Intermittent Failures
Intermittent failures may cause CHECK ENGINE light to flicker or illuminate and go out after intermittent fault goes away. However, the corresponding trouble code will be retained in Electronic Control Module (ECM) memory. If related fault does not reoccur within a certain time frame, related trouble code will be erased from ECM memory. Intermittent failures may be caused by a sensor, connector or wiring related problems. See INTERMITTENTS in TESTS W/O CODES article.