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Home >> Lexus >> 2008 >> RX 400h AWD >> Repair and Diagnosis >> Brakes >> Traction Control >> Brake Control >> Electronically Controlled Brake System >> DTC U0073/94 Control Module Communication Bus OFF; DTC U0123/62 Lost Communication with Yaw Rate Sensor Module; DTC U0124/95 Lost Communication with Lateral Acceleration Sensor Module; DTC U0126/63 Lost Communication with Steering Angle Sensor Module; DTC U0293/59 Communication Error from HV ECU >> 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 a DTC (See CHECK FOR INTERMITTENT PROBLEMS  ).

      ABS / VSC / TRAC: 

      MEASUREMENT ITEM/RANGE REFERENCE

      Tester Display Measurement Item/Range Normal Condition
      HV Communication Open HV communication open detection / ERROR or NORMAL ERROR: Momentary interruption
      NORMAL: Normal
      Steering Open Steering angle sensor 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

      OK: There are no momentary interruptions. 

      HINT:

      Perform the above inspection before removing the sensor and connector.

    NG: Go to step  3

    OK: Go to next step 

  2. RECONFIRM DTC 
    1. Record the output DTCs (for ABS, VSC, Electronically Controlled Brake and CAN communication) (See DTC CHECK / CLEAR  ).

      HINT:

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

      Result 

      RESULT CHART

      Condition Proceed To
      DTC is not output A
      DTC is output B

    B: REPAIR CIRCUIT INDICATED BY OUTPUT CODE 

    A: REPAIR CAN COMMUNICATION SYSTEM 

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

      Result 

      RESULT CHART

      Condition Proceed To
      DTC for the CAN communication system is output A
      No DTC is output (ABS, VSC and Electronically Controlled Brake DTCs are output) B
      No DTC is output (No ABS, VSC and Electronically Controlled Brake DTCs are output) C

      HINT:

      The CAN communication system must be normal when repairing the sensor DTCs (for ABS, VSC and Electronically Controlled Brake).

    B: REPAIR CIRCUIT INDICATED BY OUTPUT CODE 

    C: END 

    A: REPAIR CAN COMMUNICATION SYSTEM