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