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Home >> Toyota >> 2020 >> Avalon Limited >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 113 (Electronically Controlled Brake System - Diagnostic Codes (C1202-C1300) (Hybrid)) >> ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model) >> DTC C1252: Brake Booster Pump Motor on Time Abnormally Long; DTC C1253: Pump Motor Relay [04/2018 -] >> Procedure

DTC C1252: Brake Booster Pump Motor on Time Abnormally Long; DTC C1253: Pump Motor Relay [04/2018 -]: Procedure

WARNING: This page is about a different variant/trim than selected.
  1. CHECK DTC 
    1. Check the DTCs that are output.

      Refer to DTC CHECK / CLEAR [04/2018 -]

      Chassis > ABS/VSC/TRAC > Trouble Codes 

      Result

      Result Proceed to
      DTCs C1252 and/or C1253 are output. A
      DTCs C1241 and/or C1242 are output with DTCs C1252 and/or C1253. B

    Result: 

    B 

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS. Refer to  DIAGNOSTIC TROUBLE CODE CHART [04/2018 - 08/2019]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2019 - 08/2020]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2020 - 08/2021]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2021 -] 

    Result: 

    A 

    See step  2

  2. READ VALUE USING TECHSTREAM (MOTOR RELAY 1 AND MOTOR RELAY 2) 
    1. Select the Data List on the Techstream.

      Refer to DATA LIST / ACTIVE TEST [04/2018 -]

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      ECB Motor Relay Motor relay 1 operation request ON or OFF ON: Relay on
      OFF: Relay off      		 ECB: Electronically Controlled Brake System
      ECB Motor Relay2 Motor relay 2 operation request ON or OFF ON: Relay on
      OFF: Relay off      		 ECB: Electronically Controlled Brake System

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display
      ECB Motor Relay
      ECB Motor Relay2
    2. Depress the brake pedal several times and check the operation status of the motor relay 1 and motor relay 2.

      HINT: 

      Depressing the brake pedal several times drops the accumulator pressure and operates the pump motor.

      Result

      Result Proceed to
      The motor relay 1 and motor relay 2 in the Data List turns on or off by depressing the brake pedal several times. A
      The status of motor relay 1 and motor relay 2 in the Data List does not change even after depressing the brake pedal several times. B

    Result: 

    B 

    See step  8

    Result: 

    A 

    See step  3

  3. INSPECT BRAKE BOOSTER PUMP ASSEMBLY 
    1. Turn the power switch off.
      GTY562053Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component without harness connected
      (Brake Booster Pump Assembly)
    2. Make sure that there is no looseness at the locking part and the connecting part of the connector.

      OK

      The connector is securely connected.

    3. Disconnect the A40 brake booster pump assembly connector.
    4. Check both the connector case and the terminals for deformation and corrosion.

      OK

      No deformation or corrosion.

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      2 (BM1) - 4 (GND1) Always 10 Ω or less
      1 (BM2) - 3 (GND2) Always 10 Ω or less
      2 (BM1) - 1 (BM2) Always Below 1 Ω
      4 (GND1) - 3 (GND2) Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE BRAKE BOOSTER PUMP ASSEMBLY. Refer to  REMOVAL [04/2018 - 08/2021]  , or refer to  REMOVAL [08/2021 -] 

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (GND TERMINAL) 
    1. Measure the resistance according to the value(s) in the table below.
      GTY839445Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Brake Booster Pump Assembly)

      Standard Resistance

      Tester Connection Condition Specified Condition
      A40-4 (GND1) - Body ground Always Below 1 Ω
      A40-3 (GND2) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT) 

    Result: 

    OK 

    See step  5

  5. READ VALUE USING TECHSTREAM (ACCUMULATOR PRESSURE) 
    1. Reconnect the A40 brake booster pump assembly connector.
    2. Disconnect the A34 brake pedal stroke sensor assembly connector.
    3. Select the Data List on the Techstream.

      Refer to DATA LIST / ACTIVE TEST [04/2018 -]

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      MT Voltage Value MT voltage value Min.: 0.00 V, Max.: 20.00 V Pump motor off: 0.00 V
      Pump motor on: 12.00 V      		 -
      Accumulator Pressure Accumulator pressure output value Min.: 0.00 MPa, Max.: 24.48 MPa 15.00 to 21.00 MPa
      (Pressure stable and pump motor stopped)      		 When brake fluid is stored in the accumulator: Accumulator pressure changes in accordance with volume of fluid stored in the accumulator

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display
      MT Voltage Value
      Accumulator Pressure
    4. Depress the brake pedal several times to operate the pump motor, then wait until it stops.
    5. After the pump motor stops, wait for 30 seconds, then check the drop in the accumulator pressure sensor output value and the state of the pump motor.

      HINT: 

      • This inspection checks whether an accumulator pressure sensor malfunction, internal brake actuator (brake booster with master cylinder assembly) leak or prolonged operation due to detection of low pressure caused by accumulator deterioration, caused the DTC to be stored.
      • If the brake fluid level in the brake master cylinder reservoir assembly (brake booster with master cylinder assembly) drops, an external brake fluid leak is suspected.

      Result

      Result Proceed to
      The drop in the accumulator pressure sensor output value is less than 2.50 MPa 30 seconds after the pump motor stops, and the pump motor does not operate within 30 seconds after the pump motor stops. A
      The drop in the accumulator pressure sensor output value is 2.50 MPa or more 30 seconds after the pump motor stops, or the pump motor operates within 30 seconds after the pump motor stops. B

    Result: 

    B 

    See step  7

    Result: 

    A 

    See step  6

  6. RECONFIRM DTC 
    1. Turn the power switch off.
    2. Reconnect the A34 brake pedal stroke sensor assembly connector.
    3. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [04/2018 -]

      Chassis > ABS/VSC/TRAC > Clear DTCs 

    4. Turn the power switch off.
    5. Turn the power switch on (IG).
    6. Check if the same DTC is output.

      Refer to DTC CHECK / CLEAR [04/2018 -]

      Chassis > ABS/VSC/TRAC > Trouble Codes 

      Result

      Result Proceed to
      DTCs C1252 and C1253 are not output. A
      DTCs C1252 and/or C1253 are output. B

    Result: 

    A 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [04/2018 -] 

    Result: 

    B 

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to  REMOVAL [04/2018 - 08/2021]  , or refer to  REMOVAL [08/2021 -] 

  7. READ VALUE USING TECHSTREAM (SERVO PRESSURE) 
    1. Turn the power switch off.
    2. Reconnect the A34 brake pedal stroke sensor assembly connector.
    3. Select the Active Test on the Techstream.

      Refer to DATA LIST / ACTIVE TEST [04/2018 -]

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      ECB Solenoid (SLR) Linear solenoid reduction valve (SLR) Solenoid ON/OFF ECB: Electronically Controlled Brake System

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Servo Pressure Pressure value of servo Min.: 0.00 MPa, Max.: 24.48 MPa Brake pedal released: 0.00 to 2.10 MPa Brake pedal is being depressed: Changes in proportion to the depression force of the brake pedal

      Chassis > ABS/VSC/TRAC > Active Test 

      Active Test Display
      ECB Solenoid (SLR)
      Data List Display
      Servo Pressure
    4. Perform the Active Test and operate the linear solenoid (SLR) in the brake actuator (brake booster with master cylinder assembly).
    5. Check that the servo pressure output value does not increase when performing the Active Test.

      OK

      The servo pressure output value does not increase when performing the Active Test.

      HINT: 

      If the servo pressure output value increases, an internal brake fluid leak in the brake actuator (brake booster with master cylinder assembly) is suspected.

      Result

      Result Proceed to
      The servo pressure output value increases. A
      The servo pressure output value does not increase. B

    Result: 

    A 

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to  REMOVAL [04/2018 - 08/2021]  , or refer to  REMOVAL [08/2021 -] 

    Result: 

    B 

    REPLACE BRAKE BOOSTER PUMP ASSEMBLY. Refer to  REMOVAL [04/2018 - 08/2021]  , or refer to  REMOVAL [08/2021 -] 

  8. CHECK HARNESS AND CONNECTOR (MRI TERMINAL) 
    1. Turn the power switch off.
      GTY883899Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))
    2. Make sure that there is no looseness at the locking part and the connecting part of the connector.

      OK

      The connector is securely connected.

    3. Disconnect the A35 skid control ECU (brake booster with master cylinder assembly) connector.
    4. Check both the connector case and the terminals for deformation and corrosion.

      OK

      No deformation or corrosion.

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

      Standard Voltage

      Tester Connection Condition Specified Condition
      A35-2 (MRI1) - Body ground Always 11 to 14 V
      A35-28 (MRI2) - Body ground Always 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MRI CIRCUIT) 

    Result: 

    OK 

    See step  9

  9. CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - BRAKE BOOSTER PUMP ASSEMBLY) 
    1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

      OK

      The connector is securely connected.

    2. Disconnect the A40 brake booster pump assembly connector.
    3. Check both the connector case and the terminals for deformation and corrosion.

      OK

      No deformation or corrosion.

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      A35-1 (MRO1) - A40-2 (BM1) Always Below 1 Ω
      A35-1 (MRO1) or A40-2 (BM1) - Body ground Always 10 kΩ or higher
      A35-27 (MRO2) - A40-1 (BM2) Always Below 1 Ω
      A35-27 (MRO2) or A40-1 (BM2) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to  REMOVAL [04/2018 - 08/2021]  , or refer to  REMOVAL [08/2021 -] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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