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ECU Power Source Circuit [08/2019 - 08/2021]: Procedure

  1. CHECK MILLIMETER WAVE RADAR SENSOR ASSEMBLY (B VOLTAGE) 
    1. Disconnect the k1 millimeter wave radar sensor assembly connector.
      GTY859789Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Millimeter Wave Radar Sensor Assembly)
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      k1-8 (IGB) - Body ground Ignition switch ON 11 to 14 V
    4. Turn the ignition switch off.
    5. Connect the k1 millimeter wave radar sensor assembly connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  4

    Result: 

    OK 

    See step  2

  2. CHECK HARNESS AND CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - BODY GROUND) 
    1. Disconnect the k1 millimeter wave radar sensor assembly connector.
      GTY859788Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Millimeter Wave Radar Sensor Assembly)
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      k1-1 (SGND) - Body ground Always Below 1 Ω
    3. Connect the k1 millimeter wave radar sensor assembly connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [08/2019 - ] 

    Result: 

    NG 

    See step  3

  3. CHECK MILLIMETER WAVE RADAR WIRE 
    1. Disconnect the k1 millimeter wave radar sensor assembly connector.
    2. Disconnect the Ak1 millimeter wave radar wire connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      k1-1 (SGND) - Ak1-1 Always Below 1 Ω
    4. Connect the k1 millimeter wave radar sensor assembly connector.
    5. Connect the Ak1 millimeter wave radar wire connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    NG 

    REPAIR MILLIMETER WAVE RADAR WIRE. Refer to  REMOVAL [08/2019 - 08/2021] 

  4. CHECK MILLIMETER WAVE RADAR WIRE 
    1. Disconnect the k1 millimeter wave radar sensor assembly connector.
    2. Disconnect the Ak1 millimeter wave radar wire connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      k1-8 (IGB) - Ak1-8 Always Below 1 Ω
      Ak1-8 - Ak1-1 Always 10 kΩ or higher
    4. Connect the k1 millimeter wave radar assembly connector.
    5. Connect the Ak1 millimeter wave radar sensor wire connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) 

    Result: 

    NG 

    REPAIR MILLIMETER WAVE RADAR WIRE. Refer to  REMOVAL [08/2019 - 08/2021]