GM ignition key readers

[Ron Tyler]

Terry Martin wrote:
> 
> Craig Pugsley wrote:
> 
> > Do the GM car keys with electronics inside them that the ECU talks to
> > still just use resistors inside the key or have they changed to something
> > more secure (ie something electronic in the key)?
> >
> > If so, when did they change?
> 
> Ron Tyler <dcmckenna at worldnet.att.net> wrote:
> Just resistors. There are 15 possibilities and they range from
> 400 ohms to almost 12K ohms.
> & What spurs your interest on the VAT system?
> 
> Sorry to disabuse your notion Ron, but Delco has come out with more
> vehicle anti-theft systems than they can remember.
> 
> Starting as a running assembly line change on Vette's in late '85 &
> officially '86 they introduced "PASS-Key", which is what Ron is
> referring to. They progressively implemented the system in various
> vehicles, and came out sometime later with "PASS-Key II", which is
> similar. They have also introduced "PASS-Lock", which utilizes a Hall
> effect sensor attached to the ignition lock cylinder, with a activating
> magnetic embedded in the lock plug in various Yr& Models. There is no
> interaction with the key. They have introduced PASS-Key III, which
> utilizes the technology I believe you are referring to, which has an
> embedded transponder in the key head. It has appeared in late model
> products as a running assembly line change, and is the same technology
> as that used to tag animals. It's basically a proximity detector which
> provokes a digitally encoded response from the embedded transponder in
> the key head. In some of the vehicles there is also a "Universal Theft
> Deterrent", installed on practically a random basis, which is a factory
> alarm system. If the vehicle has remote locking capability it probably
> has the UTD.
> 
> Terry
> 
> http://mindlink.net/terry_martin/facts.html


   I own an '86 Vette, wired a'95 LT1 and have also owned a '95 Impala
SS. Other than possible resistor combinations, I have found them all to
be the "same". I was unaware of these other combinations' exsitance. My
apologies for any confusions.

    Ron Tyler