l haveRenault Megane 1.5dci 4 years old. Just recently l have injector fault message displayed along with the service light being on. l have read that this may be a software problem. Has anyone had experience of this and does anybody know how much this is likley to cost me to fix?

Its probably not a software problem - more likely to be a ''glow plug'' (combustion chamber pre-heater plug) failure.
Happened on my 1.9dCi a couple of years ago - but it was still under warranty so do not know the cost.

Have a look for similar problems on Mégane owner is forum at http://meganeownersclub.co.uk/forum/
http://meganeownersclub.co.uk/

sounds like a job for a garage, about £150 at a guess

l have a megane (petrol) 53 reg.my service light was on and it used to cut out.The garage told me it was a faulty management system. It cost me £175

The fault is most likely to be faulty a Pre-heater plug(s) but could be anything. Get it checked at garage mate.