Ian sorry I cannot help - but I have exactly the same problem - keylight comes on (97% of the time) and no start (the other 3% of the time it works !) Citroens seem to be replacing everything - 1 bit at a time but we havnt got to the dreaded ecu yet. surely there's someone out there who can fix this for less than £800 + vat + labour etc etc They could make a fortune (instead of the dealerships)