my rover died!?

i've a 220TD and on journey all dashboard lights came on and it jus died on me. Check under bonnet and it had blown a fuse so after changing that started her again but only got hundred yards before she died again. i was told it could be engine managment/ECU got a spare but wrong connector. during staring her over and over now the battery is dead but speaking to a few people they say that it has somethn to do with the imobaliser and i need some code to reset it. will this work if so where do i get this code due to knowone in my area seems to no.
thanks D.Bundy