Parking break fault?

I bought my 05 reg grand scenic the other day and so far have a few problems with it ( as many of you seem to as well). I have the usual airbag light and service light on, the car runs fine with that so it's fine, just annoying seeing it there but now I get a parking break fault warning come up. When i drive anywhere and have to park, I pull the electronic break handle and it makes a really loud horrible noise sounding like its coming from the boot and beeps at me but.... it seems to hold the car even though it says 'parking brake off', I still leave it in gear to be on the safe side. It's just embarrassing going anywhere in the car, knowing that when you stop and turn the engine off it makes this horrible noise and beeps for a while. I need to get this seen to but don't want to go to renault with their prices, has anyone get anymore info on what might be going on here?? I'd like to feel like I know a bit more of the problem before I take it to the garage to get it fixed. Any advice would be much appreciated, thanks.