Description & Operation: Notes

The ECM is equipped with a self-diagnostic system, which detects system failures or abnormalities. When a malfunction occurs, ECM will illuminate the Malfunction Indicator Light (MIL) located on instrument cluster. When malfunction is detected and MIL is turned on, a corresponding DTC will be stored in ECM memory. To retrieve stored DTCs, see READING DTCS  or RETRIEVING DTCS (NON-SCAN). Malfunctions are recorded as HARD FAILURES or as INTERMITTENT FAILURES. When ignition is turned to ON position, MIL will come on until engine is started as a bulb check.