p.a.s.s. key
http://gmcanada.com/english/firstnew..._features.html
http://www.gm.com/company/gmability/...ft_deterrence/
http://www.pagerealm.com/fbody/faq3.html
A: PASS-Key II works with a small resistor chip embedded in your ignition key. This chip gives a certain resistance. When the ignition key is inserted into the car for the very first time at the factory the computer controller memorizes the exact resistance of that chip and will not start again w/o it.
This provides pretty good protection against all but the more sophisticated thief. A knowledgeable thief can get around it with the right equipment, but the time to steal goes up considerably.
http://home.t-online.de/home/O_Scholz/vats.html
Patent:
http://patft.uspto.gov/netacgi/nph-P...S=PN/4,296,402
http://mainstreamtopics.com/forums/i...showtopic=1016
The computer needs that resistance inline to act properly, yes you can simulate it with a resistor that matches the resistor in the key.



