FixVault

Check For Intermittent Problems

  1. CHECK FOR INTERMITTENT PROBLEMS 

    HINT:

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

    1. Turn the power switch off.
    2. Connect the Techstream to the DLC3.
    3. Turn the power switch on (IG).
    4. Turn the Techstream on.
    5. Follow the directions on the Techstream to display the Data List and select areas where momentary interruptions should be monitored.

      HINT:

      • A momentary interruption (open circuit) cannot be detected for 3 seconds after the power switch is turned on (IG) (initial check).
      • If the ERROR display remains displayed, check for continuity between the ECUs and the sensors, or between ECUs.
      • The ERROR display on the Techstream will remain displayed for 1 second after the harness signal changes from momentary interruption (open circuit) to normal condition.
      Fig 1: Momentary Interruption - Blinking Pattern
      G05641870Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      ABS / VSC / TRAC: 

      DATA LIST AND ACTIVE TEST - ABS / VSC / TRAC

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      FR Speed Open FR speed sensor open detection / ERROR or NORMAL ERROR: Momentary interruption NORMAL: Normal -
      FL Speed Open FL speed sensor open detection / ERROR or NORMAL ERROR: Momentary interruption NORMAL: Normal -
      RR Speed Open RR speed sensor open detection / ERROR or NORMAL ERROR: Momentary interruption NORMAL: Normal -
      RL Speed Open RL speed 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 -
      Deceleration Open Acceleration 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 Cylinder 2 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 FR wheel cylinder pressure sensor open detection / ERROR or NORMAL ERROR: Momentary interruption NORMAL: Normal -
      FL Wheel Cylinder Open FL wheel cylinder pressure sensor open detection / ERROR or NORMAL ERROR: Momentary interruption NORMAL: Normal -
      RR Wheel Cylinder Open RR wheel cylinder pressure sensor open detection / ERROR or NORMAL ERROR: Momentary interruption NORMAL: Normal -
      RL Wheel Cylinder Open RL wheel cylinder pressure sensor 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 -
      HV Communication Open Hybrid vehicle communication open detection / ERROR or NORMAL ERROR: Momentary interruption NORMAL: Normal -
    6. While observing the screen, gently jiggle the connectors or wire harnesses between the ECUs and sensors, or between ECUs.

      OK: NORMAL display appears. 

      HINT:

      If the display changes, this indicates that there has been a momentary interruption (open circuit) in the connector and/or wire harness. In this case, repair or replace the connectors and/or wire harnesses as one of them is faulty.

      Fig 2: Jiggling Connector Or Wire Harness Between ECU And Sensors
      G04832151Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002