I don't know how handy you are with car DIY, but buy yourself a MAXISCAN 309 code reader off ebay for £13.00
plug it into your car and retrieve the codes, then google the codes and find what the fault is and fix it yourself.
if you take it to a garage, expect to pay £30 + for them to read the codes.
they are a handy tool if your going to buy a car, you can find out if the're are any faults stored on the ECU before you buy.
peter
May 2014