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Inspection Procedure

NOTE: When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration (see INITIALIZATION  ).
  1. CHECK BRAKE CONTROL POWER SUPPLY (IG VOLTAGE) 
    1. Measure the voltage of the connector.

      HINT:

      Measure the voltage from behind the connector with the connector connected to the skid control ECU.

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Condition Specified Condition
      B18-5 (IG) - Body ground Power switch ON (READY) 10 to 14 V

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    Fig 1: Checking Brake Control Power Supply (IG Voltage)
    G05189309Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  2. CHECK WIRE HARNESS (SKID CONTROL ECU - BRAKE CONTROL POWER SUPPLY) 
    1. Disconnect the S8 ECU connector.
    2. Disconnect the B18 supply connector.
    3. Measure the resistance of the wire harness side connectors.

      Standard resistance 

      STANDARD RESISTANCE REFERENCE CHART

      Tester Connection Specified Condition
      S8-30 (ENA) - B18-12 (ENA) Below 1 Ω
      S8-20 (FAIL) - B18-13 (FAIL) Below 1 Ω
      S8-30 (ENA) - Body ground 10 kΩ or higher
      S8-20 (FAIL) - Body ground 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    Fig 2: Disconnecting S8 ECU And B18 Supply Connector
    G05189310Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  3. CHECK SKID CONTROL ECU (ENA, FAIL VOLTAGE) 
    1. Using an oscilloscope, check the waveform of the skid control ECU.

      OK: 

      Waveform is output as shown in the illustration. 

      Waveform (FAIL) 

      WAVEFORM REFERENCE CHART

      Item Content
      Symbols (terminal No.) S8-20 (FAIL) - S8-1, 2 (GND3, 2)
      Tool Setting 5 V/DIV/., 200 ms/DIV.
      Condition Condition READY is displayed on the meter

      Waveform (ENA) 

      WAVEFORM REFERENCE CHART

      Item Content
      Symbols (terminal No.) S8-30 (ENA) - S8-1, 2 (GND3, 2)
      Tool Setting 5 V/DIV/., 100 ms/DIV.
      Condition Condition READY is displayed on the meter
      Fig 3: Checking Waveform Of Skid Control ECU
      G05189311Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Result 

      DTC RESULT REFERENCE

      Result Proceed to
      A Both waveforms are normal
      B Waveform (ENA) is abnormal
      C Waveform (FAIL) is abnormal

    B: REPLACE BRAKE CONTROL POWER SUPPLY 

    C: REPLACE SKID CONTROL ECU 

    A: REPLACE SKID CONTROL ECU