I take it you mean the orange one with the engine symbol - if it is you'll have to get it plugged into a diagnostic machine and get the fault code read - usually there is an emergency running program that allows you to dawdle home at a snails pace but as yours wont start thats a diferent matter.
My car used to do this. The light came on regularly but my mobile mechanic fixed it easily. Are you a member of the AA, if so get them to look at it for you.