ANTI-LOCK 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 ECU Data List function of the intelligent tester.


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the intelligent tester on.

    5. A005GREE47
      Text in Illustration
      *a Harness Signal
      *b Tester Display
      *c OK
      *d Momentary interruption
      *e ERROR
      *f NORMAL
      *g 1 Second

      Follow the directions on the intelligent tester 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 ignition switch is turned to ON (initial check).

      • If the Error display remains displayed, measure the resistance between the ECUs and sensors, or between ECUs.

      • The Error display on the intelligent tester will remain displayed for 1 second after the harness signal changes from momentary interruption (open circuit) to the normal condition.

      ABS/VSC/TRC
      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

      		 -
    6. A005J68E08
      Text in Illustration
      *a Shake Slightly
      *b Vibrate Slightly

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

      Tech Tips

      If the display changes, the connector and/or the wire harness has caused a momentary interruption of the circuit. Repair or replace the connector and/or wire harness as one of them is faulty.