How do I bypass the PASS-Key 3 vats system?

Unfortunately you have the system that is not able to be bypassed. You have a key that contains a coded message that sends the code to the theft module and that sends a coded signal to the PCM saying that there is a good key in the ignition and it starts the engine.

You are far better to try and repair the system as it is simply a key, module, and PCM. So more than likely one of these is the issue.

https://www.2carpros.com/articles/how-to-reset-a-security-system

However, there is an option that you can get a PCM from a number of different companies that does not require this code. So basically when the PCM get the ignition feed, it will start the engine regardless of what signal it gets from the theft module.

I attached the info below on this.

What I would do is starting with checking for codes and see if there are any that would point us to the issue as that may be cheaper then this module.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Let me know if you have questions on this and we can go from there. Thanks

Okay. If they diagnosed it as a module then they would most likely have had a code or some proof of that. It is the most likely cause if the PCM was replaced but I would need a little more info to confirm this.

However, just so I was clear. The PCM that I am talking about is a specific PCM that has had the theft system removed from it. This way when you turn the key on and there is an issue in the theft system, the PCM doesn't care and starts the vehicle anyway.

However, if you already paid for a PCM then I would try and repair it as well so let me know if they gave you any info on why it was the module.