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