DESCRIPTION
PCM is equipped with On Board Diagnostics-II (OBD-II) self-diagnostic system, which detects system failures or abnormalities affecting vehicle emissions. When malfunction occurs, Malfunction Indicator Light (MIL) on instrument cluster is turned on.
By analyzing various input signals, PCM detects system malfunctions in emission-related systems. PCM stores diagnostic trouble codes associated with the detected failure until the diagnostic system is cleared. For further information, see appropriate SELF-DIAGNOSTICS article.