My W reg Punto has recently developed a problem with it's city mode, it's constantly turning on and off as i'm driving along. The light on the dashboard is also flashing intermittently. If i hold the city mode button in it stops the light from flashing but the steering still swops between the two modes. I never normally use city mode so it a bit of a mystery as to why it's playing up all of a sudden, does anyone have any suggestions on what it could be?