is this reset crazy for wifes car.

[Err]

I don't understand why they have to be battery powered. They should use NFC technology, but then the dealer can't make money selling you replacement sensors when the batteries die I guess.

These stupid sensors are anywhere from $50+ and that doesn't include installation. If they had to be battery powered, they could've designed them to be serviceable without unmounting the tire. The reason we have them in the first place is due to the Firestone/Ford Explorer tire blowouts. The sensors didn't address the root cause though which turned out to be that the tires were getting compromised on the assembly line. No sensor in the world would help you if your tire explodes.

[EvilHorace]

The batteries on my pressure sensors on my 07 Camry all died. For a couple of months I got the low pressure warning light (which was not low pressure, just the batteries annoucing their failure one by one), and it finally went out for good. Good riddance. I chevk my tire pressure every couple of weeks anyway. Never have trusted those sensors.

I don't understand why they have to be battery powered. They should use NFC technology, but then the dealer can't make money selling you replacement sensors when the batteries die I guess.

They aren't battery powered. Whoever told you that didn't know what they're talking about.
Odds are that they simply weren't correctly initialized and if that's not done right, the tire light will come on whenever pressures get to that point, like maybe as low as 30psi and on a cooler day, that can happen if you originally filled them to 32 psi.
The way it should be done is to have the low point set at 24 psi, then fill the tires to 34. That way, you won't see that tire light unless it's actually low from a real leak.
I doubt that your sensors were ever really all failing, more that wherever you took the car to didn't know a solution. Your 07 Camry and an 07 Lexus ES uses the exact same sensors and system. I've never seen bad sensors on those to date.
...but as mentioned above, the spare (if full sized) also has a sensor and needs to be checked as well.
The system works fine if the sensors were initialized correctly when the car was new but sadly, few dealer "techs" know or care how to do that right.

Lexus has used tire pressure sensors since '04 and I've never seen or heard of a tire pressure sensor needing a battery. They can fail but that's not common.

found out thanks to are government. this is now a requirement on all new car's sold in the states. no wonder cars cost so dam much

Actually it all stemmed from Fords fiasco with early Explorers and Firestone tires. Ford had the wrong tire pressure (too low) listed as being recommended and then add neglect, over-loading, stupidity, etc and bad things happened.
As of '08, all cars in the US had them but that system is only one of hundreds why cars are now so costly. The tire press. system in itself isn't all that costly.

[FlyingPenguin]

Evil: I mentioned that the sensors stopped working to the owner of my tire store (old friend, former client, known him for 16 years and I don't take my cars for tires anywhere else), and he mentioned the batteries. He said they use a lithium battery, and they don't last more than 6 or 7 years or so. He sees it all the time. He said the batteries are not serviceable, and you have to replace the whole unit, which he doesn't recommend bothering with on an old car (he's old-school like me - what's so hard about checking your tire pressure every couple of weeks?).

I did some Googling just now and it looks like a lot of cars used battery powered TPMS sensors back in 2011:
http://www.tirereview.com/changing-tpms ... batteries/

Battery Replacement
A depleted battery can’t be exchanged, so the entire sensor must be replaced.

Rigney says potting material inside the sensor housing secures the electronic components and protects them from the harsh environment inside a tire. “In order to remove a battery, the potting material would need to be melted. Heating the material could damage components and allow the battery’s lithium to seep out of its housing and into the environment.”

So maybe my Camry and the Lexus DO use NFC, and my sensor electronics just died. I do know it doesn't work at all anymore. After that last gasp when the light stayed on for 2 months, but all my tires (spare included) were at the proper pressure. Then it went off for good and never worked again, even when I got a completely flat tire from a nail a few weeks ago. No worries, I really don't care.

NFC makes a hell of a lot more sense to use in these things. No battery required and since the sensor can be located within 2 feet of the receiver, NFC would work fine (NFC is what's used in automated toll booth pay systems). NFC would also reduced radio interference since it's extremely short range. I remember reading an article about a radio telescope in VA where radio transmissions are restricted in the vicinity (no Wifi or cell towers allowed by federal law!), but they they pick up interference from car tire sensors all the time and have to filter it out.

[EvilHorace]

I've been with Lexus for over 8 yrs now and to date have never heard of any tire pressure sensor "battery" issue. The only times we've replaced sensors, maybe one per car is on much older Lexus cars like SC 430s and GX 470s (big SUVs) and these are now older, high mileage cars and then only needing one sensor during its lifetime, not frequently. To me, an '07 isn't very old but then my newest car here is a '95 with 234K miles.
I don't know about other cars tire pressure systems but Toyota/Lexus doesn't typically have problems with them other than not having them properly initialized and/or actually having low air pressure. The systems are basically good otherwise.
Another thing that can easily happen is that if the tire installer doesn't know how to change tires with those sensors (and there's a "trick" to that), the sensors can easily be broken.

As for the good old days of actually (at least) LOOKING at your tires before driving.......everyday I'm on the freeway and see cars driving with at least one low to almost flat tire. Most people don't even look at their tires or notice that the car isn't handling right either. I always try to pass people like that because when that sidewall blows, I don't want to be behind them.

[FlyingPenguin]

Yeah, I tend to check tires every time I tank up. That's every 2 weeks for me usually. Old habit, and a good habit.

[EvilHorace]

More on this:
If what you were told about Toyota, Lexus tire pressure sensors was true, not only would I have seen it but there would have been a recall long ago because Lexus customers wouldn't have put up with that (needing to replace multiple sensors on every car). Known to you, trusted or not, your guy was wrong about your car and whatever was wrong with your car could have been fixed by the right Toyota tech, you'd then still have a working system. Now, I'm sure that you have a permanent tire light glowing on your dash, probably covered by electrical tape.
Believe it or not, until about 2 weeks ago, if an owner of any older Lexus (even late '90s cars) lost their keys (even second, third+ owners), Lexus would buy them new ECUs, keys and pay for re-programming. That's about $2K customer cost per car and most of those cars are hoopdy's too, not worth that kind of money.

[FlyingPenguin]

Nope, no permanent tire light. It was false positive for a couple of months, and then went out and stayed out. Now it only comes on briefly when you start the car as part of the indicator light diagnostic test, but that's it. Had a flat tire a month ago, and the light never came on for it.

Car was out of warranty by the time it failed, and like I said, doesn't matter to me. I'd have paid for a repair if it was worth it, but I have never relied on that light. It's less than useless on that car since it doesn't tell you WHICH tire, just that one of the 5 tires is low.

I prefer the way it's implemented on my Yukon. I can see the individual pressures of each tire. However I still check those tires myself on a regular basis.

[Pugsley]

You know insurance company use this info during crash investigations. If they see a low tire or some other thing they can then blame it on that and say your car was not properly maintained and not pay you.

[EvilHorace]

It's less than useless on that car since it doesn't tell you WHICH tire, just that one of the 5 tires is low.

Until a couple years ago, Lexus finally started doing that as well but only on a couple models, not across the board.

It's stupid to have a system that tells you that one in 4 or 5 tires, could be any, is low requiring people to check them all. Checking the spare in the most popular SUV, the RXs (until a few years back) meant lowering the spare via tools from under the vehicle. A few years back they finally switched from full sized (with sensor) to a space saver w/o sensor.