Did a Diagnostic Test as EML showing for some time. Test threw up expected P0420 Fault--CAT/Emission-- but also Fault U1900--apparently connected with Inst Panel Cluster. Cleared Fault Code Memory. OK!. Nowe have strange noise when turning on ignition--Pos II- but not starting engine. It sounds like something resetting--bit like the traveller noise you get when changing the Inks in your Printer . Noise lasts only seconds. Engine start is normal.

Any idea as to what this might be and has it anything to do with the U1900 Fault.