Intermittent Failures
Intermittent failures may cause CHECK ENGINE light to flicker or illuminate. Light will go out after intermittent fault goes away. These faults indicate a defect that may or may not be present at the time of testing, however, the corresponding trouble code will be retained in ECA memory.
If related fault does not reoccur within a certain time frame, the trouble code will be erased from ECA memory. Intermittent failures may be caused by a sensor, connector or wiring related problems. See INTERMITTENTS in TESTS W/O CODES article.