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Discussion Starter · #1 ·
I've always been a little curious about that. A while ago I found an Acura key that looked just like our Insight ones and I finally got around to cutting it open. I just did a quick search on the topic, and it's funny, all the descriptions say there's a "chip" inside the key. Maybe some of them have a 'chip', but this one doesn't seem to have one. This one has a tiny glass tube with a wire coiled around a tiny rod I guess. Maybe it's an antenna?? Or maybe it creates a current if it passes through a magnetic field?? I have a hard time understanding how something like this is 'programmed'... The glass tube reminds me of a reed switch. When a magnet passes under a reed switch, it actuates tiny contacts that are encased inside a glass tube.

There might be something else in the cloudy, obscured area, can't make out what's in that end. Doesn't seem like there's anything else, though... Yeah, I just crushed it, there wasn't anything else that I could see, though it all just sort of disintegrated.

Here's a couple pics:
91470


91471
 

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There is some circuitry in the opaque end asfaik.
There is, that would be the chip side.

The coiled wire is the antenna/power wire. A magnetic field in they key cylinder receiver powers the chip, sends a small brief coded message to wake up they key, and tells it to send its chip code back to the cars receiver. When the car side receives the message it double checks it and verifies its integrity within a very very short period of time. Short enough that its already done doing what its supposed to do by the time your hand finishes twisting the key to 'start'. Thats transponders in a nut shell.
 

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Yup, it's essentially an RFID tag, which is powered by the field winding (the coil you see), plus a rectifier and a really low power microcontroller. Whenever the uC is powered up, it broadcasts a pre-configured key and then waits for another (programming) pulse, which would only occur if a programmer was wanting to change the code said uC broadcasts.
 

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Discussion Starter · #5 ·
I'm bummed that I wasn't able to identify any 'chip' in the opaque end, when I broke the glass. It must all be super tiny, cuz when I squished that end there was nothing that didn't simply look like crushed glass... If someone else comes across an expendable key, tear it apart and try to break the end of the glass tube to expose any additional 'electronics'. Or actually, maybe break the clear end and see if you can pull the stuff out, so as to avoid ending up with seemingly nothing like I did.
 

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I'm bummed that I wasn't able to identify any 'chip' in the opaque end, when I broke the glass. It must all be super tiny, cuz when I squished that end there was nothing that didn't simply look like crushed glass... If someone else comes across an expendable key, tear it apart and try to break the end of the glass tube to expose any additional 'electronics'. Or actually, maybe break the clear end and see if you can pull the stuff out, so as to avoid ending up with seemingly nothing like I did.
The circuitry is potted in epoxy, as you can tell in your second picture. Definitely can't pull it out. The chip appears to be on the right of the capsule as well, you can see a silver-ish square.
But yes, a little bit of crushed silicon will be pretty hard to distinguish from crushed glass. ;)
 

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Discussion Starter · #10 ·
^ OK, I'm convinced - there really is something over there.
 
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