I lost my master key a while back and I was under the impression that I was basically going to get raped by the dealer, well good news people, if you lose your master keys and only have a valet, you can still have a new master key programmed, just find a local lock smith, make sure to ask him if he has the scanner to gain access into the mobilizer, the scanner will reset all keys in the vehicle, then he can program in a new master key from scratch. I only had my valet key and now I have two valet keys and two master keys, hope this helps someone.

 

Thx for the info but when you say "Master Key" are you refering to the OEM "SmartKey" with the trunk button?

 

Actually no, I own a 2002 ls-430, although the procedure shouldn't differ that much. I lost my master key and was only left with one valet key, after reading I was under the impression I was screwed and had to pay the lexus dealer to replace the computer. I think if you inquired some local lock smith's they would be able to tell you if they can program the 04+ smart key's, but in my case, he had his tool gain access into the immobilizer, from which point the car's computer went into learning mode, he then inserted a fresh master key and after doing some weird ritual ( opening the door 6 times, turning the key on and off 6 times ) I had a new master key with a remote. He told me that my car was on the border line year where they could still do the programming w/o any major work, I'm assuming for 04+ models he would have to pull out the immobilizer computer, pop the cover and manually clip on to the chip and flash it, lucky for me I had mine done w.o any major hassle aside from a shady ebay key seller.

 

Where do you find such detailed pics with part numbers and everything?

 

the ebay key may have worked if you did the door ritual? Edit- maybe he finds that pic on transponderisland.com?

 

on the 04up smart key you will need the master key to make a another master key.

 

Good to know and excellent news glad you got it corrected at minimal cost.

 

Does this need to be done at the dealership? Can a fob purchased off ebay be used? I just purchased an 05 with smartkey and it only came with one master only and I need to hurry up and get a spare or two made...Thanks

 

you will not be able to program your ebay smart key.been there done it.a complete waste of money.dont waste any money on trying to programing it.return it or use it for spare parts.i paid 195 dollars at a locksmith for a new smart key and 20 for program.good luck

 

We (a lexus dealer) can program any LS430 without a master key. You don't have to replace the computer. Smart key or not, it doesn't matter. Now, whether you (the owner), have to have a master key to program another key, I'm not sure.

 

you will not be able to program a master key with out a program on a computer and hook it up to the computer in your car.you have to go to a dealer or a locksmith.i called butler lexus and they said they need the master key to program a master key(smart key)