2000 Renault Espace speedo acting strangely

I was driving to work this morning when my speedo started giving out strange messages. According to the speedo, my Espace needs a service, has no fuel, and is running extremely hot. In reality, I have about half a tank of fuel, it is still a long way off needing it's next service and it's running at normal temperature. Actually, it's running completely normally apart from the heater fan not working, (something else that happened on the way this morning). I had a problem something like this in my Laguna but simply turning the ignition off, waiting a few seconds and then turning ignition on sorted it. This doesn't work with the Espace. Any Ideas? :(