Does the e53 key send a security signal to crank?

[paramax55]

My 2001 needs a head gasket, so I fixed it today by buying a 2006. The new one is a minor basket case and I got it cheap because I was the only one who could make it run and drive. It has three keys.

What should be the "main" key I believe is aftermarket. It opens easily and has a cr2032 battery. The switches are trashed. Usually this key won't make the car crank. One time it made the car crank, but it wouldn't fire. Sometimes it makes the car crank and start fine. I'm pretty sure the battery is trashed.

The second key is just plastic, with no remote buttons, but it has a RFID (I assume) unit in a little slide-out tray. It starts the car without issues.

The third key is just a plastic emergency key of some sort and I haven't tried it yet.

I never ran into this issue with my other car because it only has one key, the battery is easy to replace, and I haven't really had any issues with it.

So does the key send a security signal like the old Chevy VAT system?