Outline Of Diagnosis
This monitor intrusively performs a functional check to detect incorrect purge flow. The monitor seals the EVAP system (i.e. isolate from atmosphere) by closing the Evaporative Leak Check Module switching valve intrusively after recovering from a fuel cut event. In the case of normal condition, and the commanded purge control duty ratio is more than 0%, Evaporative Leak Check Module pressure (gauge) will decrease due to engine vacuum and reach to the threshold value. However, in the case of malfunction condition (e.g. fuel cap open, purge valve stuck closed, purge line disconnected or blocked), if the Evaporative Leak Check Module pressure (gauge) does not reach the threshold within a predetermined time, the monitor determines a malfunction and stores a fault code.
Malfunction Criteria
Evaporative Leak Check Module pressure (gauge)>Threshold