2002 Vauxhall Corsa engine cut out

My wife was driving her Corsa when the engine suddenly cut out.managed to push the car home, but will still not start. Had 11 months trouble free driving before this happened. Checked timing belt which is fine and fitted new battery in key fob no change. The engine electronics/immobiliser lights is lit on the dash,before this the light used to come on now and again but car performed great. I have a diagnostics code reader but it only works on petrol cars