Guys it is not the electronics (chip) in the key. There is magnetic slug which is embedded in the shell (remains behind even if you remove the electronic module... also battery or no battery in the key does not affect the imobilizer).
The signature of the flux is registered in the car's ecu as allowed to start. Master key allows new signature to be stored in the ecu.
They said it was not possible and cannot disable the immobilizer. Saying the only option is to replace the ecu. They also said they don't have the ability to tell if the key is transmitting anything. The flashing security led has to be off before the car will start. Mine is flashing even with key inserted.
Edit: will probably get it towed back home since may not be worth to fix. They did mention that it maybe possible to disable immobilizer aftermarket but they don't do it at dealership.
Damn. New twist - service advisor offered me service to reprogram ecu with new key by someone not affiliate d with Lexus for $800 as opposed to Lexus replace ecu and parts for around $1500. Caveat is that the reprogramming must be done at lexus even though he doesn't work for them. Gonna get it towed back home.
Edit: service advisor said parts guys know a locksmith that can reprogram and cut key - my guess why it has to be done at Lexus is that locksmith needs Lexus equipment to do job. Also mentioned it was a lot of work since they have to remove ecu etc.
Edit 2: they don't have any idea what happened - this is my concern about fixing since it can happen again. Good part is that they did not charge for diagnosing.
Wow you have certainly have "gone to hell and back" with this issue...at this point I would maybe suggest that you look on ebay (possibly other sites) for a used ecu with remotes that go to it you would bee looking anywhere from 300-600$ that really sucks!
Great glad it helped! 120 is a steal! The only reason why the eBay one cost 360$ is because it comes with the whole steering assembly And the key ring I am really hoping this works for you! All of us here on CL get a little pain in our hearts when we see people struggling with issues but the best of luck to you!!
Great service and highly recommend Enny and his company above - although they are crazy busy. He is a former Toyota/Lexus automotive locksmith, very knowledgeable and loves what he does.
They came to my house last week and could not get the car started -discovered that the key was missing the immobilizer chip (gray magnet looking piece) and that the ECU had problem reflashing. So they took the ECU and key with them to work on.
Came back late tonight with reflashed ECU (had to desolder and plug new (IC900?) chip in order to reflash). Installed ECU then reprogrammed with (3) keys - (2) dummy and my one key. Car started up like a champ.
Still find it strange that the key was missing the immobilizer piece. Must of popped out when exchanging key shells. I do remember that the black membrane was stuck to the plastic shell in one area so that the two pieces became separated (membrane and electronic case) - so word of advice to those moving electronics to new keyshells - do the switch in sterile work area where you would be able to detect the immobilizer piece falling out.
Finally, for those who are wondering, all is not lost when you lose your one and only master key. You can get the ECU reflashed to virgin, and then reprogrammed with a new master key.
Thanks to AnthonyMtz and the legendary salimshah. salimshah FYI Enny confirmed what Lexus said in that there is no way to disable the immobilizer although if that option was available, I would have gladly taken it.
Last edited by tarzan17; 08-30-14 at 10:04 PM.
Reason: Missing thanks !