Check For Intermittent Problems

System Overview
Detection ability in test mode is increased compared to that in the normal mode, so that when momentary interruptions or momentary shorts occur in the ECM signal circuits (G1, G2, NE, THW, THA, VTA1, VTA2) shown in the table below, the appropriate diagnostic code is output.

Accordingly, when the diagnostic codes are output during the diagnostic code check, and inspection of the appropriate circuits reveals no abnormality, perform the check for momentary interruption as described below.


Inspection

- Clear diagnostic codes.
- Set test mode.
- 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 Malfunction Indicator light lights up, it indicates that the place where the wire harness, connector or terminals being pulled or vibrated has faulty contact. Check that point for loose connections, dirt on the terminals, poor fit or other problems and repair as necessary.

HINT: After cancelling out the diagnostic code in memory and set the test mode, if the Malfunction Indicator light does not go off after the engine is started, check thoroughly for faulty contact, etc., then try the check again. If the Malfunction Indicator light still does not go off, check and replace ECM.