Shaboom

Went out to dinner last night. After dark, arrived back at friends home. Parked my 2021 350 ES in their driveway. Went in for coffee. We returned an hour or two later. Went to start the car. Nothin' happened. No crank, nothin'! Message came on directing me to hold by key fob in front of start button and then try starting engine. Started right up. What had I done wrong to cause this? Did I somehow have the headlights on manual and left them on? Car turned them off and this was the result? What the heck happened? What good did holding fob in front of start button do? It had been in my pocket where it always is when I use this car. Never any problem before.

TechNut

Pure speculation on my part, but is it possible your keyfob battery is weak? I realize it is a new(ish) car and the keyfob battery shouldn't need replacement yet, but sometimes batteries sit on the shelf before being installed or are drained from heavy use (perhaps you are just driving that new car too much - LOL). Perhaps a button was stuck or it was stored in a purse up against something that was constantly pressing one of the buttons and drained the battery?

A second explanation could be that you were perhaps playing with your phone app (showing it to your friends perhaps?) and unlocked the car from the app. Then when you get in the car (if it is STILL unlocked), it may require you to hold the keyfob up near the start button. This behavior was discovered by another member on the RX forum and I discovered that my RX behaves in this manner when I tried it. I have not tried this sequence on the ES but I wouldn't be surprised if it behaves the same way and it could explain what you observed.

Shaboom

Thanks for your thoghts.
Both explanations are plausible but I like the first one better than the second. Weak fob battery makes sense here. I'm due for my initial 5,000 mi. visit. Maybe they'll replace the battery under warranty. My guess is to get a new one from them, installed, without warranty protection will turn into a a $35 to $50 deal. I'll ask first, as that's something simple enough even I (with the help of a YouTube tutorial) can do for myself.

lesz

I had the same thing happen with my RAV4 hybrid one time a few months ago. But it did start immediately when I placed the fob near the start button. Even without replacing the fob battery, it has not happened again since then.

In my case, before this happened, I had been doing some changes in the vehicle's settings. While I was doing that, instead of starting the car, I had it in the "ACC" mode. I thought that it might have been the case that, with the car in the ACC mode for an extended period of time, as the battery drained a bit, it might have been the case that the car temporarily lost its ability to communicate with the fob and that the communication ability was restored after I re-started the car and the car's battery had a chance to return to its full charge capacity, but that is just a guess on my part.

I recently bought a package with 5 or 6 of the batteries at Walmart. The cost of the package was only around $5. Replacing the battery in the fob took only a minute or two. There are instructions in the car's manual that explain how to remove the back of the fob to get access to the battery. Again, it is quite simple.

703

Takes less than 30s to change the battery. Less time than it took for you to write that post.

Shaboom

I did it for the fob for our Audi. Yes. quite simple and I do have a few of those batteries left over in a six pack in my desk drawer. Maybe I'll simply replace the Lexus one preemptively.

Wilson2000

I wouldn't suspect the battery since the ES is a 2021. I find my fob batteries generally last 5 years+. That is, unless, the OP wears really tight pants and the fob buttons are being pressed inadvertently! Sometimes a weak signal is simply an obstruction shielding the signal's pathway. Perhaps something else in his pocket or on his lap, between the fob and the car's receiver?

Shaboom

I keep it in the little change container on left side of dash. I always have and never had a problem before. It may just be some flukey phenomenon that will never recur and will never be figured out.

bc6152

If you read your owner's manual you will find that the explanation that technut offered is correct. When your smartkey battery becomes depleted you hold it in front of the "start" button to start the car. This, apparently, is what happened to you. Time for a new key fob battery from Walmart... Changing is ezy pezy...

Wilson2000

I read earlier that you had the fob in your pocket.

Is the change container metal? If the battery has to put out added juice to communicate with the vehicle through any sort of shielding, on an ongoing basis, it could exhaust the fob battery prematurely.

Shaboom

Interesting.I have house key attached to it, too. That and coins could be the problem, as the battery (and car) are on,y 6 months old (post delivery). Not sure now if it was in container or in pocket at that time.
anyway, With help of a You Tube tutorial, I changed the battery. New one works like a charm and all is well. Coin container emptied now, except for key fob.

lesz

I'm a bit confused. If you are saying that you are putting the key fob into the coin tray in the car while you are driving, that should not make any difference. If the fob is anywhere inside the cabin, including the coin tray, center console tray, glove box, or your pocket, everything should work fine. On the other hand, if you are leaving the key in the coin tray or elsewhere in the car while it is parked, say, in your garage, that could cause a problem with depleting both the fob battery and the car's battery. Also, keeping the fob near coins, whether in your pocket or in the coin tray should not make any difference, either.

mikemu30

I replace all four of ours every Jan1. They're presumably good for more than a year but I treat it like smoke alarm batteries (even though ours are hard wired) so in theory will never have one go bad.

mikemu30

Not coins nor keys caused that. My coin tray is full and I have several keys attached to my fob. Never an issue.

Shaboom

Yes, absolutely. Fob remains in car, in our garage, 24/7 except when parked out in the world. Do the same thing with our Volvo and Audi. You mean fob cannot be left in car at night or when we’re away, then? Wow. That’s something I didn’t know and also explains why fob battery only lasts six months, (though a year or two on Volvo and Audi). Thanks!