In the two months that I owned my 98 E300D, the dreaded Check Engine Electronics message has came on twice. Yea, I know, most of the time it means bad MAS unit. In each case, I took an wait and see attitude as engine performance appear unchanged. In each case, the message went away on its own after about a week. I also noticed both times the light came on as I was running errands and having to shut off engine then re-start after driving short distances.

My questions are (1) If the light came on due to system detecting a temporary irregularity, is it supposed to shut itself off after a certain number of days or certain number of re-starts? (2) Do I need to take my car in - the next time message light comes on?