Could be a few things, so you'll need to get the code read off the ECU - then you'll have a better idea.
You probably don't need an OBD2 reader, you can probably use the paperclip method as described here... http://typeaccord.co.uk/forum/topic/12330-malfunction-light-where-to-go/page__pid__137515#entry137515 then look up what the result means here... http://typeaccord.co.uk/forum/topic/5672-error-codes/
Welcome to the club. Do a search for more info, if necessary, and let us know how you get on.