ELECTRONICALLY CONTROLLED BRAKE SYSTEM CHECK FOR INTERMITTENT PROBLEMS


  1. CHECK FOR INTERMITTENT PROBLEMS

    Tech Tips

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


    1. Turn the power switch off.

    2. Connect the GTS to the DLC3.

    3. Turn the power switch on (IG).

    4. Turn the GTS on.

    5. Follow the directions on the GTS to display the Data List and select areas where momentary interruptions should be monitored.

      Tech Tips


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

      • If Error remains displayed for one of the items on the GTS, check for continuity between the ECU and the item for which Error is displayed.

      • If a momentary interruption occurs and Error is displayed on the GTS, Error will remain displayed on the GTS for 1 second after the circuit returns to normal.


      Chassis > ABS/VSC/TRC > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      FR Speed Open Front speed sensor RH open detection Error or Normal Normal: Normal Error: Momentary interruption
      FL Speed Open Front speed sensor LH open detection Error or Normal Normal: Normal Error: Momentary interruption
      RR Speed Open Rear speed sensor RH open detection Error or Normal Normal: Normal Error: Momentary interruption
      RL Speed Open Rear speed sensor LH open detection Error or Normal Normal: Normal Error: Momentary interruption
      Yaw Rate Open Yaw rate sensor open detection Error or Normal Normal: Normal Error: Momentary interruption
      Deceleration Open Acceleration sensor open detection Error or Normal Normal: Normal Error: Momentary interruption
      Steering Open Steering angle sensor open detection Error or Normal Normal: Normal Error: Momentary interruption
      Master Cylinder Open Regulator pressure sensor open detection Error or Normal Normal: Normal Error: Momentary interruption
      Stroke Open Brake pedal stroke sensor assembly open detection Error or Normal Normal: Normal Error: Momentary interruption
      FR Wheel Cylinder Open Wheel cylinder pressure sensor open detection Error or Normal Normal: Normal Error: Momentary interruption
      Accumulator Open Accumulator pressure sensor open detection Error or Normal Normal: Normal Error: Momentary interruption
      HV Communication Open Hybrid vehicle communication open detection Error or Normal Normal: Normal Error: Momentary interruption

    6. While observing the screen, gently jiggle the connectors or wire harnesses between the ECUs and sensors, or between ECUs.

      Tech Tips

      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.