How to Fix a Braking Alert on 2004 Renault Scenic?

I have just bought a secondhand Renualt Scenic Mark 2 2004 1.6. It has had work done to the electronic dashboard which went blank and now only shows 2500 miles on clock although the car has done 52,000K. It also has a Braking Alert problem and every time the car tilts the audio alarm sounds and the braking fault flashes up on the display - I am assured that the brakes are working fine so this is very annoying! Anyone had a similar problem - or better still do you know how to fix it?