On Board Diagnostic System Function

On Board Diagnostic System Function

The on board diagnostic system has the following 3 functions.






When there is an open circuit on MIL circuit, the ECM cannot warn the driver by illuminating MIL when there is malfunction on engine control system.

Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected as NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by means of operating fail-safe function.

The fail-safe function also operates when above diagnoses except MIL circuit are detected, and demands the driver to repair the malfunction.






MIL Flashing Without DTC
When any SRT codes are not set, MIL may flash without DTC. For the details, refer to [DTC Index: ECM]. Diagnostic Trouble Code Descriptions