My mk2f has an insert point to a USB looking fob. it is a conlog system. there isn't a lot of information about it on the internet and from what I've seen i think its an immobiliser. It isn't inserted into my car and everything runs fine, (I don't want to stick it in and my car doesn't start) Does any body know what it does? how it works? I have been wanting to know the procedure of usage but I am too scared that it may not let me start my car ect.

Thanks to anyone that replies :)

If your car works fine without the fob in, it's probably an old immobiliser that's gone faulty and been disconnected again, or just been turned off on the override. Conlog doesn't ring a bell, but there were loads of companies doing these things in the 90's-early 00's.

Edit: Just found a bit in an old thread here, http://www.golfgtiforum.co.uk/index.php?topic=110719.0 it looks like it might have been a dealer fit back in the day.

If you do a google image search, you'll get some wiring diagrams. It looks like most of them just intercept the starter solenoid feed, so if it ever did go faulty, the car would probably still push start.