Self-Diagnostic System

The ECU is equipped with a self-diagnostic system which detects system failures or abnormalities. When malfunction occurs, the CHECK ENGINE light on instrument panel is activated.

By analyzing various input signals, the ECU detects system malfunctions related to various operating parameters. The CHECK ENGINE light will go out when malfunction clears; however, the ECU stores trouble codes associated with the detected failure until the diagnostic system is cleared. For additional information, see TESTS W/CODES article in this section.