Hello CL forum. I am a new member to the forum and a new 2020 RX350 owner as of 12/23. My new to me Lexus has been fabulous with exception that often I get a KEY NOT DETECTED on the display and obviously the car won't start until take the key out of my shirt or vest pocket and wave it around a bit in my hand then the car sees the FOB and starts. I took it to the dealership and they said that is a "normal" thing and there is nothing wrong with the FOBS. Obviously I changed both batteries out only to have the issue continue. Both FOBS do this. I called Lexus and made an appointment for this issue for Monday 1/15. I just can't imagine that I don't have something wrong here..... One time I had the key FOB in my dress shirt front pocket, no jacket and the car did not see the FOB only 10 inches from the steering wheel! I would like to know if you forum folks have any experience or insight on this issue as it seems nuts to me that the car design of transmitter/receiver can not see each other when I'm sitting in the drivers seat! When i took the FOB apart to change the battery, it was full of lint as in dryer lint. Who knows, maybe the FOBS went thru the washer/dryer.... I dunno..... All I know is that I feel like I shouldn't have to take the FOB out of my clothing pockets when I'm sitting in the drivers seat just to start the 350! Comments, suggestions, insight, some setting?, anything to help me be informed about this will be very appreciated. Thank you, Brian

 

The Lexus dealer I deal with has a "technology guy/person" that has helped me a few times, so might try that route. You can also google reprogramming a Lexus FOB and see what that gets you. I understand you just bought the car and expect everything to work, but if those keys were run thru the washer/dryer as you suspect, water and circuit boards usually don't play well together.

 

That's definitely not right. I always have my fob in my jeans pants pocket and have never experienced that. Dealer has to do something.

 

I agree with @ravenuer -- the problem is in the car, not in your pocket.

Unfortunately, tearing into that area of the "system" is not going to be cheap -- hopefully you got some kind of warranty because you're probably looking at several thousand dollars to replace a transceiver module..

 

Yes, I purchased the 350 as a Certified Preowned that is fully warranted -- thank you.

 

He said that both FOBS do the same thing. So, seeing that the odds of both FOBS going thru the wash are pretty slim, I will have to agree the problem is in the car.
Make sure you tell the dealer there are no other problems with the FOB like locking and unlocking the doors or opening and closing the rear lift gate.

 

Thank you, i will tell them that on Monday morning- Brian

 

I keep a carbon fiber looking wallet that is RFI protected. Sometimes, my FOB will not work in my pocket as the RFI wallet is blocking the signal.

 

And I will let you know the result of Monday's visit to Lexus Lancaster County!

 

I also have 2020 RX which never gave me any warnings about remote. No matter where remote is inside the car, it works. However with a previous car i owned i had a surprise where the battery in the remote died. I went to the pharmacy and purchased a pack of two new batteries. I replaced the battery in the remote, but to my surprise, it remained unresponsive. Concerned, I tried another new battery from the pack, but still, the remote remained lifeless. At this point, I started to panic a bit, unsure of what was happening.

I decided to call the dealer, and they advised me to bring the car in for further inspection. The technician at the dealership opened my remote, placed a new battery inside, and to my relief, everything started working perfectly again. However, on my way back home, I couldn't help but wonder what had caused this strange issue.

Out of curiosity and a desire to prevent future problems, I stopped by a store and purchased a voltmeter. What I discovered surprised me even more – every battery in the pack I had bought that day registered at ZERO volts. It turns out that the entire pack was faulty. From that day on, I learned my lesson and made it a habit to test the voltage of batteries before replacing them in any device.

 

Understanding that the dealer will resist this problem and claim it's "normal" (again), or it's a problem with BOTH your fobs, here is what I would propose to him. Tell him that if he will replace one of your fobs with a new one, and that fixes the problem, then you'll buy it. But if that does not fix the problem, then it's not a fob problem, and he needs to accept the car for repair service and fix it correctly. It should NEVER be the case that you can get inside the car and be sitting in the driver's seat with the fob in your pocket, and the car can't detect it. Dealer knows that is true.

 

I am just hoping they find resolution to this as the car still is under the the original warranty period and 2, it's a Certified Preowned vehicle that I just bought November 23'
It has done this "KEY NOT DETECTED" in the display about 8 times in my 3 months of ownership but as you and others have said, the vehicle should not do this at all when the FOB is in your pocket and you are sitting in the car. I called LEXUS North America and asked them about it and they too agreed it should not do this. They opened up a case number on this and she said she will call me Tuesday to ask if resolution on this matter has happened..... You would think logically the dealership would simply replace/program two new FOB's and send me on my way and if the problem still occurs, then it would point to the receiver in the car as the issue,not the FOB's. But what the hell do I know...? Thanks dibl, Brian

 

Well Lexus dealership was able to duplicate the problem yesterday (Mon) and they needed the car today yet to determine the source of the problem that being either FOB or 350. I'll let ya know......thanks - my suspicion is they'll have to make some phone calls to their tech folks on this one.......

 

Background: Have been in Europe for a few weeks. My wife went to take off in our 2020 RX after coming home and it wouldn't start. She came in to get my FOB and it worked fine. It did say on the dash that the battery was low. I stopped and got some fresh batteries and changed them both out. Mine works as new, with no low battery message. Hers still is like before changing the battery. It won't do anything except the red light flashes when pushing a button. When I try to start the car it says the key is not detected. I have tried a couple batteries and adjusted the metal contacts on the battery clip. The battery reads 3.32 volts. I am at a loss... It seems like the FOB has lost it's mind! Any ideas???

 

On my 10k service last month, I reported this issue to the Service Manage. He took my keys to check the mileage and came back telling me that he could find anything wrong with my FOB. I wanted to laugh, cause he was so thorough. LOL! I know there is not much we can do until the car does not recognize the fob. And hopefully, we will still be under warranty.

On a slightly different note, I had misplaced my key fob and was down to one (have since found it). I asked the price for a replacement FOB and was quoted $450.