There won't be. The UCH controls the windows, locking, lights etc. nothing to do with engine management. (Or nothing that would show up with a fault reader)
The last one I replaced I bought from Renault Wolverhampton on here, for under £150 and paid a mate at Renault £20 to code it. Certainly not the end of the world.
Have you tried (with the ignition off!) to wiggle/disconnect/reconnect all of the wires to the UCH? Sometimes the plugs get damp and the copper connectors go green and corrode.
Alternatively, you could buy a secondhand UCH, ECU, key, lock set etc (for around £100) and fit it all yourself,
The other option of course is to just ignore it. I sold one with the same fault (and told the seller!) over two years ago and the car is still going strong. Being abused as a track car in Germany.