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Way back when I bought my 2001 in 2003 I was told by dealer if I had lost all but 1 master key to have another made as spare because if I lost that one it would be several thousand dollars to correct. Times have changed now where module doesn't have to be replaced maybe. That $575 might be the cheapest way now..don't know. Problem is if you loose that valet key you are stuck. Really depends on how long you are planning on keeping the car as our cars are getting a lot of age on them. What I would do is call Lexus dealer and get a quote for them as that would be a max figure and go from there. If you have techsteam software and a master programming is easy.
Well called one local locksmith - he quoted me $350 and had to check a few things out - He called me back and said he can't do it but Nick his other locksmith friend can for $575. I said I would take Nicks name and get back with him. So I cruszed on Google and put in Lexus locksmith for my area and called one guy - he says $150 - and I say "You better check this out because that seems kinda low" - He says nope I can do it. He shows up and I show him the smart key and whamo - "Oh - that key? I can't do that" lolz - the journey continues
Ok...Looked this up and here is a link for service to do what you want to do. They will make 2 masters without remote and you then can program own for $150 or for $350 will be 2 with remotes. You send in your ECU with info and they reflash...https://www.ebay.com/itm/286057256646
Way back when I bought my 2001 in 2003 I was told by dealer if I had lost all but 1 master key to have another made as spare because if I lost that one it would be several thousand dollars to correct. Times have changed now where module doesn't have to be replaced maybe. That $575 might be the cheapest way now..don't know. Problem is if you loose that valet key you are stuck. Really depends on how long you are planning on keeping the car as our cars are getting a lot of age on them. What I would do is call Lexus dealer and get a quote for them as that would be a max figure and go from there. If you have techsteam software and a master programming is easy.
Thx - yes I am thinking about speaking with a service advisor at Lexus - Thx for posting
Ok...Looked this up and here is a link for service to do what you want to do. They will make 2 masters without remote and you then can program own for $150 or for $350 will be 2 with remotes. You send in your ECU with info and they reflash...https://www.ebay.com/itm/286057256646
You know I can be the Guinea pig and try this - I think it's worth a shot but will review this seller - thx for the link and am checking it out. (edit) Geez I just noticed these guys are in Daytona - that is just up the coast - Gonna see if I can find their number and I did and will call them - Thx again
Last edited by Holden53; Oct 12, 2025 at 09:41 AM.
This might be the perfect solution for you. Your key most likely will no longer work but ask them if they could as part of the process to reprogram your valet key at same time at not charge. You should be able to do it on your own later with techstream since you will have the master if want also. Hope it works out ok.
There is no green light on the fob. There may be red one when in range or if pressing a button on the fob. There is a blinking green on the left side of the dash, but I never think about when that turns on. What is not working? A specific area like the trunk, but doors and starting without inserting the key does work ? If nothing smartkey-related works, do you have the smartkey system turned on via the button under the dash?
Yes, you are right - it's blinking red when he is standing at the driver door with the car locked
This might be the perfect solution for you. Your key most likely will no longer work but ask them if they could as part of the process to reprogram your valet key at same time at not charge. You should be able to do it on your own later with techstream since you will have the master if want also. Hope it works out ok.
ECU was shipped today and will arrive in Daytona tomorrow. I will update once I get the ECU back.
New update 10-14 -
Well, I tried this and the locksmith has this ad up on eBay but unfortunately this is not an ad for a 2004 with smart key - yes the ad says on eBay 2004 but its for the earlier 01/04 model. Evedently there was a mix of old and new in 2004 and the smart key was available on the ML and UL probably. (that is a guess) But anyway he refunded my money and I am getting the ECU back. And that brings up another issue. He shows the ECU and with the smart key you have to flash the security ECU which I think is behind the glove box (guessing on this also) but it was explained to me.
The SC shares some common equipment with the LS regarding the smart key evidently. The locksmith sent me this picture. This is another dead end - and it sounds like the real cost is again what we know and that is the key & flash - And these keys are even more specific. There are part numbers for my car that are not available. The common part number just looking at websites is the 2004-2006 Lexus LS430 OEM Smart Remote Key 89994-50241 HYQ12BZE. I inquired at Key4 (another supplier to OEM keys) and they are saying my actual part number is 89994-50311 based on the VIN. I am wondering if this is another "guess the toyota/lexus variant part number"? Anyway I am going to Lexus to inquire
I am going to speak with Lexus just to see what this retail cost is to program a master key. This is getting pretty deep and I am getting my waders on. The guy Nick has with the $575 is looking more and more the only other way unless it's retail at Lexus
Last edited by Holden53; Oct 14, 2025 at 04:41 AM.
