Do Not Buy/Install Used Modules
 

If anyone is looking to buy a used module beware. This may be common knowledge but I was not aware of it.
To quote senior member Opie "There are 3 components that work as a "System" for the Immobilizer to work correctly and allow the car to start. If swapping parts between cars all 3 components must be swapped/used in order for proper communication to start the car.
The main body ECU (network gateway ECU) *also called the BIU, it's the black box attached to the interior fuse box, the combination meter (gauge cluster) and the keys (keys will require swapping the ignition lock cylinder and the door/trunk lock cylinders).

If any of the parts are used/installed individually the system will not allow the car to start. Once any of these components are programmed together, they must stay together and cannot be reprogrammed to work individually."

If you have to replace one of these modules please do not waste your money and buy a used one. Buy a new one and take it to the dealer to be programmed. The other option is to get all 3 components from a donor car and install them together. Do not power up the vehicle until all modules are installed.

I hope that helps save someone from a mistake.

Thank you for sharing this information, I may need it in the future.

There are several threads of people successfully swapping just the gauge cluster so I am curious where this information is from as it seems inaccurate. Is there a better source than a "senior member"?

reh8388 - The Toyota tech who I took my car to, who by the way was unable to get it working, told me that there are 3 or 4 modules that are part of the security system. He mentioned the gauge cluster as one of them. If you put in a new gauge cluster and got it flashed at the dealer you would certainly not have any problems but apparently a used one will cause problems. I am still working on mine. Will update if I find anything more out. I mentioned Opie because he is the only person including a Toyota tech who could tell me what specific modules communicate with each other in the security system.

The gauge cluster is only in that circuit in twist-key cars. On push button cars you can swap the cluster out no problem.