ELECTRONICALLY CONTROLLED BRAKE SYSTEM > CHECK FOR INTERMITTENT PROBLEMS

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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 intelligent tester.

  1. Turn the power switch off.

  2. Connect the intelligent tester to the DLC3.

  3. Turn the power switch on (IG).

  4. Turn the intelligent tester on.

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

    HINT:
    1. A momentary interruption (open circuit) cannot be detected for 3 seconds after the power switch is turned on (IG) (initial check).
    2. If the Error display remains displayed, check for continuity between the ECUs and the sensors, or between ECUs.
    3. The Error display on the intelligent tester will remain displayed for 1 second after the harness signal changes from momentary interruption (open circuit) to normal condition.


    ABS/VSC/TRC 
    Tester Display
    		Measurement Item/Range
    		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
    		-
    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
    		Regulator pressure sensor open detection / Error or Normal
    		Error: Momentary interruption
    Normal: Normal
    		-
    Stroke Open
    		Brake pedal stroke sensor open detection / Error or Normal
    		Error: Momentary interruption
    Normal: Normal
    		-
    FR Wheel Cylinder Open
    		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.