Please see my post entitled problem. I have exactly the same issue, so I started with replacing the solenoid, and that cured it for a while, but after a week or so the fault reappeared. I have heard that vw will contribute towards and yes the part alone is £300 plus fitting. So, dependant on your warranty position, I would get it replaced. The advice I got was eventually it will fail, which will cause either a rough idle, or an inhabiting to start.