Hmmmm......................it could come from anywhere? Where else could it come from it was not from the dealer. It would be naive to think that Jaguar would approve any engine work as @skyking mentions above. Do you think the local tech is your friend and he will lie on your behalf if something engine related happens to your vehicle even though the chances would be rare. He is going to put his livelihood on the line for you.All that means it leaves a non descript code that could have come from anywhere...they are not going to deny you anything because it's there..they will simple remove the code as if it was a fluke..my Tech said IF and it's doubtful anyone would ask, but just play dumb.
Good luck to you my friend and I hope that "all that starts well ends well."