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Home >> Toyota >> 2009 >> Matrix XRS, Standard >> Repair and Diagnosis (Single Page) >> Brakes >> Anti-Lock Brakes >> Brake Control/Dynamic Control System >> Vehicle Stability Control System >> DTC U0073/94 Control Module Communication Bus OFF; DTC U0100/65 Lost Communication with ECM / PCM; 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 >> Inspection Procedure
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Inspection Procedure

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

      ABS/VSC/TRAC 

      ABS/VSC/TRAC DIAGNOSTIC CHART

      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 angle 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 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 

      DTC OUTPUT RESULT

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

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

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

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

  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 interruptions 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 DTCs are output (See DIAGNOSIS SYSTEM ).
    6. If ABS and VSC DTCs are output, record them (See DTC CHECK / CLEAR  ).

      Result 

      DTC OUTPUT RESULT

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

      HINT:

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

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

      C: END 

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

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