2004 pontiac Grand Am with security passlock starting problems

Unfortunately you are correct, this
vehicle has the PASSLOCK II key
based engine disabling system, and currently it
is engaged. The sensor does not recognize &
retain the passlock reader chip in your ignition
switch any longer.

A bypass is required to circumvent.
If left unchecked, it will lock down the fuel injector
rail (as it has now), and you will need to
tow it in to GM for evaluation, and resetting.
Eventuall, the 10 minute over ride will cease to
work and you will finally be forced to visit
a Pontiac/GM dealer.

But, if you want to just remove this system
from the equation entirelly,
I suggest the PLJX bypass kit to get around
this issue.

This Passlock Bypass Module is designed to momentarilly
allow the engine to remote start by sending a proper
coded pulse to open the fuel rail passlock injector
cut off circuit.

The output from an alarm/remote starter
would then shut down the pulse, once it has detected
the engine has engaged, and preserve the integrity
of the passlock system.

That is it's designed purpose.

However, in your case, this input wire on the PLJX module,
instead of going to a momentary ground pulse from
an alarm/remote starter,
would go to a constant chassis ground, through
the bypass module, grounding out the PASSLOCK.
The PASSLOCK would then always be bypassed as long
as that wire is chassis grounded.

I can not speak about a damaged passlock system,
like if a thief has destroyed it, because I do not
get into this part of GM'S security application.
Coincidence to installing
after market remote starters, this does work on bypassing
passlock in most all GM vehicles,
including your year GM vehicle as well.

Also, this is a self learning, resistor sensing
and adjusting module. Once the VATS wires have been tapped,
you would press the program button to learn,
and it does. The car should then allow start
with any hardware store key.

Would this work for a 99 mercury grand marquis? If so what model from pljx to buy?