Self-Diagnostic Systems: Notes

Engine Control Module (ECM) is equipped with a self-diagnostic system. By analyzing various input signals, ECM detects system malfunctions related to various operating parameters. When malfunction of various engine sensors, switches or circuits occurs, a Diagnostic Trouble Code (DTC) may be stored in the ECM memory. DTC may be retrieved for system diagnosis. For additional information on self-diagnostic system, see SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.