

    REPLACE BRAKE BOOSTER PUMP Click here

    OK

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


    1. A01NMNAE03
      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

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    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

    PERFORM ACTIVE TEST USING INTELLIGENT TESTER (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 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

    REPLACE SKID CONTROL ECU Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

  6. INSPECT ABS NO. 1, 2 FUSE


    1. A01NKA4E05
      Text in Illustration
      *1 Engine Room Relay Block and Junction Block Assembly
      *2 ABS NO. 1 Fuse
      *3 ABS NO. 2 Fuse

      Turn the power switch off.

    2. Remove the fusible link block from the engine room relay block and junction block assembly.

    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
      ABS NO. 1 (50 A) fuse - Body ground Always Below 1 Ω
      ABS NO. 2 (50 A) fuse - Body ground Always Below 1 Ω

    NG

    REPLACE FUSIBLE LINK BLOCK (ABS NO. 1, 2 FUSE)

    OK

  7. INSPECT ABS MOTOR RELAY (ABS MTR1, 2)


    1. A01NIVIE11
      Text in Illustration
      *1 ABS Motor Relay (ABS MTR1, 2 Relay)

      Install the fusible link block to the engine room relay block and junction block assembly.

    2. Remove the ABS MTR1 relay and the ABS 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

    NG

    REPLACE ABS MOTOR RELAY (ABS MTR1, 2)

    OK

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


    1. A01NI5YE01
      Text in Illustration
      *1 Engine Room No. 2 Relay Block
      *2 ABS MTR1 Relay
      *3 ABS MTR2 Relay

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

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

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


    1. A01NLZ6E02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Brake Booster Pump)
      *2 Engine Room No. 2 Relay Block
      *3 ABS MTR1 Relay
      *4 ABS 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) - ABS MTR1 relay terminal 3 Always Below 1 Ω
      A83-2 (BM1) - Body ground Always 10 kΩ or higher
      A84-2 (BM2) - ABS MTR2 relay terminal 3 Always Below 1 Ω
      A84-2 (BM2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A01NITLE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)
      *2 Engine Room No. 2 Relay Block
      *3 ABS MTR1 Relay
      *4 ABS 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) - ABS MTR1 relay terminal 2 Always Below 1 Ω
      A89-11 (MR1) - Body ground Always 10 kΩ or higher
      A89-24 (R1-) - ABS MTR1 relay terminal 1 Always Below 1 Ω
      A89-24 (R1-) - Body ground Always 10 kΩ or higher
      A92-14 (R2-) - ABS MTR2 relay terminal 1 Always Below 1 Ω
      A92-14 (R2-) - Body ground Always 10 kΩ or higher
      A92-17 (MR2) - ABS MTR2 relay terminal 2 Always Below 1 Ω
      A92-17 (MR2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE SKID CONTROL ECU Click here

  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.

      A01NLS6E02

    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

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    OK

    REPLACE BRAKE BOOSTER PUMP Click here