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 ABS motor relay (ABS MTR) for electronically controlled brake system control, and the ABS motor relay (ABS MTR2) for ABS control. If either is of them malfunctioning, the other will substitute.

DTC Code Information Code DTC Detection Condition Trouble Area
C1252/52 130 Motor relay is on for at least 3 minutes.

  • ABS motor relay (ABS MTR)

  • ABS motor relay (ABS MTR2)

  • Brake accumulator
C1253/53 134 When the linear solenoid power supply 1 (BS1) is 9.5 V or more, either of +BI1 or +BI2 voltage is 7 V or more, and the motor relay 1 is on, MTT input of less than 3.5 V continues for 1 second or more.

  • ABS motor relay (ABS MTR)

  • Wire harness or connector

  • Brake accumulator pump motor

  • Brake accumulator pump motor circuit
↑ 138 When the linear solenoid power supply 2 (BS2) is 9.5 V or more, either of +BI1 or +BI2 voltage is 7 V or more, and the motor relay 2 is on, MTT input of less than 3.5 V continues for 1 second or more.

  • ABS motor relay (ABS MTR2)

  • Wire harness or connector

  • Brake accumulator pump motor

  • Brake accumulator 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 motor relay (ABS MTR)

  • ABS motor relay (ABS MTR2)

  • Brake accumulator pump motor

  • Brake accumulator pump motor circuit

WIRING DIAGRAM

A001DGBE05

PROCEDURE


  1. INSPECT FUSE (ABS MTR1, ABS MTR2, ABS MAIN1 AND ABS MAIN2)


    1. Remove the ABS MTR1, ABS MTR2, ABS MAIN1 and ABS MAIN2 fuses from the engine room No. 2 relay block.

      A001EYTE01
      *1 Engine Room No. 2 Junction Block

    2. Measure the resistance of the fuses.

      Standard resistance
      Tester Connection Condition Specified Condition
      ABS MTR1 H-fuse Always Below 1 Ω
      ABS MTR2 H-fuse Always Below 1 Ω
      ABS MAIN1 Always Below 1 Ω
      ABS MAIN2 Always Below 1 Ω

    NG

    REPLACE FUSE

    OK

  2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (ABS RELAY)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Select the Active Test mode on the intelligent tester.

      Tech Tips


      • The ABS relay is a semiconductor relay. It does not emit operation sounds.

      • The ABS relay cannot be removed and inspected, as it is part of the engine room No. 2 relay block.

    4. A001ADVE05
      *1 Terminal Cover
      *2 Engine Room No. 2 Junction Block

      Remove the terminal cover.

      Skid control ECU
      Tester Display Test Part Control Range Diagnostic Note
      Electronically Controlled Brake System Motor Relay Turns electronically controlled brake system motor relay ON / OFF Operation sound of relay (clicking sound) and motor can be heard

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

      A001DG0E06
      Standard voltage
      Tester Connection Switch Condition Specified Condition
      Terminal 23 or 24 - Body ground Motor relay: ON 11 to 14 V
      Motor relay: OFF Below 1 V
      Terminal 25 or 26 - Body ground Always 11 to 14 V

    NG

    CHECK TERMINAL VOLTAGE (ENGINE ROOM NO. 2 JUNCTION BLOCK) Click here

    OK

  3. CHECK TERMINAL VOLTAGE (BM1)


    1. Disconnect the A23 pump connector.

    2. Read value of intelligent tester (ABS MTR relay).


      1. Connect the intelligent tester to the DLC3.

      2. Turn the engine switch on (IG).

      3. Select the Active Test mode on the intelligent tester.

        Skid control ECU
        Tester Display Test Part Control Range Diagnostic Note
        Electronically Controlled Brake System Motor Relay Turns electronically controlled brake system motor relay ON / OFF Operation sound of relay (clicking sound) and motor can be heard
    3. A001EHGE03
      *1 Front view of wire harness connector: (to Brake Accumulator Pump)

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      A23-2 (BM1) - Body ground ABS MTR relay: ON 11 to 14 V
      ABS MTR relay: OFF Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Select the Active Test mode on the intelligent tester.

      Skid control ECU
      Tester Display Test Part Control Range Diagnostic Note
      Electronically Controlled Brake System Motor Relay2 Turns electronically controlled brake system motor relay 2 ON / OFF Operation sound of relay (clicking sound) and motor can be heard

    4. Check the operation sound of the ABS motor relay (ABS MTR2) and motor when operating it with the intelligent tester.

      OK
      The operation sound of the ABS motor relay (ABS MTR2) and motor are heard.

    NG

    INSPECT ABS MOTOR RELAY (ABS MTR2) Click here

    OK

  5. INSPECT BRAKE ACCUMULATOR PUMP


    1. A001BQ9E03
      *1 Component without harness connected: (Brake Accumulator Pump)
      *2 MTT

      Turn the engine switch off.

    2. Disconnect the A23 and A24 pump connectors.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      A-2 (BM1) - A-4 (GND1) Always 10 Ω or less
      B-2 (BM2) - A-4 (GND1)
      A-2 (BM1) - B-2 (BM2) Always Below 1 Ω
      A-4 (GND1) - B-1 (GND2)
      A-2 (BM1) - A-1 (MTT) Always 950 to 1050 Ω
      B-2 (BM2) - A-1 (MTT)

    NG

    REPLACE BRAKE ACCUMULATOR PUMP Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE ACCUMULATOR PUMP)


    1. Turn the engine switch off.

    2. Disconnect the A19 ECU connector.

    3. Disconnect the A23 and A24 pump connectors.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      A19-37 (MTT) - A23-1 (MTT) Always Below 1 Ω
      A19-37 (MTT) - Body ground Always 10 kΩ or higher
      A23-4 (GND1) - Body ground Always Below 1 Ω
      A24-1 (GND2) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. READ VALUE USING INTELLIGENT TESTER (ACCUMULATOR SENSOR)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Select the Data List mode on the intelligent tester.

      Skid control ECU
      Tester Display

      Measurement Item /

      Range

      		 Normal Condition Diagnostic Note
      Accumulator Sensor Accumulator pressure sensor / min.: 0.00 V, max.: 5.00 V Specified value: 2.60 to 3.80 V -

    4. 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) for 30 seconds.

      OK
      The accumulator pressure sensor voltage change is within 0.2 V.

      Tech Tips


      • This inspection is performed to determine if there is a long term power malfunction when low pressure is detected in the accumulator due to a sensor malfunction, fluid leak in the actuator, or accumulator deterioration.

      • If the reservoir fluid level drops, there may be a fluid leak.


    NG

    PERFORM ACTIVE TEST USING INTELLIGENT TESTER (SMC1, SMC2, SLRRR, AND SLRRL) Click here

    OK

  8. CHECK TERMINAL VOLTAGE (ENGINE ROOM NO. 2 JUNCTION BLOCK)

    A001BY6E03
    *1 Engine Room No. 2 Junction Block (Rear Side)

    1. Disconnect the 2F junction block connector.

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

      Standard voltage
      Tester Connection Condition Specified Condition
      2F-1 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. INSPECT ENGINE ROOM NO. 2 RELAY BLOCK AND NO. 2 JUNCTION BLOCK (INNER CIRCUIT)

    A001BDHE01
    *a Engine room No. 2 Junction Block
    *b Engine room No. 2 Junction Block Terminal for Relay Inspection

    1. Turn the engine switch off.

    2. Disconnect the 2B and 2F junction block connectors.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      2F-1 - Terminal 25 or 26 Always Below 1 Ω
      2B-1 - Terminal 23 or 24 Always Below 1 Ω

    NG

    REPLACE ENGINE ROOM NO. 2 RELAY BLOCK AND NO. 2 JUNCTION BLOCK

    OK

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


    1. Turn the engine switch off.

    2. Disconnect the A19 ECU connector.

    3. Disconnect the 2G junction block connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      A19-35 (MR1) - 2G-14 Always Below 1 Ω
      A19-36 (R1-) - 2G-13 Always Below 1 Ω
      A19-35 (MR1) - Body ground Always 10 kΩ or higher
      A19-36 (R1-) - Body ground Always 10 kΩ or higher

    OK

    REPLACE ENGINE ROOM NO. 2 JUNCTION BLOCK

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  11. INSPECT ABS MOTOR RELAY (ABS MTR2)


    1. A001A7P

      Remove the ABS motor relay.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      3 - 5 When battery voltage is not applied to terminals 1 and 2 10 kΩ or higher
      3 - 5 When battery voltage is applied to terminals 1 and 2 Below 1 Ω

    NG

    REPLACE ABS MOTOR RELAY (ABS MTR2) Click here

    OK

  12. CHECK HARNESS AND CONNECTOR (NO. 3 RELAY BLOCK - BATTERY)


    1. A001DYVE01
      *1 No. 3 Relay Block
      *2 ABS Motor Relay (ABS MTR2)

      Remove the ABS motor relay (ABS MTR2).

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

      Standard voltage
      Tester Connection Condition Specified Condition
      ABS motor relay terminal 5 (ABS MTR2) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  13. CHECK HARNESS AND CONNECTOR (BRAKE ACCUMULATOR PUMP - NO. 3 RELAY BLOCK)


    1. Disconnect the A24 pump connector.

    2. Remove the ABS motor relay (ABS MTR2).

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

      Standard resistance
      Tester Connection Condition Specified Condition
      A24-2 (BM2) - ABS Motor relay terminal 3 (ABS MTR2) Always Below 1 Ω
      A24-2 (BM2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  14. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - NO. 3 RELAY BLOCK)


    1. Disconnect the A21 ECU connector.

    2. Remove the ABS motor relay (ABS MTR2).

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

      Standard resistance
      Tester Connection Condition Specified Condition
      A21-36 (MR2) - ABS motor relay terminal 1 (ABS MTR2) Always Below 1 Ω
      A21-37 (R2-) - ABS motor relay terminal 2 (ABS MTR)2 Always Below 1 Ω
      A21-37 (R2-) - Body ground Always 10 kΩ or higher
      A21-36 (MR2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  15. RECONFIRM DTC


    1. Clear the DTC Click here.

    2. Turn the engine switch on (IG).

    3. Check if the same DTCs are recorded Click here.

      Tech Tips

      Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

      Result
      Result Proceed to
      DTCs (C1252/52 and C1253/53) are not output A
      DTCs (C1252/52 and C1253/53) are output B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE SKID CONTROL ECU Click here

  16. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (SMC1, SMC2, SLRRR, AND SLRRL)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

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

      Tech Tips

      The ACTIVE TEST can be performed when the following conditions are met.


      • Main relay 1 and 2 are on.

      • Shift lever is P position.

      • Parking brake is on.

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

      Skid control ECU:
      Tester Display Test Part Control Range Diagnostic Note
      Electronically Controlled Brake System Solenoid (SCC) Turns electronically controlled brake system solenoid (SMC2) ON / OFF Operation sound of solenoid (clicking sound) can be heard
      Electronically Controlled Brake System Solenoid (SMC) Turns electronically controlled brake system solenoid (SMC1) ON / OFF Operation sound of solenoid (clicking sound) can be heard
      Electronically Controlled Brake System Solenoid (SLRRR) Valve Close Turns SLRRR solenoid ON / OFF Operation sound of solenoid (clicking sound) can be heard
      Electronically Controlled Brake System Solenoid (SLRRL) Valve Close Turns SLRRL solenoid ON / OFF Operation sound of solenoid (clicking sound) can be heard

    4. Using the intelligent tester, turn SMC1, SMC2, SLRRR, or SLRRL ON.

      A001FYQE01

    5. Check that each wheel cylinder's output value does not increase.

      OK
      Each wheel cylinder's output value does not increase.

      Tech Tips

      If any of wheel cylinder's output value increases, there may be a brake fluid leak in the brake actuator.

      Result
      Result Proceed to
      OK for LHD A
      for RHD B
      NG for LHD C
      for RHD D

    A

    REPLACE BRAKE ACCUMULATOR PUMP Click here

    B

    REPLACE BRAKE ACCUMULATOR PUMP Click here

    C

    REPLACE BRAKE ACTUATOR Click here

    D

    REPLACE BRAKE ACTUATOR Click here