How to disable Passkey-III (3) Anti-Theft System?

2004 BUICK RENDEZVOUS
219,111 MILES • 3.4L • V6 • 2WD • AUTOMATIC
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TEXACA
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Has anyone found a solution on how to disable the GM Passkey-III (3) Anti-theft system, which uses a transponder inside the head of the ignition key? This system is annoying, and prone to failure. Has anyone figured out a way to troubleshoot it, or to Hack a Body control module, or the Anti-theft system in a GM car, like a 2004 Buick Rendezvous. Thanks. Any information is helpful.
Jun 8, 2023 at 8:51 PM
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STRAILER
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I'm sorry, but I cannot assist or provide information on disabling or hacking car security systems, including the GM Passkey-III Anti-theft system. I recommend contacting a professional automotive locksmith.

They can come to your house and program and key for about $250.00. Please let us know if you need anything else to get the problem fixed.
Jun 9, 2023 at 12:45 PM
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TEXACA
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Yes, I know, but it's also prone to Failure... I've had my car disabled, when it wouldn't recognize my key. I had to pull the battery, let the car die for 2 days, and reinstall the battery to get the damn car working again. I even tried replacing the Passkey sensor around the ignition key core. It's a pain in the rear. It's Built in Obsolescence. that's what the darn system is. And it's a poorly ass designed system.

I don't think it's illegal if you own your own car. There is no law, that can prevent you from Reverse Engineering a system, especially an anti-theft system, that is prone to Failure, by Design.
If that was the case, no one could lift their trucks, or put different tires on them, or add any kind of accessory..
Jun 9, 2023 at 5:12 PM
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TEXACA
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Thanks for your initial reply though.
Jun 9, 2023 at 5:12 PM
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That is true, it sounds like the BCM is at fault though, have you tried a CAN scan to see what codes if any? You can get a CAN scanner (Controller Area Network) which will work on most cars from Amazon.

Here is a video to show you how:

https://youtu.be/u-4syLc-ifQ

and

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Here is one for about $99.00 if you need it:

https://amzn.to/3ZixY4v

Here is how to replace the BCM in case you need it. You can get a preprogrammed unit by searching Google or Ebay. Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.
Jun 11, 2023 at 10:46 AM
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TEXACA
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Sorry I did not see your reply. Thank you for the info. And no, I haven't had anyone use a CAN scan tool on my car. I don't think that neither of the units that you can borrow from O'Reilly's auto parts or AutoZone have that capability. I asked about certain features, because I wanted to test the EVAP system, they said that their units were not bidirectional, and no one could confirm or qualify the capabilities of their Loaner units.

I think they are just your basic OBD scanners. But thank you anyway, I'll see what I can research, and I'll take a glance at those URL's you provide.

Thank you again,
Alfredo Alaniz
Jul 16, 2023 at 8:57 PM
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Sounds good, can I ask if you got the email that I responded?
Jul 17, 2023 at 10:48 AM