if the sensor is not plugged in, then it wont flash.
it sounds like are getting mixed up.
are you seeing an orange flash or red one ?
turn your car to ACC, take of all the lights lit up, then post on here and circle which one you see flashing and coming on.
only the engine check light should flash
lastly you can check all yours sensors under ETC, SENSOR SW CHECK and look for any black highlighted sensors, these are ones that are not working