About a week ago I was driving and a warning message "Engine Fault. Repair needed" came up and the Service word lit up. The car's not due a service for the next 6 months or 13000 miles. I bought a diagnostic unit but when I plug it in and try to run it, it says it can't connect to the engine ECU but it gives details of all the other bits like aircon etc so the connection is being made This now happens every time I start the car. The car seems to be running normally otherwise .Any suggestions would be much appreciated.