00 4runner limited engine immobilizer question
 

Lost the keys to a 00 limited> It has/had a chipped key and engine immobilizer. If I swap in another limited ECU with matching ignition core/key will the engine start? What about a regular SR5 ECU without a chipped key or immobilizer? Any help appreciated.

Why not go to your dealer and get two new chipped Key blanks cut and programed

Then you don`t need to change all the other locks to fit your new ignition key

If you can find a matching ECM with chipped keys Good luck

For some reason they gave sum bs about needing a new ecu and keys to the tune of 1600. Also I'm in New England and can pick up complete 4rummers with rotted frames for 400 which I think will be less than what a dealer will charge. So will another limited ecu with keys work? Changing the lock cores isn't a big deal for me.

Did anyone ever answer this question? I had my stolen '99 limited recovered without one remote and transponder key. I have the other set. I also have steering wheel and components from my salvaged '00 4Runner limited. I want to swap the ignition key and locks, etc. and will swap the ECU if I have to but can I just insert the ignition key lock and it's related transponder key components without having to flash the ECU? I think I read something about having to flash the ECU. I'll keep looking for information but if anyone knows how to cut to the chase ... or maybe I'll just see if the key components work. It's undoubtedly just a digital signal to the ECU which gets generated by those little modules on the steering column once the key is a match is my guess. One even has an RF label on it. The remotes themselves might be another issue but even if someone gets in the car they can't start it without the right transponder key. Any info is appreciated. Thanks.

OK. I can do that. What numbers am I looking for? Maybe I can figure that out. I have all the components and keys/remotes from my salvaged 4Runner. I saved all that ˟˟˟˟. The motor/tranny from it is in my '99 as well. Glad I got it back.
Shocked actually. Shocked it was stolen from a private lot by an open kitchen window in the first place too. But ˟˟˟˟ happens. Thanks.

I found it amazing that they didn't make a way to flash the ECU for replacement Keys and FOB, and to program new keys or FOB you must have a key, I thought I read it was possible if you talk to the right person, but then digging deeper it seems this particular ECU with immobilizer is not re-programable without a key. And then the sequence to add a key or FOB is something for the books, what a PITA.

cchinny's answer above pointed me in the right direction. I'm an old electronics tech but hadn't really studied the theory on the transponder keys and ECU except to know they had to be programmed to match. I was looking for an easy way out, but there wasn't. Obviously you have to replace all the locks to match the keys as well. I'll post a few pic's of the parts I replaced.

Other than that the following link gives a better look at how this all works. If you're a tech like I used to be it might help if you have to go this deep into it, but I'm not into bit fiddling. Never was as a tech but I did a lot of troubleshooting in the early days of digital. Kudo's to the guy who wrote it up. It helped a bunch.

https://www.instructables.com/id/DIY...-or-Swapped-E/

Later.