EMISSION CONTROL SYSTEM CHECK FOR INTERMITTENT PROBLEMS


  1. CHECK FOR INTERMITTENT PROBLEMS

    As previously described, when intermittent problems occur in the emission ECU signal circuits (NE, THW, THA, PIM, VA) shown in the table, the appropriate DTC is output. Accordingly, when the DTCs shown in the table(13, 22, 31, 41) are output during the DTC check and inspection of the appropriate circuits reveals no abnormality, check intermittent problems as described below.

    By checking intermittent problems, the place where intermittent problems occur due to poor contacts can be found.

    DTC Circuit
    13 Engine speed sensor circuit
    22 Water temp. sensor circuit
    31 Vacuum sensor circuit
    41 Throttle position sensor circuit

    1. Clear the DTC

      Disconnect the battery terminals or ECU-IG fuse.

    2. Perform a simulation test

      Using the symptom simulation Click here, apply vibration to and pull lightly on the wire harness, connector or terminals in the circuit indicated by the malfunction code.

      In this test, if the glow indicator light lights up, it indicates that the place where the wire harness, connector or terminals being pulled or having vibration has faulty contact. Check points for loose connections, dirt on the terminals, poor fit or other problems and repair it as necessary.

      Tech Tips

      After cancelling out the DTC in memory if the glow indicator light does not go off after the engine is started, check thoroughly for faulty contact, etc., then try the check again. if the glow indicator light still does not go off, check and replace the emission ECU.