Check engine light just came on. 1st time. Oil/antifreeze OK. Started after picked up from car washing....dash controls had been moved during cleaning. Light now comes on at start up and won't go off. What could it be?
You should find out if the computer is displaying a fault code that would indicate some sort of problem......then go from there.
http://www.bmwe34.net/e34main/trouble/engine_codes.htm