Starting a new thread to not overlap my ignition switch issue... does anyone know how many master (smart key) keys you can have (2005 LS430), and how additional keys beyond two register in terms of seat memory or other presets? I have 2 masters + valet, but thinking of a adding a third master to avoid need to physically insert key into ignition after recent oddball problem with that, plus as a convenience since valet key does not open the trunk, etc. There are 2 seat presets (actually, 3... third is not tied to a key for me at least). If keys are "numbered" somehow (key 1 selects driver memory 1 when approaching the car, etc), how would an additional key get numbered? I do not know if the car originally had some kind of master key #3 for memory position 3.

I am not so concerned about seat memory as much as seeing if you can have a 3rd smartkey without it interfering with others. I would be OK if is truly acted as a duplicate of key 1 or even better if it tied to currently unused seat memory button 3. I am guessing I would go to dealer both for the key and programming, but figured I'd check up front here on how it works. I'm not sure if system has changed since 2005 but want to avoid surprises...

 

There is room for 6 keys in the key-table accessed via tech-stream. 4 should already be filled from when the car was new and first sold - 2 masters, one valet, and one wallet key. So there should be two empty slots unless someone over the years had to get replacements or new keys added and the other 4 slots were not modified/deleted