pyccke87

ROM means Read Only Memory. It means it cannot be programmed with a newer remote, hence Read Only. As for replacing the key, the car you bought has the remote built into the KEY (a single button behind the Lexus symbol). When you purchase this key (from a dealer), he is saying that you also recieve a chip that you (or the dealer) would install into the car. This allows the car to "talk" to the remote. As it stands now, the car only knows how to "talk" to one remote, the one that you do not have. This would be the one that came with the car when purchased. Newer cars (such as ones purchased in 1996) have newer technology. This newer technology allows one to program a replacement remote without replacing the chip that allows the car to talk to the remote. This type of programmable technology is called EPROM which stands for Erasable, Programmable, Read Only Memory. In short, you can change the way the car talks to the remote with this type of technology whereas with plain ROM memory the only way to change the remote is to change the chip (that tells the car which code to listen for). BTW, memory is the medium with which any computer stores information. Sorry so long winded, but you requested clarification. I hope that I have done this as I have done the best I can as I am not a writer. I see numbers better as I am a Mathematics Major.

I do know one other thing, I was able to reprogram my keyless entry on my car. It is a 1996 SC400. I will post the steps that I used successfully in PDF format.

Here's the PDF. This worked for me.

For a mathematician, you write very well. Thank you for clarifying this matter. I have just bought a 1991 LS400. I noticed that the key and the car do not 'talk' i.e. no central locking function. Do you know the procedure to get the car and the master key talking again? I have put a new battery in the master key.

Femi

I also have just bought a 1994 SC400 and replaced the battery but still have had no luck in figuring out how to get it working once again. Any help would be greatly appreciated.