'97 ST202 immobiliser bypass?, (or, why you should always have a spare key) Options

[Scrapocaster]

Hello 6GC!

So, because I'm an idiot, I lost the only key to my UK-spec '97 GT a few months ago. To cut a long story short, I've managed to get a key that'll only unlock the car, but nobody is willing or able to make a key for it that'll start the car. I've got a locksmith working on it currently who made a new key and supposedly reprogrammed the ECU to work with it, but it makes no difference - both that key, and the blank non-chipped key I have, only start the car for a second before the immobiliser cuts the fuel and the car dies. Apparently, this particular immobiliser (fitted at the port before being delivered to the dealer in 1997) is notoriously hard to bypass, but I know it's been done. Toyota won't help anymore, though. So what's missing?

All the info I can find is 10+ year old forum threads, where anyone with info understandably did it through PM, so I've got nothing. I'm desperate to be able to drive it again I've owned the car for nearly 6 months and it's been sitting on my drive for 5 of those months!

I've probably missed some detail (it's been a huge ordeal of back and forth between several people and issues), so remind me if I've missed any info. I'd be so massively grateful if anyone had whatever info I'm missing.

Thanks!

[Box]

I'm not sure about Toyota, but GM had immobilizers and chipped keys during the same time frame and all that "chip" is is a resistor that the security system looks for through the ignition switch. I think there was like 20 different values or something, but of course if like you and the key is missing you'd be **** out of luck and would have to try every known value versus just measuring what's on the key to know what to use from the start. You might be asking me, "Why the **** are you telling me about a GM security system?" Well, during the 90's GM and Toyota were buddies with cars like the Geo Prism and Toyota Cavalier so it's possible the Toyota immobilizer system is similar if not a copy of the GM passlock system. I'm not saying that's the case as it's just speculation, but being it was the 90's and GM was really the only one using that kind of tech at the time and given their relationship with Toyota... Might be worth looking into.