Self-Diagnostic System: Notes

The Engine Control Module (ECM) monitors the input/output signals (some signals at all times and others under specified conditions). When the ECM detects an irregularity, it memorizes the diagnostic trouble code and set Malfunction Indicator Light (MIL). Also outputs the signal to the self-diagnosis output terminal. The diagnosis results can be read by a Hi-Scan Pro or Generic Scan Tool. A Diagnostic Trouble Code (DTC) will remain in the ECM as long as battery power is maintained. The diagnostic trouble code will however be erased when the battery terminal or the ECM connector is disconnected or erased using the Hi-Scan Pro or Generic Scan Tool.