When my wife tries to start her LS430 with her smart key in her purse, the ignition switch turns, but nothing happens. So she lets go, and tries it again, and it starts right up.

Is it the battery in the smart key, or the car?

 

is she able to unlock the car by touching the handle? I think that might help to tell if its the battery or not.

 

I'm sure the car battery is ok. Key batters are cheap I would change that battery first. I got mine at Toyota and they put it in. $6.00

 

Sorry I should have been more specific I meant the key battery as Lexman52 said.

 

The smartkey has a 2032 coin cell...be very careful when changing, on one of my two master keys, the door broke off, and the spring inside went flying. So now it's duct taped (classy). The other stays in a drawer. might as well change it, nothing to lose, but do use an authentic one (retail package, not knock off), I installed a knock off from amazon (as opposed to a retail packaged from amazon), and it lasted only 2 mos. amazon prices fluctuate, but sometimes the authentic 2032 are only 60-70 cents each in a 4 or 6 pack, I might buy 16 when it's that price...(if anyone understands amazon pricing, please explain--I bought 7440 bulbs in person at $7.99 for a 2 pack, then got spares at amazon $5.99. Last week they were $1.32, how does something fluctuate from say $1.50 to $6.00, or is it they're monitoring how much you browse)...

 

Sorry, couldn't find my own post. Car battery appears to be fine. When it turns the car over, it turns fast and starts right up. When she approaches the car, it recognizes the smart key as it allows the door to be unlocked or locked. It's just that sinking feeling when you turn the key, and absolutely nothing is there. Release the ign switch, retry, and it starts.

So try the smart key battery and retry is the consensus??

 

How about as a test, just put the key into the ignition, to see if in such a scenario, it never fails.....(I have noticed that every shop I took the car to, returns the car with the key in the ignition, human nature)

Someone else may know the system much better, but if this were a BMW, it's similar where you can, but do not have to put the fob into the dash. It does not charge, it has a 2032, just like Lexus (cars without the keyless system do charge the fob, that's different). So, if your 2032 battery were dead, the car can still be operated by pushing the fob into the dash...

Of course it would be easily tested, take the battery out of a smartkey fob, put it in the dash, and see if the car starts....but mine are too fragile to take the battery in and out....