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ECU Power Source Circuit [09/2014 - 11/2017]: Procedure

  1. CHECK TERMINAL VOLTAGE (POWER SOURCE OF DRIVING SUPPORT ECU ASSEMBLY) 
    1. Disconnect the Q1 driving support ECU assembly connector.
      GTY511674Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Driving Support ECU Assembly)
    2. Measure the voltage and resistance according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      Q1-30 (B) - Body ground Engine switch on (IG) 11 to 14 V
      Q1-30 (B) - Body ground Engine switch off Below 1 V

      Standard Resistance

      Tester Connection Condition Specified Condition
      Q1-25 (GND) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [09/2014 - 11/2017] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - BATTERY AND BODY GROUND)