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Home >> Lexus >> 2020 >> RC 350 Base, AWD >> Repair and Diagnosis (Single Page) >> Transmission >> Transfer Case >> Four Wheel Drive Control System - Diagnostic Codes & Circuit Tests >> Four Wheel Drive Control System >> DTC U0073/86: Control Module Communication Bus OFF; DTC U0100/85: Lost Communication with ECM / PCM "A"; DTC U0126/84: Lost Communication with Steering Angle Sensor Module; DTC U0129/83: Lost Communication with Brake System Control Module [09/2014 - 09/2020] >> Procedure
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DTC U0073/86: Control Module Communication Bus OFF; DTC U0100/85: Lost Communication with ECM / PCM "A"; DTC U0126/84: Lost Communication with Steering Angle Sensor Module; DTC U0129/83: Lost Communication with Brake System Control Module [09/2014 - 09/2020]: Procedure

  1. CHECK DTC OUTPUT 
    1. Connect the Techstream to the DLC3.
    2. Check for DTCs.

      Refer to DTC CHECK / CLEAR [09/2014 - 10/2018] , or refer to DTC CHECK / CLEAR [10/2018 - 09/2020]

      Chassis > Four Wheel Drive > Trouble Codes 

    3. Record the output DTC (4WD control system).

      HINT: 

      When DTCs indicating a CAN communication system malfunction are output, repair the CAN communication system before repairing each corresponding sensor or ECU.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING). Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2014 - 11/2017]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2017 - 10/2018]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2018 - ]