My 2018 Lexus RX450H will not lock. When I shut the car off the display shuts off. I open the door and the display lights up and says door open, then beeps. I exit the car and shut the door the display reads key not found check key location. The car will not lock and the display does not go off. I have had a 2nd key made recently. It has worked ok for one week since key was made. Any ideas?

 

A bit confused. Did the second key work for a week, then stopped? Or has it only been a week since you got it?

 

Both keys work to start the car. No keys work to lock the car. Display stays lit up. Will not shut down

 

I need to answer your question. 😉. Everything worked fine for one week after new key was made

 

I’m confused. You said “key” but these cars don’t use a key; they do use a key fob. Is that what you mean?

 

Yes key fob

 

Did you install new batteries in each fob? With a dead battery in the fob, you won’t be able to lock or unlock the car from the outside but sitting in the driver’s seat the fob may be close enough to the ignition so that the passive RFID could allow the car to start.

 

This is the display. It never shuts off.

 

I can do that, but why won’t the display shut off? Do you think that is related to the battery in the fob?

 

I still suspect dead batteries in the fobs.

edit: Yes, I think it’s not getting the radio signal from the fob. But sitting in the drivers seat the passive RFID may activate enough to start the car.

 

[QUOTE=Mllongo;11269788]I can do that, but why won’t the display shut off? Do you think that is related to the battery in the fob?[/

 

Standing outside the car with no fobs nearby…hours after I have left it…the display remains on. 😕

 

I’ll try to explain to the best of my understanding. When you are outside the car, the circuit in your fob uses energy from the fob’s battery to transmit info back to the car, telling the car to unlock or lock or whatever, and along with that info it transmits the individual “code” from the fob (so somebody else’s fob won’t unlock your car). Without energy from the battery, the fob cannot send info back to the car and the car is telling you “hey I am not getting a signal from the fob”. However, the engineers realized that you will still need to start your car even if you have a dead battery in your fob. So the ignition switch push button emits a very small radio signal, very low power. It’s enough power though so that if the fob is close to the switch, even if the fob’s battery is dead, the energy from the switch’s radio signal is enough to activate a chip in your fob (a passive RFID chip) which responds with just enough “signal” to tell the ignition switch to allow the car to start. Passive RFID chips have very limited range, so ordinarily the fob uses its battery and radio transmitter to send its signal.

 

I'd say just get new batteries for both fobs.

 

[QUOTE=Mllongo;11269792]I agree with you on this. I could see a weak battery presenting problems outside the vehicle, but if it was strong enough to start the car, why won’t it shut down? Does the vehicle even poll the keyfob during shutdown I wonder? Replacing the batteries doesn’t strike me as a bad idea necessarily, but it seems like a stretch… Very curious problem. Sorry I don’t have anything constructive to offer. How close are you to a Lexus or Toyota dealership? Our dealer is open on Saturday and may be able to help. We have also seen all sorts of wacky problems if the 12V battery needs to be replaced. It might be worth checking that as well.