I had trouble with programming the remote buttons of my replacement key. I followed both these threads with no luck:

https://www.clublexus.com/forums/ls4...key-98-ls.html

https://www.clublexus.com/forums/gs-...aster-key.html

I finally tried a combination of the instructions in these two threads and came up with one that worked for me:

Have both the master key (that has the buttons already programmed) and the new master key you want to program with you.

There is no need to use the existing programmed key. You just need to have it close by.

1. Open driver’s side door. Keep door open.
2. Use power locks to lock all the doors.
3. Manually unlock the driver’s door.

Steps 1-3 are optional. Just start with the driver’s door open and unlocked and the three remaining doors closed and locked.

4. Put the key you want programmed into the ignition and pull it out. Don’t turn it.
5. Manually lock/unlock the driver’s door 5 times.
6. Close and open driver’s door
7. Manually lock/unlock the driver’s door 5 times.
8. Put the key you want programmed into the ignition and turn it to the ON position and then back to OFF.
9. Remove the key. The door locks should cycle once.
10. Press and hold both lock and unlock buttons on the remote for more than 1.5 seconds.
11. The remote is now programmed.

This is probably common knowledge or of useless benefit for a 10 year old car, but I hope it might help someone.

 

Yeah this has been posted b4 but still useful info.

 

Thanks. Just tried this method on remote of an ebay key of 2000 LS400, and it worked.
Total cost is $54.
Dealer wanted $300 for one key.
The method provided by the seller did not work.

 

And, I followed this video to program the engine key.