I bought a 2002 SC430 recently and it had only one master key and one security (credit card) key. I bought a really expensive one from the dealer for ~$200 programmed and everything, then I wised up and bought a couple more from this great vendor I found on eBay call MR Remotes. Both of the new keys I tried to program myself and got cut locally at Lexus for $25. The keys cost me less than $100 compared to the $200!

Now the problem: The second key I bought (master key # 4) will not program at all. It is brand new. The key will open all doors manually, so I know it is cut right (from Lexus as well), however when you try to program the immobilizer and the remote, they don't work. I have used both the instructions from this site as well as the key guy's instructions. No luck.

Could it be that the car came with another master key, and it is out there somewhere and this is the reason why I cannot program this additional key? Is there a way to cancel that key so I can get this one programmed? It says on all tech pages that four master keys is the max. I'm wondering if this might be my problem. What can I do with this extra $100 key that I have that is cut for my car, yet the remote doesn't work and it won't start? Can I get it made into just a valet key that just starts the car and doesn't have remote functions? I don't have one of those, except for the credit card one.

Thanks in advance for your help.