BC8

04 LS430:

Smart key not functioning, when I press any button it does not do anything, does not lock/unlock doors, isn't recognized by car for keyless start.

I've changed the battery in smart key twice to double check and still nothing.
Changed multiple fuses in case and still nothing.

Not sure what else to try. Only thing I can think of is maybe a receiver for the smart key in the car? Is there even a receiver?

I've done many searches on here and can't seem to find any solutions. Does this maybe require a reset from dealer?

A separate issue I'm having is the horn will occasionally sound off on its own until I manually open the door and press on the horn to stop it. Also, when I drive sometimes the horn beeps sparatically on its own. I'm experiencing this when during cold weather.

Any response is appreciated! I'd hate to take to dealer and get taxed for a ridiculous amount...but may have to take that route!

Viper6

double check the button for this system is "on" position under dash by right leg. If so and you have good battery, not sure but to take to Toyota or Lexus dealer to trouble shoot. Do you have secone smart key you can try to use and see if it eliminates some of your trouble... maybe that will narrow it down to a bad key?

BC8

Yup checked the smart key switch which is on. The second key was stolen so only have the one main key. It just stopped working all if sudden after working the previous evening.