FixVault

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 monitor function of Techstream.

    1. Turn the ignition switch off and connect Techstream to the DLC3.
    2. Turn the ignition switch to ON. Follow the on-screen directions on Techstream to display the Data List and select areas where momentary interruption should be monitored.
      Fig 1: Blinking Pattern Of Ignition Switch
      G05556453Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      ABS/VSC/TRAC 

      DATA LIST REFERENCE

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      FR Speed Open Front speed sensor RH open detection/OPN DET or NORMAL OPN DET: Momentary interruption
      NORMAL: Normal
      -
      FL Speed Open Front speed sensor LH open detection/OPN DET or NORMAL OPN DET: Momentary interruption
      NORMAL: Normal
      -
      RR Speed Open Rear speed sensor RH open detection/OPN DET or NORMAL OPN DET: Momentary interruption
      NORMAL: Normal
      -
      RL Speed Open Rear speed sensor LH open detection/OPN DET or NORMAL OPN DET: Momentary interruption
      NORMAL: Normal
      -

      HINT:

      • A momentary interruption (open circuit) cannot be detected for 3 seconds after the ignition switch is turned to ON (initial check).
      • If OPN DET is displayed on Techstream, check the wire harness and connectors between the ECU and sensors.
      • The OPN DET display on Techstream remains on for 1 second after the harness signal changes from momentary interruption (open circuit) to normal condition.
    3. While observing the combination meter display, gently jiggle the connector or wire harness between the ECU and sensors, or between ECUs.

      Result: 

      OPN DET display does not change. 

      HINT:

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

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