Xantia Key

[mckenzig]

I have recently bought two plain keys with the chip in them. If I start the car with our existing key, take it out and replace it with one of the new ones, the car will start. Leave it for a few minutes and it wont start. The new keys will open the doors though. Any one got any thoughts on what programming I have too do?

[addo]

I have not seen the official protocol but my observations of a few immobiliser systems of this era, is that you can do stuff like you describe if no door is opened or locked/unlocked while the key is out.

If you were closer I could code in the new keys for a small donation to FCF.

[evilclive]

Yes, they do that. Surprised me too. Makes it a bit tedious checking if you've successfully programmed the thing.

You need a lexia/lexia clone and the 4 digit code to program it. It's pretty easy.

[wheeler]

If I start the car with our existing key, take it out and replace it with one of the new ones, the car will start. Leave it for a few minutes and it wont start.

Thats normal operation, if you dont open any doors after you take the key out the imobiliser takes a few minutes to arm itself, if you open a door it arms a lot faster.
As alreay said you need Lexia or some other key programing software/equipment & also the 4 digit security code.