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 harness between the sensors and ECUs can be detected in the ECU data monitor function of the intelligent tester.


    1. B007UCVE01

      Turn the ignition switch off and connect the intelligent tester to the DLC3.

    2. B007RWFE03

      Turn the ignition switch to the ON position. Follow the directions on the intelligent tester to display the DATA LIST and select areas where momentary interruption should be monitored.

      Tech Tips

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

      Item (Display) Measurement Item / Range (Display) Normal Condition Diagnostic Note
      FR Speed Open Speed sensor open detection (FR) / OPN DET or NORMAL

      OPN DET: Momentary interruption

      NORMAL: Normal

      		 -
      FL Speed Open Speed sensor open detection (FL) / OPN DET or NORMAL

      OPN DET: Momentary interruption

      NORMAL: Normal

      		 -
      RR Speed Open Speed sensor open detection (RR) / OPN DET or NORMAL

      OPN DET: Momentary interruption

      NORMAL: Normal

      		 -
      RL Speed Open Speed sensor open detection (RL) / OPN DET or NORMAL

      OPN DET: Momentary interruption

      NORMAL: Normal

      		 -

      Tech Tips


      • If the intelligent tester status remains on, check the continuity between the ECU and the sensors, or between ECUs.

      • The OPN DET display on the intelligent tester remains on for 1 second after the harness signal changes from momentary interruption (open circuit) to normal condition.

    3. B007RHCE02

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

      Tech Tips

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