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Home › Toyota › 2009 › Highlander Limited, AWD › Repair and Diagnosis › Brakes › Traction Control › Brake Control - Except Hybrid › Vehicle Stability Control System › DTC U0073 Control Module Communication Bus OFF; DTC U0100 Lost Communication with ECM/PCM; DTC U0123 Lost Communication with Yaw Rate Sensor Module; DTC U0124 Lost Communication with Lateral Acceleration Sensor Module; DTC U0126 Lost Communication with Steering Angle Sensor Module › Inspection Procedure

Inspection Procedure

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

    ABS/VSC/TRAC: 

    ABS/VSC/TRAC TESTER DISPLAY REFERENCE

    Tester Display Measurement Item/Range Normal Condition Diagnostic Note
    EFI Communication Open EFI communication open detection/ERROR or NORMAL ERROR: Momentary interruption NORMAL: Normal -
    Yaw Rate Open Yaw rate sensor open detection/ERROR or NORMAL ERROR: Momentary interruption NORMAL: Normal -
    Steering Open Steering sensor open detection/ERROR or NORMAL ERROR: Momentary interruption NORMAL: Normal -

    Result 

    RESULT CHART

    Result Proceed to
    There is a constant open circuit A
    There are no momentary interruptions B
    There are momentary interruptions C

    HINT:

    Perform the above inspection before removing the sensor and connector.

    B: Go to step  3

    C: Go to step  4

    A: Go to next step 

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

    OK: 

    Each connector is securely connected. 

    NG: CONNECT CONNECTOR TO EACH SENSOR OR ECM CORRECTLY 

    OK: Go to next step 

  3. RECONFIRM DTC 
    1. Turn the ignition switch off.
    2. Record the output DTCs (for ABS, VSC system and/or CAN communication system) (See DTC CHECK/CLEAR  for ABS and VSC system, or See DIAGNOSIS SYSTEM for CAN communication system).

    HINT:

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

    Result 

    RESULT CHART

    Result Proceed to
    DTC is not output A
    DTC (ABS and/or VSC system DTC) is output B
    DTC (CAN communication system DTC) is output C

    B: REPAIR CIRCUIT INDICATED BY OUTPUT DTC  (See DIAGNOSTIC TROUBLE CODE CHART )

    C: INSPECT CAN COMMUNICATION SYSTEM  (See HOW TO PROCEED WITH TROUBLESHOOTING )

    A: CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)  (See DIAGNOSIS SYSTEM )

  4. REPAIR OR REPLACE HARNESS OR CONNECTOR 
    1. Turn the ignition switch off.
    2. Repair or replace the harness or connector.
    3. Check for any momentary interruption between the skid control ECU and each sensor or ECM (See CHECK FOR INTERMITTENT PROBLEMS ).
    4. Check that there are no momentary interruptions.
  5. RECONFIRM DTC 
    1. Turn the ignition switch off.
    2. Clear the DTCs (See DTC CHECK/CLEAR ).
    3. Start the engine.
    4. Drive the vehicle and turn the steering wheel to the right and left at a speed of 15 km/h (9 mph) or more.
    5. Check that no CAN communication system DTC is output (See DIAGNOSIS SYSTEM ).
    6. If ABS and/or VSC system DTCs are output, record them.

    Result 

    RESULT CHART

    Result Proceed to
    DTC is not output A
    DTC (ABS and/or VSC system DTC) is output B
    DTC (CAN communication system DTC) is output C

    HINT:

    The CAN communication system must be normal when performing troubleshooting for each sensor DTC (for ABS and/or VSC system).

    B: REPAIR CIRCUIT INDICATED BY OUTPUT DTC  (See DIAGNOSTIC TROUBLE CODE CHART )

    C: INSPECT CAN COMMUNICATION SYSTEM  (See HOW TO PROCEED WITH TROUBLESHOOTING )

    A: END 

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