M1K VW, IcewraithUK, Millsy If the suggestion by Guy hasn't fixed your problem. Then what you need is someone with VAG COM to match your ECU with your immobiliser, very easy to do. I had this problem when changing my ECU with one from a later MK3. http://www.ross-tech.com/vag-com/cars/immobilizer2.html Hope this shines some light on your problems.