Car Alarms: 2001 pontiac factory alarm system, gm pontiac, gm vehicles

Question
my wife has a 2001 firebird.we have had the car for about 3years,and had purchased it used.after having it for about a year or better she went to the store and her car wouldn't start,when she wanted to come home.checked the battery,it was ok. had it towed home tried to find the problem.couldn'tsolve the problem and ended up having it towed to the dealer.they fixed the problem and said the source of the problem was that there at some time a aftermarket alarm system had been installed.they disconnected that system leaving only the factory system.now about year later we again have the same problem.it seems that the antitheft portion of the system has been activated not allowing the car to start.it thinks that it is being stolen.so the question is how do i reset the system so my wife can drive her car again.

Answer
Interesting.
  Good explaination too, so I can discount some
things from this equation.

Is there a worded "anti-theft" light in the dash cluster?
Or is there a flashing LED light perhaps?

There may be a PASSKEY issue here. If faulty,
it would not allow for the fuel rail to supply
the injectors. If this is the case, you can
either call GM/Pontiac/Chevy to reset and
evaluate the issue, or get a bypass module
intended to momentarily bypass the PASSKEY
system, and permanantly ground the imput,
thus not allowing the PASSKEY to engage at all.

If it is the aftermarket piece, it's doubtfull
that the installer even put in a starter disable relay,
since the PASSKEY is a resistor based immobilizer system,
and it would have be redundent, and possible defeating
the purpose, to even add starter kill here.

This just goes back to PASSKEY theory.
Our solution to bypass these systems,
is the PLJX bypass kit.

PLJX - GM Self Learning (ALL TYPES) Passlock Override  
PLJX is an auto learning override module designed to bypass all
GM vehicles equipped with Passlock I , Passlock II
& VATS.

See this at www.passlock2.com .

But before you buy this to solve your issues,
I suggest you call GM again to go
over it. They may cover they're own work
if this issue was not addressed the last time
& possible pick up the towing too.

Good luck.

ALARMTEK
CARALARMMAN.COM