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Check For Intermittent Problems

  1. CHECK FOR INTERMITTENT PROBLEMS 

    HINT:

    A momentary interruption (open circuit) in the connectors and/or wire harness between the sensors and ECUs can be detected in the ECU Data List function of the Techstream.

    1. Turn the engine switch off and connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG). Follow the directions on the Techstream to display the Data List and select areas where momentary interruptions are monitored.

      HINT:

      A momentary interruption (open circuit) cannot be detected for 3 seconds after the engine switch is turned on (IG) (initial check).

      Fig 1: Monitoring Momentary Interruption
      G04949560Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      ABS/VSC/TR(A)C 

      NORMAL CONDITION CHART

      Item (Display) Measurement Item/Range (Display) Normal Condition Diagnostic Note
      FR Speed Open Front speed sensor RH open detection/ERROR or NORMAL ERROR: Momentary interruption
      NORMAL: Normal
      -
      FL Speed Open Front speed sensor LH open detection/ERROR or NORMAL ERROR: Momentary interruption
      NORMAL: Normal
      -
      RR Speed Open Rear speed sensor RH open detection/ERROR or NORMAL ERROR: Momentary interruption
      NORMAL: Normal
      -
      RL Speed Open Rear speed sensor LH open detection/ERROR or NORMAL ERROR: Momentary interruption
      NORMAL: Normal
      -
      EFI Communication Open SFI 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
      -
      Deceleration Open Deceleration 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
      -
      Master Cylinder Open Master cylinder pressure sensor open detection/ERROR or NORMAL ERROR: Momentary interruption
      NORMAL: Normal
      -
      Master Cylinder2 Open Master cylinder pressure sensor 2 open detection/ERROR or NORMAL ERROR: Momentary interruption
      NORMAL: Normal
      -
      Stroke Open Stroke sensor open detection/ERROR or NORMAL ERROR: Momentary interruption
      NORMAL: Normal
      -
      FR Wheel Cylinder Open Front wheel cylinder pressure sensor RH open detection/ERROR or NORMAL ERROR: Momentary interruption
      NORMAL: Normal
      -
      FL Wheel Cylinder Open Front wheel cylinder pressure sensor LH open detection/ERROR or NORMAL ERROR: Momentary interruption
      NORMAL: Normal
      -
      RR Wheel Cylinder Open Rear wheel cylinder pressure sensor RH open detection/ERROR or NORMAL ERROR: Momentary interruption
      NORMAL: Normal
      -
      RL Wheel Cylinder open Rear wheel cylinder pressure sensor LH open detection/ERROR or NORMAL ERROR: Momentary interruption
      NORMAL: Normal
      -
      Accumulator Open Accumulator pressure sensor open detection/ERROR or NORMAL ERROR: Momentary interruption
      NORMAL: Normal
      -

      HINT:

      • If the ERROR display remains on, check the continuity between the ECU and the sensors, or between ECUs.
      • The ERROR display remains on for 1 second after the harness signal changes from momentary interruption (open circuit) to normal condition.

      While observing the screen, gently jiggle the connector or wire harness between the ECU and sensors, or between ECUs.

      Result: ERROR display does not change. 

      HINT:

      The connector and/or wire harness will be in momentary interruption (open circuit) if the display changes. Repair or replace connector and/or wire harness as one of them is faulty.

    3. Fig 2: Checking Wire Harness
      G04832151Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002