I have an 04 LS430. My smart key is not working, does not lock/unlock doors and trunk. I have to use the metal key manually to unlock. I'm able to insert fob into ignition to start car but cannot without it, says key not detected. Replaced the battery in fob too. I lost my spare as well.

Any suggestions?

 

One of the many probabilities is the driver door actuator. Do all the doors lock when you use the lock button on the driver door? Once the driver door actuator goes bad, you cannot open / close any of the doors using the smart key nor will the "proximity" sensor work.

Source of my information: Exact same thing happened to me. Put off the $ 200 part replacement for nearly 6 months before I was fed up of using the metal key. Best 200 ever spent and more appreciation for the auto proximity unlock + keyless start

 

All doors do lock when I manually lock it from inside the drivers door.
Hmm actuator huh? I want to mention too that I had the car sitting there without being started for about a month a half while i was away. Had to jump my car battery when i got back. The key fob worked for a couple days after then stopped.
Do you think this had something to do with it as well?

This morning the horn went off on its own...I manually unlocked then door and started car but horn was still on until I pressed the horn...wtf? Car has been acting weird.

Let me know what you think or how to troubleshoot before I replace possible issue of actuator.

Thanks everyone!