I need a help fixing keyless start for LS430. It was working last week, but I pressed and hold a button under the driver side call "key". After that, I cannot start the car without using the key. Please help.

 

Welcome. Press the key button under the dash again and it should start working. That button above your right knee disables the keyless system to save power when your car is in storage.

 

This solution worked for me. Thanks!!!

 

I took my wife's car for inspection and the tech asked me where the key was because he couldn't start it back. I told em it was laying in the back seat that it would start as long as the key was inside the car. He asked me to show him, but sure enough, it wouldn't make start without the key. When I got home and told my wife she was mad thinking they messed something up... three weeks later as im waiting for my wife to get out if the Dr's office, I googled the issue and saw this and sure enough, it worked! I guess they hit that button I never knew existed and neither did they, but thanks, this will make her day.

 

The button to disable the keyless system? It is next to the TPMS reset switch, both switches are well up in the drivers footwell, go straight uo from your foot when on the brake or gas. They both feel the same, the TPMS switch is a momentary push button, the keyless is a two position switch.

 

One may wish to consider viewing the below pic ...

 

Anyone know if Lexus actually put the button there for this reason? To save power if you won’t be driving for a few weeks…

 

Yeah, it was just to delay the flattening of the car battery if left for a long time.

 

I wonder what Lexus considers a long time? More than 1 week? 2 weeks or more?

 

During the COVID pandemic mine lasted 7 weeks of not being used and it only just started. I guess it depends on how good your battery is.
I now plug in a battery tender if she's likely to be stood for more than a few days.