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Inspection Procedure

NOTE: When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration (see INITIALIZATION  ).

HINT:

DTCs may be output if the accumulator pressure drops due to frequent braking (this is not a malfunction).

  1. INSPECT BRAKE ACTUATOR ASSEMBLY 
    1. Disconnect the brake actuator connector.
    2. Measure the resistance of the actuator.

      Standard resistance 

      STANDARD RESISTANCE REFERENCE CHART

      Tester Connection Specified Condition
      A2-1 (BM2) - A2-31 (GND1) Below 10 Ω
      A2-2(BM1) - A2-31 (GND1) Below 10 Ω
      A2-1 (BM2) - A2-2(BM1) Below 1 Ω
      A2-31 (GND1) - A2-32 (GND2) Below 1 Ω
      A2-1 (BM2) - A2-33 (MTT) Approx. 10 Ω
      A2-2(BM1) - A2-33(MTT) Approx. 10 Ω

    NG: REPLACE BRAKE ACTUATOR ASSEMBLY 

    Fig 1: Inspecting Brake Actuator Assembly
    G05189268Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  2. READ VALUE OF TECHSTREAM (ACCUMULATOR PRESSURE SENSOR) 
    1. Check the DATA LIST for proper functioning of the accumulator pressure sensor.
    2. Depress the brake pedal 4 or 5 times to operate the pump motor, and check the output value on the Techstream with the motor stopped (not braking).

      ABS / VSC / TRAC: 

      SKID CONTROL ECU DIAGNOSTIC CHART

      Tester Display Measurement Item / Range Normal condition Diagnostic Note
      ACC PRESS SENS 1 Accumulator pressure sensor 1 / Min.: 0V, Max.: 5V Specified value: 3.2 to 4.0 V -

      OK: Accumulator pressure sensor's output voltage does not drop. 

    NG: REPLACE BRAKE ACTUATOR ASSEMBLY 

    OK: REPLACE SKID CONTROL ECU 

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