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 stored in ECM memory. If related fault does not reoccur within a certain time frame, related trouble code will be erased from ECM memory. Intermittent failures can be caused by a faulty sensor, connector or wiring. See INTERMITTENTS in H - TESTS W/O CODE (CARB) article.