LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2007 >> RX 400h AWD >> Repair and Diagnosis >> Brakes >> Traction Control >> Brake Control >> Electronically Controlled Brake System >> Skid Control Buzzer Circuit >> Inspection Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Inspection Procedure

NOTE: When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration (See INITIALIZATION ).
  1. PERFORM ACTIVE TEST BY INTELLIGENT TESTER (SKID CONTROL BUZZER) 
    1. Connect the intelligent tester to the DLC3.
    2. Turn the ignition switch on and turn the intelligent tester main switch on.
    3. Select ACTIVE TEST mode on the intelligent tester.

      ABS/VSC/TRAC: 

      VEHICLE CONDITION DIAGNOSTIC CHART

      Item (Display) Vehicle Condition/Test Details Diagnostic Note
      BUZZER Turns skid control buzzer ON/OFF Buzzer can be heard
    4. Check that the buzzer sounds/stops when turning the skid control buzzer on/off using the intelligent tester.

    Result 

    RESULT CHART

    Condition Proceed To
    Buzzer sounds/stops A
    Buzzer does not sound or sounds constantly B

    HINT:

    If troubleshooting has been carried out according to the PROBLEM SYMPTOMS TABLE, refer back to the table and proceed to the next step (See PROBLEM SYMPTOMS TABLE ).

    A: END 

    B: Go to next step 

  2. INSPECT SKID CONTROL BUZZER (POWER SOURCE TERMINAL) 
    1. Disconnect the skid control buzzer connector.
    2. Turn the ignition switch on.
    3. Measure the voltage according to the value(s) in the table below.

    Voltage 

    TESTER CONNECTION SPECIFIED CONDITION CHART

    Tester Connection Condition Specified Condition
    V8-2 - Body ground Ignition switch on 10 to 14 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 1: Inspecting Skid Control Buzzer Connector Terminal (Power Source Terminal)
    G05202773Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

    OK: Go to next step 

  3. INSPECT SKID CONTROL BUZZER 
    1. Disconnect the skid control buzzer connector.
    2. Apply battery negative voltage to terminal 1, and battery positive voltage to terminal 2 of the skid control buzzer, and then check that the buzzer sounds.

      OK: Skid control buzzer sounds. 

    NG: REPLACE SKID CONTROL BUZZER 

    Fig 2: Inspecting Skid Control Buzzer Connector Terminal
    G05202774Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

    OK: Go to next step 

  4. CHECK HARNESS AND CONNECTOR (BETWEEN SKID CONTROL ECU AND SKID CONTROL BUZZER) 
    1. Disconnect the skid control buzzer connector and the skid control ECU connector.
    2. Measure the resistance according to the value(s) in the table below.

      Resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      S39-33 (VBZ) - V8-2 (VBZ) Below 1 Ω
      S39-12 (BZ) - V8-1 (BZ) Below 1 Ω
    3. Measure the resistance according to the value(s) in the table below.

    Resistance 

    TESTER CONNECTION SPECIFIED CONDITION CHART

    Tester Connection Specified Condition
    S39-33 (VBZ) - Body ground 10 kΩ or higher
    S39-12 (BZ) - Body ground 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 3: Identifying Skid Control Buzzer Connector And Skid Control ECU Connector
    G05276933Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

    OK: Go to next step 

  5. INSPECT SKID CONTROL ECU (GND TERMINAL) 
    1. Measure the resistance according to the value(s) in the table below.

    Resistance 

    TESTER CONNECTION SPECIFIED CONDITION CHART

    Tester Connection Specified Condition
    S38-1 (GND1) - Body ground Below 1 Ω
    S39-2 (GND2) - Body ground Below 1 Ω
    S39-1 (GND3) - Body ground Below 1 Ω
    S40-2 (GND4) - Body ground Below 1 Ω
    S40-1 (GND5) - Body ground Below 1 Ω
    S41-4 (GND6) - Body ground Below 1 Ω
    Fig 4: Identifying Skid Control ECU Connector Terminal (GND Terminal)
    G05276879Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE SKID CONTROL ECU