my malfunction indicator comes on while driving and goes off after sometime . i sometimes stop immideatly and switch off the engine and turn on the engine after sometime and it goes off again. if there is a serious problem i think it should stay permanently. my model is nissan primera 2.00 diesel. any help or sugestion?

Take it to Autozone and have it scanned (free$) for error codes that will point you in the direction of your problem.