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Home >> Toyota >> 2021 >> 4Runner TRD Pro >> Repair and Diagnosis (Single Page) >> Restraints >> Seat Belts >> Pre-Collision System - Diagnostic Codes & Circuit Tests >> Pre-Collision System >> DTC U0100: Lost Communication with ECM / PCM "A"; DTC U0125: Lost Communication with Yaw Rate Sensor Module; DTC U0126: Lost Communication with Steering Angle Sensor Module; DTC U0129: Lost Communication with Brake System Control Module [08/2019 - ] >> Procedure
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DTC U0100: Lost Communication with ECM / PCM "A"; DTC U0125: Lost Communication with Yaw Rate Sensor Module; DTC U0126: Lost Communication with Steering Angle Sensor Module; DTC U0129: Lost Communication with Brake System Control Module [08/2019 - ]: Procedure

  1. CHECK FOR DTCs (PRE-COLLISION SYSTEM) 
    1. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [08/2019 - ]

    2. Make sure that the DTC detection conditions are met.

      HINT: 

      If the detection conditions are not met, the system cannot detect the malfunction.

    3. Check for DTCs.

      Refer to DTC CHECK / CLEAR [08/2019 - ]

      Result

      Result Proceed to
      DTC U0100, U0125, U0126 and U0129 are not output A
      DTC U0100, U0125, U0126 or U0129 is output B

    Result: 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2019 - ] 

    Result: 

    GO TO CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2019 - ]