LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2021 >> NX 300 Base, AWD >> Repair and Diagnosis (Single Page) >> Brakes >> Traction Control >> Vehicle Stability Control System- Diagnostic Codes (3 Of 3) & Circuit Tests >> Vehicle Stability Control System >> DTC U0073: Control Module Communication Bus OFF; DTC U0100: Lost Communication with ECM; DTC U0124: Lost Communication with Lateral Acceleration Sensor Module; DTC U0126: Lost Communication with Steering Angle Sensor Module; DTC U0128: Lost Communication With EPB Module [10/2014 - 05/2019] >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC U0073: Control Module Communication Bus OFF; DTC U0100: Lost Communication with ECM; DTC U0124: Lost Communication with Lateral Acceleration Sensor Module; DTC U0126: Lost Communication with Steering Angle Sensor Module; DTC U0128: Lost Communication With EPB Module [10/2014 - 05/2019]: Procedure

  1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION) 
    1. Using the Techstream, check for any momentary interruption in the wire harness and connector corresponding to a DTC.

      Refer to CHECK FOR INTERMITTENT PROBLEMS [10/2014 - 05/2019]

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      EFI Communication Open ECM communication open detection Normal or Error Normal Error: Momentary interruption
      Yaw Rate Open Yaw rate sensor open detection Normal or Error Normal Error: Momentary interruption
      Deceleration Open Acceleration sensor open detection Error or Normal Normal Error: Momentary interruption
      Steering Open Steering sensor open detection Normal or Error Normal Error: Momentary interruption

      Chassis > ABS/VSC/TRAC > Data List 

      Tester Display
      EFI Communication Open
      Yaw Rate Open
      Deceleration Open
      Steering Open

      HINT: 

      Perform the above inspection before removing the sensor and connector.

      Result

      Proceed to
      There is a constant open circuit
      There are no momentary interruptions
      There are momentary interruptions

    Result: 

    There are no momentary interruptions 

    See step  3

    Result: 

    There are momentary interruptions 

    See step  4

    Result: 

    There is a constant open circuit 

    See step  2

  2. CHECK IF EACH SENSOR AND ECM CONNECTOR IS SECURELY CONNECTED 
    1. Turn the engine switch off.
    2. Check if each sensor or ECM connector is securely connected.

      OK

      Each connector is securely connected.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    CONNECT CONNECTOR TO EACH SENSOR OR ECM CORRECTLY 

    Result: 

    OK 

    See step  3

  3. RECONFIRM DTC 
    1. Turn the engine switch off.
    2. Record the output DTCs (for VSC system and/or CAN communication system).

      for VSC system: Refer to DTC CHECK / CLEAR [10/2014 - 05/2019]

      for CAN communication system: Refer to DIAGNOSIS SYSTEM [10/2014 - 09/2017] , or refer to DIAGNOSIS SYSTEM [09/2017 - 05/2018] , or refer to DIAGNOSIS SYSTEM [05/2018 - 05/2019]

      Chassis > ABS/VSC/TRAC > Trouble Codes 

      HINT: 

      If the CAN communication system DTC and the relevant sensor DTCs are output simultaneously, troubleshoot the relevant sensor DTCs (for VSC system) after the CAN communication system returns to normal.

      Result

      Result Proceed to
      DTC (relating to CAN communication system) is output A
      DTC (relating to VSC system) is output B
      DTC is not output C

    Result: 

    A 

    CHECK CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2014 - 09/2017]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2017 - 05/2019] 

    Result: 

    B 

    REPAIR CIRCUIT INDICATED BY OUTPUT DTC. Refer to  DIAGNOSTIC TROUBLE CODE CHART [10/2014 - 09/2017]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [09/2017 - 05/2019] 

    Result: 

    C 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2014 - 09/2017]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2017 - 05/2019] 

  4. REPAIR OR REPLACE HARNESS OR CONNECTOR 
    1. Turn the engine switch off.
    2. Repair or replace the harness or connector.
    3. Check for any momentary interruption between the skid control ECU (brake actuator assembly) and each sensor or ECM.

      Refer to CHECK FOR INTERMITTENT PROBLEMS [10/2014 - 05/2019]

    4. Check that there is no momentary interruption.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  5

  5. RECONFIRM DTC 
    1. Turn the engine switch off.
    2. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [10/2014 - 05/2019]

      Chassis > ABS/VSC/TRAC > Clear DTCs 

    3. Start the engine.
    4. Drive the vehicle at a speed of 15 km/h (9 mph) or more and turn the steering wheel to the right and left.
    5. Check that no CAN communication system DTC is output.

      Refer to DIAGNOSIS SYSTEM [10/2014 - 09/2017] , or refer to DIAGNOSIS SYSTEM [09/2017 - 05/2018] , or refer to DIAGNOSIS SYSTEM [05/2018 - 05/2019]

    6. If VSC system DTCs are output, record them.

      Refer to DTC CHECK / CLEAR [10/2014 - 05/2019]

      Chassis > ABS/VSC/TRAC > Trouble Codes 

      HINT: 

      The CAN communication system must be normal when repairing each sensor DTC (for VSC system).

      Result

      Result Proceed to
      DTC is not output A
      DTC is output (relating to VSC system) B
      DTC is output (relating to CAN communication system) C

    Result: 

    A 

    END 

    Result: 

    B 

    REPAIR CIRCUIT INDICATED BY OUTPUT DTC. Refer to  DIAGNOSTIC TROUBLE CODE CHART [10/2014 - 09/2017]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [09/2017 - 05/2019] 

    Result: 

    C 

    CHECK CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2014 - 09/2017]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2017 - 05/2019] 

scientia non olet · About LEMON Manuals